JP2004315917A

JP2004315917A - Method and apparatus for heat treatment, and heat treatment furnace used for the heat treatment method

Info

Publication number: JP2004315917A
Application number: JP2003113382A
Authority: JP
Inventors: Kazuhiko Katsumata; 和彦勝俣
Original assignee: IHI Corp
Current assignee: IHI Corp
Priority date: 2003-04-17
Filing date: 2003-04-17
Publication date: 2004-11-11
Anticipated expiration: 2023-04-17
Also published as: JP3956888B2

Abstract

<P>PROBLEM TO BE SOLVED: To reduce output of a heater facing to a heat treatment holder, and to improve thermal efficiency. <P>SOLUTION: This heat treatment apparatus has the heat treatment holder 17 that has one pair of tabular connectors 18 made of a C/C composite arranged at a desired spacing in parallel, and integrally connecting each of both ends of a tabular resistance-exothermic part 19 made of the same material, which is arranged so as to extend in an orthogonal direction to the connectors 18 in an opposite plane to each connector 18. The resistance-exothermic part 19 has greater electrical resistance than that of the connector 18 so that when a current was passed through the resistance-exothermic part 19 between the connectors 18, the resistance-exothermic part 19 can generate heat due to the resistance. The heat treatment method comprises, when heating an object 12 to be heat-treated which is mounted on a hearth 10 of a heat treatment furnace together with the heat treatment holder 17 by the use of the heater 11a, contacting the heat treatment holder 17 with an electrode material 22 to pass the electric current through it and heat the heat treatment holder 17. Then, the heater 11a can eliminate necessary heat for heating the heat treatment holder 17 from its output. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は鋼材の焼入れ、焼戻し、焼鈍し、焼ならし等の熱処理や、セラミックス、磁性材、炭素材、複合材等の焼結、焼成のための熱処理を行うときに用いる熱処理方法及び装置並びに熱処理方法に用いる熱処理炉に関するものである。
【０００２】
【従来の技術】
金属や合金製の部材、製品等の鋼材は、硬度、強度、靭性やその他の機械的性質を変化させるために、焼入れ、焼戻し、焼鈍し等の各種熱処理を施すことがある。このような熱処理を行う場合は、通常、熱処理炉内にて、熱処理対象物を所要の高温条件、たとえば、７００〜１４００℃、更に材質によっては２０００℃程度まで加熱した後、冷却するようにしてあり、上記加熱温度と、冷却時の冷却速度を制御することにより、各種の熱処理効果を得ることができるようにしてある。
【０００３】
又、セラミックス、磁性材、炭素材、複合材等を焼結、焼成する場合にも、それぞれ高温での熱処理が必要とされることがある。
【０００４】
上記のような各種の熱処理を実施する場合、真空中、不活性ガス雰囲気中等の制御した雰囲気下で行うこともある。
【０００５】
図９（イ）（ロ）は、上記のような真空中あるいは不活性ガス雰囲気下にて熱処理を行う熱処理炉として従来より実施されているものの一例として、バッチ処理を行う一室式の熱処理炉を示すもので、以下のような構成としてある。すなわち、前面部に開閉可能な扉１ａを気密に備えて真空や不活性ガス雰囲気等の内部雰囲気を保持可能な本体容器１の中央部に、断熱壁により囲まれた箱型の加熱室２を設け、且つ該加熱室２の前側壁には、開閉扉４により開閉自在とした処理対象物の搬出入口３を設けると共に、天井壁と底板には、ガス流通用の開口部５，６を設けて、それぞれアクチュエータ５ｂ，６ｂにより開閉作動される冷却扉５ａ，６ａを備えた構成としてある。又、上部開口部５の上方となる本体容器１の頂部に内向きに設置してあるファンモータ８の出力軸に、冷却ファン７を取り付けると共に、本体容器１の内側上部位置に、外部より所要の冷媒を流通させることができるようにしてある冷却コイル９を設けて、上記各開口部５，６の冷却扉５ａ，６ａを開放させた状態にて、ファンモータ８にて冷却ファン７を回転駆動させることにより、本体容器１内の雰囲気ガスを、冷却コイル９にて冷却しながら開口部５，６を通して加熱室２内に循環流通させることができるようにしてある。
【０００６】
上記加熱室２の内の低部位置には炉床１０が設けてあり、該炉床１０上には、上記搬出入口３を通して加熱室２内へ装入されたトレイ状の熱処理用治具１３や、バスケット状の熱処理用治具１３が載置されるようにしてある（図ではトレイ状の熱処理用治具１３を載置させた状態が示してある）。
【０００７】
更に、加熱室２内には、上記炉床１０上に載置される熱処理対象物を取り囲む少なくとも４面方向、すなわち、内底部における上記炉床１０と干渉しない所要個所と、天井部と、前側壁部における搬出入口３と干渉する部分を除く前後左右の各側壁部の所要個所に、それぞれ下部ヒータ１１ａ、上部ヒータ１１ｂ、側部ヒータ１１ｃを設けてあり、真空中で熱処理を行う場合には、上記各ヒータ１１ａ，１１ｂ，１１ｃからの輻射により、又、不活性ガス雰囲気下で熱処理を行う場合には、上記各ヒータ１１ａ，１１ｂ，１１ｃからの輻射と、該各ヒータ１１ａ，１１ｂ，１１ｃにて加熱される雰囲気ガスの対流により、上記炉床１０上に熱処理用治具１３ごと載置してある熱処理対象物１２を加熱することができるようにしてある。
【０００８】
したがって、上記熱処理炉にて熱処理対象物１２の熱処理を行う場合には、先ず、本体容器１の扉１ａと、加熱室２の搬出入口３の開閉扉４を共に開放した状態にて、熱処理対象物１２を、熱処理用治具１３に保持させたまま加熱室２内に装入して炉床１０上に載置させ、次いで、加熱室２の搬出入口３の開閉扉４を閉じ、且つ本体容器１の扉１ａを閉じた後、本体容器１の所要位置に接続してある図示しない真空ポンプにて、本体容器１内を真空に引くようにする。その後、真空中で熱処理を行う場合には、このままの状態において、又、不活性ガス雰囲気下で熱処理を行う場合には、上記本体容器１に接続してある図示しない不活性ガス供給部から本体容器１内へ不活性ガスを供給して本体容器１内を不活性ガス雰囲気に置換した状態において、上記各ヒータ１１ａ，１１ｂ，１１ｃのヒータ出力により熱処理対象物１２の加熱を行わせて、該熱処理対象物１２を所望する熱処理温度まで昇温させている。
【０００９】
その後、真空中で熱処理を行っていた場合には、本体容器１内に、上記と同様の不活性ガス供給部から供給される不活性ガス等、所要の雰囲気ガスを導入させた後、図９（イ）（ロ）に二点鎖線で示す如く、加熱室２の冷却扉５ａ，６ａをそれぞれ対応するアクチュエータ５ｂ，６ｂの作動により開放させてから、ファンモータ８により冷却ファン７を回転駆動させる。これにより、本体容器１内の雰囲気ガスを、冷却コイル９にて所要の冷媒と熱交換させて冷却させつつ加熱室２内に循環流通させて、該加熱室２の炉床１０上に熱処理用治具１３に保持された状態で載置されている熱処理対象物１２を所要の冷却速度で冷却させるようにしている。
【００１０】
なお、１４は本体容器１の蓋１ａに設けた覗窓、１５は加熱室２の開閉扉４における上記覗窓１４と対応する位置に設けた開口部、１６は該開口部１５の蓋であり、該蓋１６を本体容器１の外部から所要の操作機構１６ａを介し手動操作して開放させることにより、作業者が、上記覗窓１４と開口部１５を通して、加熱室２内における熱処理対象物の処理状況を観察することができるようにしてある。又、上記熱処理用治具１３は、通常、ＳＵＳ製等の鋼材製とされている。
【００１１】
一方、従来、熱処理時に用いる治具として、電子セラミック素子を焼結、焼成する焼成炉で使用するための焼成治具を、セラミック製の角材と丸棒を組み合わせてラック状に形成した棚板の構成とし、更に、該焼成治具としての棚板の熱容量を小さくし、これにより、焼成炉にて電子セラミック素子の焼結を行うときに、処理品自体の焼結に要する熱量以外に必要とされる焼成治具の加熱に要する熱量の削減を図ることができるようにしたものが提案されている（たとえば、特許文献１参照）。
【００１２】
又、粉末原料の加圧焼結を行うホットプレス装置においては、モールド内に充填した粉末原料の加熱を行う手法として、モールドの外周部に設けたヒータによる輻射及び該ヒータにて加熱される雰囲気ガスの対流によりモールドごと加熱する方式、モールドの外周部に巻いたコイルへ通電することにより、モールド内の粉末原料を誘導加熱する方式、モールド内の粉末原料に通電することにより該粉末原料自体を発熱させるようにする方式、更には、上記ヒータによる加熱と通電加熱を同時に行わせる方式が示されている（たとえば、特許文献２参照）。
【００１３】
【特許文献１】
特開平１１−１７１６５５号公報
【特許文献２】
特開２０００−７３１０６号公報
【００１４】
【発明が解決しようとする課題】
ところが、従来実施されている図９に示す如き、熱処理炉により熱処理対象物１２の加熱を行わせる場合には、上述したように、熱処理対象物１２を、該熱処理対象物１２を保持する熱処理用治具１３ごと加熱室２内に装入し炉床１０上に載置させた状態で、各ヒータ１１ａ，１１ｂ，１１ｃによる加熱を行わせるようにしているが、この場合、上記熱処理用治具１３は、熱処理対象物１２のほぼ１／２から同等、あるいは熱処理対象物１２が軽量の場合には、該熱処理対象物１２以上の重量を占めることがあり、このために大きな熱容量を有していることとなる。
【００１５】
したがって、熱処理用治具１３が存在する側、すなわち、たとえば、トレイ状の熱処理用治具１３の上に載置した熱処理対象物１２を加熱する場合には、上記トレイ状の熱処理用治具１３が存在する下面側では、熱処理対象物１２と一緒に上記トレイ状の熱処理用治具１３をも加熱する必要があり、更には、炉床１０も加熱する必要がある。この場合、熱処理対象物１２全体を均一に加熱するためには、上記トレイ状の熱処理用治具１３や炉床１０が存在するために熱容量が大きくなる下面側の加熱遅れを防止するために、加熱室２の底面部に配されている下部ヒータ１１ａの温度を高くする必要があり、このため該下部ヒータ１１ａのヒータ出力を、上部ヒータ１１ｂや側部ヒータ１１ｃに比して大きく設定しなければならないという問題がある。
【００１６】
又、このように下部ヒータ１１ａの発熱量を大とすると、断熱材製としてある加熱室２の底板が、上部ヒータ１１ｂにより加熱される天井壁や側部ヒータ１１ｃにより加熱される側壁に比して温度が高くなり、このため、加熱室２の底板部分における放熱量が大となる。したがって、熱効率が低下するという問題も懸念される。
【００１７】
なお、上記熱処理用治具１３がバスケット状の場合、該バスケット状の熱処理用治具１３の底板部の存在による熱処理対象物１２の下面側の加熱遅れの防止のために、上記と同様に下部ヒータ１１ａのヒータ出力を高める必要があることに加えて、上記バスケット状の熱処理用治具１３における側壁部の存在による熱処理対象物１２の側面部の加熱遅れを防止するために、側部ヒータ１１ｂのヒータ出力も高める必要が生じる。このため、加熱室２の底板及び側壁の温度が高くなって、これら底板及び側壁からの放熱量が大となり、熱効率がやはり低下することが懸念されるという問題がある。
【００１８】
一方、特許文献１に示された焼成治具のように、上記トレイ状やバスケット状の熱処理用治具１３を、セラミック製の軽量構造とすれば、熱処理用治具１３自体の熱容量を低下させて、該熱処理用治具１３を加熱する必要が生じることとなる下部ヒータ１１ａや側部ヒータ１１ｃのヒータ出力を高める度合が多少緩和できると考えられるが、上記熱処理用治具１３の存在する側、たとえば、底板部や側壁部に臨む下部ヒータ１１ａや側部ヒータ１１ｃのヒータ出力を、熱処理用治具１３に臨まない、たとえば、上部ヒータ１１ｂと同等にすることはできず、上述した問題点を解消するには至らない。
【００１９】
なお、特許文献２に示されたものは、モールドに充填されている粉末原料、すなわち、全周方向を上記モールドに囲まれている粉末原料を加熱対象とする加熱手法に関する技術であるため、上記熱処理炉における熱処理対象物１２の加熱時のように、加熱対象となる熱処理対象物１２の周囲にて熱処理用治具１３の存在する側からの加熱に要する熱量と、熱処理用治具１３が存在しない側からの加熱に要する熱量とで差があることに伴って生じる上述したような問題を解決するために適用できるものではない。
【００２０】
そこで、本発明は、熱処理用治具に保持させた熱処理対象物を熱処理炉にて加熱するときに、該熱処理炉の複数個所にあるヒータの出力の均一化を図ることができると共に、熱効率を高めることができるようにするための熱処理方法及び装置並びに熱処理方法に用いる熱処理炉を提供しようとするものである。
【００２１】
【課題を解決するための手段】
本発明は、上記課題を解決するために、熱処理炉内で熱処理用治具に保持させた熱処理対象物を、ヒータで加熱する熱処理方法において、更に上記熱処理用治具に通電して加熱させ、上記熱処理対象物を加熱することを特徴とする熱処理方法とする。
【００２２】
上記熱処理用治具に通電すると、該熱処理用治具自体は抵抗発熱により昇温させられる。したがって、上記ヒータのヒータ出力により熱処理用治具を加熱する必要がなくなるため、熱処理用治具に臨む側に配置されているヒータであっても、そのヒータ出力は、熱処理対象物の加熱に必要な熱量とすることができ、このために、配置場所の異なる各ヒータ間のヒータ出力差を低減することが可能となる。
【００２３】
熱処理炉内で熱処理対象物を保持させるよう、少なくとも一対のコネクタ部と、該各コネクタ部の間に接続された各コネクタ部よりも電気抵抗値の大きい抵抗発熱部とからなる熱処理用治具を有し、且つ上記各コネクタ部に熱処理炉側に設けてある電極材を接触させて該各コネクタ部間に上記抵抗発熱部を経て通電させることができるようにした構成を有することを特徴とする熱処理用装置とすると、ヒータのヒータ出力差を低減することができることから、加熱室の部分的な温度上昇を抑えることができて放熱量を抑えることができることから、熱効率を高めることができる。
【００２４】
又、昇温する熱処理用治具により熱処理対象物を直接加熱することも可能になるため、従来の如く、ヒータからの輻射、あるいは、ヒータからの輻射とヒータにより加熱された雰囲気ガスの対流のみによって熱処理対象物を間接加熱していた場合に比して、熱処理対象物を加熱する際の熱効率を高めることができて、処理時間の短縮化を図ることも可能になる。
【００２５】
上記熱処理用治具を、所要のトレイ形状の一対向辺部に沿うよう離隔配置した一対のコネクタ部と、上記トレイ形状の面部となる該各コネクタ部の間の領域に上記各コネクタ部の長手方向所要間隔で平行配置した抵抗発熱部とを一体に接続してなる構成とすると、トレイ形状の熱処理用治具を容易に構成することができる。
【００２６】
又、上記において、熱処理用治具のコネクタ部の外側面を粗面加工した構成とすることにより、上記トレイ形状の熱処理用治具におけるコネクタ部も抵抗発熱させることができる。
【００２７】
一方、熱処理用治具を、バスケット形状の外周部における対向する側面部に、少なくとも一対のコネクタ部を露出させて設けると共に、該各コネクタ部間に、上記バスケット形状の側壁部位置及び底板部位置に配置してある抵抗発熱部を一体に接続して、上記対応する各コネクタ部間に、上記バスケット形状の側壁部位置と底板部位置に配置してある抵抗発熱部を経て通電可能な回路を形成できるようにした構成とすることにより、バスケット形状の熱処理用治具を容易に構成することができる。
【００２８】
更に、熱処理用治具の抵抗発熱部における熱処理対象物との接触面部に、酸化性セラミックの溶射皮膜を形成させるようにした構成、又は、熱処理用治具の抵抗発熱部における熱処理対象物との接触面部に、絶縁性を備えた絶縁部材又は上記抵抗発熱部よりも電気抵抗値が大となる高抵抗部材を配置するようにした構成とすることにより、抵抗発熱部よりも電気抵抗が小さい熱処理対象物であっても、上記各熱処理用治具に保持させた状態にて、上記本発明の熱処理方法を実施することができる。
【００２９】
熱処理用治具の抵抗発熱部の素材として、グラファイト材、ニクロム材、タングステン材、モリブデン材、タンタル材、セラミックス材、Ｆｅ−Ｃｒ−Ａｌ系材のうちから選択される一つ又は複数の材質を用いるようにした構成とすることにより、耐熱製と良好な抵抗発熱性を備えた抵抗発熱部を容易に形成できる。
【００３０】
更に又、熱処理炉内で熱処理用治具に保持させた熱処理対象物をヒータで加熱する熱処理方法において、上記熱処理対象物を、該熱処理対象物よりも電気抵抗値の小さい熱処理用治具の間に挟んで保持させて、上記各熱処理用治具の間に上記熱処理対象物を経て通電させて該熱処理対象物を加熱する熱処理方法、及び、目的とする熱処理対象物よりも電気抵抗値が小となる少なくとも１対のコネクタ部材と、対をなす上記各コネクタ部材同士を、熱処理対象物を挟持した状態にて着脱自在に連結する絶縁された連結機構とからなる熱処理用治具を有し、且つ上記熱処理対象物を熱処理炉内で熱処理するときに、上記対をなす各コネクタ部材に熱処理炉側に設けてある電極材を接触させて該各コネクタ部材間に上記熱処理対象物を経て通電させることができるようにした熱処理用装置とすることにより、熱処理炉のヒータ出力により熱処理対象物の加熱を行うときに、熱処理対象物に通電して該熱処理対象物自体を直接昇温させることができるため、各ヒータと熱処理用治具の位置関係に拘らず、上記熱処理対象物をほぼ均一に加熱することができて、熱処理炉のヒータ出力をほぼ均等にすることができることから、上記と同様の効果を得ることができる。
【００３１】
上記の各熱処理用治具の材質を、Ｃ／Ｃコンポジット製とした構成とすることにより、熱処理用治具自体の熱容量を小さくすることができて、該熱処理用治具の加熱に要するエネルギーを削減できると共に、耐クリープ性能を高いものとすることができる。
【００３２】
断熱壁で囲まれた加熱室内にて、該加熱室内底部に設けてある炉床上に熱処理用治具ごと載置した熱処理対象物を、上記加熱室の天井部、内底部及び側壁部にそれぞれ配設したヒータの出力により加熱できるようにしてある熱処理炉における上記加熱室内に、上記炉床上に載置した熱処理用治具に設けてある各コネクタ部に対し接触、離反可能な電極材を備えて、上記各ヒータの出力により熱処理対象物を加熱するときに、上記電極材を上記熱処理用治具のコネクタ部に接触させて該熱処理用治具に通電できるようにした構成を有する熱処理炉とすることにより、熱処理用治具に保持させた熱処理対象物を炉床上に載置してヒータ出力により加熱するときに、上記熱処理用治具に通電して発熱させることができることから上記本発明の熱処理方法を実施するための熱処理炉を容易に構成することができる。
【００３３】
【発明の実施の形態】
以下、本発明の実施の形態を図面を参照して説明する。
【００３４】
図１（イ）（ロ）は本発明の熱処理方法に用いる熱処理用装置における熱処理用治具の実施の一形態としてトレイ状の熱処理用治具に適用した場合を示すものである。本発明で用いる熱処理用治具１７は、耐熱性を有し且つ所要の比抵抗を有する導電性材料として、たとえば、Ｃ／Ｃコンポジット（炭素繊維強化炭素複合材料）製として断面形状縦長の板状に形成した部材を、熱処理対象物１２を載置し保持させるためにトレイ状の熱処理用治具に所望される平面形状の一対向辺部に沿うよう配置して、後述する本発明の熱処理炉に設ける一対の電極材２２を接触できるようにしてある１対のコネクタ部１８と、相対向する該各コネクタ部１８の間に、上記と同様のＣ／Ｃコンポジット製としてある断面形状縦長の板状部材をコネクタ部１８の長手方向と直角方向に且つ所要間隔で平行に配置してなる抵抗発熱部１９とを備え、更に、該各抵抗発熱部１９の両端部を、それぞれ上記左右のコネクタ部１８の内側面に一体に取り付け、又、上記抵抗発熱部１９の所要位置に測温熱電対２０を取り付けた構成としてある。この構成により、上記コネクタ部１８の外側面に、熱処理炉側に設けてある一対の電極材２２をそれぞれ接触させることにより、各コネクタ部１８の間に、上記各抵抗発熱部１９を経て電流を流すことができる回路を形成できるようにしてある。この際、上記コネクタ部１８を板厚方向に流通した電流が、上記各抵抗発熱部１９の長手方向に流れるようになるときに、電流流通方向の断面積が減少することで抵抗が生じるようにし、この抵抗の発生に伴い上記抵抗発熱部１９が抵抗発熱できるようにする。なお、上記熱処理用治具１７の強度を確保するために、図１（イ）（ロ）に示す如く上記各抵抗発熱部１９の長手方向の中間部同士を、Ｃ／Ｃコンポジット製の補強部材２１で一体に連結するようにしてもよい。
【００３５】
次に、図２は本発明の熱処理方法に用いる熱処理炉の実施の一形態を示すもので、図９（イ）（ロ）に示した熱処理炉と同様の構成において、加熱室２内に、一対の電極材２２を備え、且つ該各電極材２２は、加熱室２内の炉床１０上に、図１（イ）（ロ）に示した本発明の熱処理用装置における熱処理用治具１７を、コネクタ部１８が左右に位置するように載置するときに、該トレイ式の熱処理用治具１７の両コネクタ部１８に、着脱自在にそれぞれ接触できるようにしてなる構成としてある。
【００３６】
詳述すると、加熱室２内の炉床１０上に上記熱処理用治具１７を各コネクタ部１８が左右に位置するようにして載置したときに、該各コネクタ部１８と対応する高さ位置となる加熱室２内の炉床１０の左右両側位置に、上記コネクタ部１８の長手方向寸法とほぼ対応して前後方向に延びる電極材２２を配置し、該左右の電極材２２の長手方向中央部の外側面に、それぞれ該電極材２２と直角方向に延び且つ加熱室２の左右の側壁部を摺動自在に貫通するよう配置してある導体製の電極支持部材２３の加熱室内側端部を一体に取り付ける。更に、本体容器１の左右両側部における上記電極支持部材２３の軸心方向の延長線上と対応する所要個所に気密に設けた取付座２４にそれぞれ内向きに取り付けてあるシリンダ２５の作動ロッド２５ａの先端部に、上記各電極支持部材２３の加熱室外側端部を、絶縁部材２６を介在させて一体に連結して、上記各シリンダ２５の作動ロッド２５ａの伸長作動により上記各電極支持部材２３と一体に左右の電極材２２をそれぞれ内向き（炉床１０側）に移動させ、これにより、上記左右の各電極材２２の先端面を、炉床１０上に載置する上記熱処理用治具１７のコネクタ部１８の外側面に面接触させることができるようにしてある。
【００３７】
更に、上記各電極支持部材２３の加熱室外側端部に一端側を接続したフレキシブル電極２７の他端部を、本体容器１の左右両側部における所要位置に気密に設けた取付座２８にそれぞれ内外方向に貫通するよう設置してある各貫通電極材２９の内側端部に接続させるようにする。又、上記各貫通電極材２９の外側端部は、外部の図示しない電力供給部（トランス、サイリスタ等を含む）にそれぞれ接続した構成とする。これにより、上記のように左右のシリンダ２５の伸長作動により各電極材２２を炉床１０上に載置した熱処理用治具１７のコネクタ部１８に接触させるときの各電極支持部材２３と固定側の貫通電極材２９との相対変位を、上記フレキシブル電極２７の変形により吸収できるようにすると共に、上記電力供給部より供給される電力を、貫通電極材２９、フレキシブル電極２７、電極支持部材２３、電極材２２を経て上記熱処理用治具１７のコネクタ部１８に供給できるようにする。
【００３８】
なお、上記各取付座２４に対する対応するシリンダ２５の取付部分や作動ロッド２５ａの貫通部分、及び、各取付座２８に対する対応する貫通電極材２９の貫通部分は、いずれもＯリング等を用いたシール機構を設けて、本体容器１の気密性を保持できるようにしてある。その他の構成は図９（イ）（ロ）に示したものと同様であり、同一のものには同一符号が付してある。
【００３９】
上記構成としてある本発明の熱処理用装置における熱処理用治具１７及び熱処理炉を用いて熱処理対象物１２の熱処理を行う場合は、上記熱処理炉における左右のシリンダ２５の作動ロッド２５ａを収縮作動させて、左右の電極材２２の間隔を、上記熱処理用治具１７の幅よりも広くなるよう配置させておく。
【００４０】
この状態において、上記熱処理用治具１７の上に載置して保持させた該熱処理対象物１２を、従来と同様に、上記熱処理用治具１７ごと熱処理炉の加熱室２内に装入して炉床１０上に載置させる。なお、この際上記熱処理用治具１７は各コネクタ部１８が左右に配されるようにし、且つ該熱処理用治具１７の測温用熱電対２０を、熱処理炉側に設けてある図示しない温度計測装置に接続しておく。次いで、上記各シリンダ２５を伸長作動させて左右の電極材２２を、上記熱処理用治具１７の両コネクタ部１８にそれぞれ接触させる。その後、加熱室２の開閉扉４を閉じると共に、本体容器１の扉を１ａ閉じた後、従来と同様に、必要に応じて本体容器１内を真空、又は、不活性ガス雰囲気に置換し、しかる後、ヒータ１１ａ，１１ｂ，１１ｃによる熱処理対象物１２の加熱を行わせるようにし、同時に、上記電力供給部より、貫通電極材２９、フレキシブル電極２７、電極支持部材２３、電極材２２を経て熱処理用治具１７のコネクタ部１８に、電力を供給し、これにより、該各コネクタ部１８より抵抗発熱部１９に電流を流して該抵抗発熱部１９を炉内温度付近の所定温度まで加熱させるようにする。
【００４１】
上記熱処理用治具１７に通電させて発熱させる場合の制御としては、たとえば、図３（イ）に示す如く、熱処理炉の各ヒータ１１ａ，１１ｂ，１１ｃによって徐々に加熱される炉内温度（線ａ）に対し、上記熱処理用治具１７の測温用熱電対２０により検出される抵抗発熱部温度（線ｂ）がオーバーシュートを生じないように、図３（ロ）に示す如く通電のＯＮ−ＯＦＦ制御を行うようにすればよい。
【００４２】
すなわち、通電ＯＮ時に上記抵抗発熱部１９が炉内温度（線ａ）の昇温速度を上回りそうになるときには、通電をＯＦＦに切換える。このとき上記抵抗発熱部１９が加熱され過ぎた場合には、他の部分よりも放熱量が増えるため、炉内の平均的な温度とみなされる炉内温度（線ａ）で上記抵抗発熱部１９の昇温が停止する。又、上記通電ＯＮ時において、コネクタ部１８は抵抗発熱部１９に比べ抵抗が低いため加熱され難く、したがって、図３（イ）に線ｃで示すコネクタ部温度は、抵抗発熱部温度（線ｂ）に比して低温となっている。したがって、通電ＯＦＦ時には、高温側となる抵抗発熱部１９より、低温側となるコネクタ部１８への熱伝導による熱の移動が生じるため、上記抵抗発熱部１９の過剰な昇温が抑えられると同時に、抵抗発熱部温度（線ｂ）とコネクタ部温度（線ｃ）との温度差が緩和される。
【００４３】
その後、上記抵抗発熱部温度（線ｂ）が炉内温度（線ａ）に比してある程度低くなった場合には、再び通電をＯＮに切換えて抵抗発熱部１９に通電して発熱させて昇温させるようすればよく、上記通電ＯＮと通電ＯＦＦを適宜切替えることにより、熱処理用治具１７全体の温度を、炉内温度（線ａ）に追従させて上昇させるようにすればよい。なお、炉内温度（線ａ）がある程度高温となると、各ヒータ１１ａ，１１ｂ，１１ｃからの輻射伝熱の効果が高まるので、上記熱処理用治具１７への通電はＯＦＦとしたままとしてもかまわない。
【００４４】
このように、上記の方法によれば、熱処理炉の加熱室２内で熱処理対象物１２を加熱するときに、該熱処理対象物１２を保持する熱処理用治具１７自体を抵抗発熱させて炉内温度とほぼ同等となるように加熱することができ、ヒータ出力による加熱と、熱処理用治具１７の抵抗加熱とを併用するハイブリッド加熱を実施できることから、該熱処理用治具１７に臨んで配置されている下部ヒータ１１ａのヒータ出力に関し、上記熱処理用治具１７を加熱するための出力が不要となり、上記下部ヒータ１１ａのヒータ出力を、他のヒータ１１ｂ，１１ｃのヒータ出力とほぼ同等とすることができるため、下部ヒータ１１ａの出力による加熱室２の底板の温度上昇を抑えて放熱量を抑えることができて、熱効率を高めることができる。
【００４５】
なお、上記においては、各ヒータ１１ａ，１１ｂ，１１ｃによる熱処理対象物１２の加熱を行うときに、本発明の熱処理用装置における熱処理用治具１７に対する通電を、熱処理用治具温度が炉内温度を越えないように制御するものとしたが、炉床１０上にセラミックスを置いてその上に熱処理用治具１７を載置させるようにしてある構成において、上記熱処理対象物１２の加熱初期に熱処理用治具温度が炉内温度を多少越えるようにして、この発熱した熱処理用治具１７からの輻射により炉床１０を加熱させるようにしてもよい。このようにすれば、下部ヒータ１１ａのヒータ出力より、従来、炉床１０を加熱するために消費されていた分の熱量も削減できて、該下部ヒータ１１ａのヒータ出力を更に削減して、他のヒータ１１ｂ，１１ｃのヒータ出力と同様に、熱処理対象物１２のみの加熱に必要なヒータ出力とすることができる。
【００４６】
更に、上記いずれの場合にも、熱処理用治具１７に通電して該熱処理用治具１７自体を発熱させると、熱処理用治具１７上に載置し保持されている熱処理対象物１２に対しては、上記発熱した熱処理用治具１７より熱伝導による熱の移動が生じることから、該熱処理対象物１２を直接加熱することも可能となり、したがって、従来の如きヒータ１１ａ，１１ｂ，１１ｃからの輻射、あるいは、該輻射及びヒータ１１ａ，１１ｂ，１１ｃにより加熱された雰囲気ガスの対流によって熱処理対象物１２を間接加熱していた場合に比して、熱処理対象物１２を加熱するための熱効率を高めることができて、処理時間の短縮化を図ることも可能になる。
【００４７】
更に、上記熱処理用治具１７は、Ｃ／Ｃコンポジット製としてあるので、従来のＳＵＳ等の鋼材製としてある熱処理用治具１３と同等の強度を容易に得ることができ、又、上記従来の鋼材製のものに比して大幅な軽量化を図ることができることから、熱容量を小さくできて、該熱処理用治具１７の加熱に要する熱量を削減できることから、省エネルギー化を図ることが可能になり、更には、上記従来の鋼材製のものに比して、クリープに対する耐性を高めることができることから、熱処理用治具としての寿命を延ばすことが可能になる。
【００４８】
上記熱処理炉内にて、熱処理対象物１２を所定温度まで加熱した後、冷却速度を制御しながら冷却することにより該熱処理対象物１２に対する所望の熱処理を施した後は、上記熱処理炉の各シリンダ２５をそれぞれ収縮作動させて、左右の電極材２２を上記熱処理用治具１７のコネクタ部１８の外側面より離隔させた後、従来と同様に上記熱処理用治具１７と一緒に、上記熱処理後の熱処理対象物１２を取り出すようにすればよい。
【００４９】
次に、図４（イ）（ロ）（ハ）は図１（イ）（ロ）に示した本発明の熱処理用治具１７の応用例を示すもので、該熱処理用治具１７では上述したようにコネクタ部１８から抵抗発熱部１９へ電流が流れるときに、該抵抗発熱部１９にて抵抗が増加することで抵抗発熱が生じるようにしてあるため、熱処理用治具１７上に、上記抵抗発熱部１９よりも電気抵抗値が小さい熱処理対象物１２を載置した状態にて、該熱処理用治具１７のコネクタ部１８に熱処理炉側に設けてある電極材２２を接触させて通電させると、熱処理対象物１２自体を経由した回路が形成されてしまい、抵抗発熱部１９の通電量が減少して発熱が阻害される虞が懸念される。よって、このように抵抗発熱部１９よりも電気抵抗値が小さい熱処理対象物１２の熱処理を行う場合には、たとえば、図４（イ）に示す如く、上記熱処理用治具１７の上面側に、耐熱性を有し且つ絶縁性を備えた素材、たとえば、ボロン材等で網状等の所要形状に形成した絶縁部材３０を載置し、その上に熱処理対象物１２を載置して保持させることにより、上記熱処理用治具１７から熱処理対象物１２への通電を上記絶縁部材３０により阻止させるようにすればよい。又、図４（ロ）に示す如く、上記熱処理用治具１７の表面部に露出されて熱処理対象物１２との接触する抵抗発熱部１９や補強部材２０の上下両端面、更には、必要に応じてコネクタ部１８の上下両端面等、熱処理炉側の電極材２２と接触させるコネクタ部１８の外側面を除く所要個所にアルミナ等の酸化性セラミックを溶射して絶縁性と耐熱性を有する溶射皮膜３１を形成させるようにしてもよく、この場合にも、上記と同様に熱処理用治具１７から熱処理対象物１２へ電流が流れることを阻止できる。
【００５０】
更に、熱処理用治具１７から、抵抗発熱部１９よりも電気抵抗値の小さい熱処理対象物１２への通電を防止するための更に他の手法としては、図４（ハ）に示す如く、図４（イ）に示した如き絶縁性を備えた絶縁部材３０に代えて、耐熱性を有し且つ抵抗発熱部１９よりも抵抗値が大となる素材で網状等の所要形状に形成した高抵抗部材３２を、上記熱処理用治具１７と、その上に載置して保持すべき熱処理対象物１２との間に介在させるようにしてもよく、この場合には、電流はより抵抗の少ない経路側へ多く流れる性質があるため、抵抗発熱部１９より上記高抵抗部材３２を経て熱処理対象物１２自体に電流が流れるようになるとしてもその通電量を小さく抑えることができるため、上記抵抗発熱部１９への通電を確保して、該抵抗発熱部１９を抵抗発熱させることができる。
【００５１】
次いで、図５は、本発明の熱処理用装置における熱処理用治具の実施の他の形態を示すもので、図１（イ）（ロ）に示した熱処理用治具１７と同様の構成において、コネクタ部１８の外側面、すなわち、熱処理炉側に設けてある電極材２２との接触面を粗面加工したものである。
【００５２】
その他の構成は図１（イ）（ロ）に示したものと同様であり、同一のものには同一符号が付してある。
【００５３】
本実施の形態によれば、図１（イ）（ロ）に示した熱処理用治具１７と同様に、熱処理用治具１７の上側に熱処理対象物１２を載置して保持させた状態にて、熱処理対象物１２を該熱処理用治具１７と一緒に熱処理炉の炉床１０上に載置した後、熱処理炉側に設けてある各電極材２２を、それぞれ対応するシリンダ２５の伸長駆動により移動させて上記熱処理用治具１７のコネクタ部１８の外側面へ接触させると、該コネクタ部１８の外側面が粗面加工してあるために、コネクタ部１８の外側面と電極材２２は面接触とはならずに多数の点で接触するようになる。このために、上記各電極材２２より熱処理用治具１７のコネクタ部１８へ電力を供給すると、上記コネクタ部１８の外側面と電極材２２との接触部分では電気抵抗値が物性値よりも大きくなり、このため抵抗発熱が生じるようになることから、上記コネクタ部１８を発熱させることができ、このため、上記本発明の熱処理用装置における熱処理用治具１７を、抵抗発熱部１９のみならずコネクタ部１８をも含む全体に亘り発熱させることができる。
【００５４】
なお、上記においては、熱処理用治具１７のコネクタ部１８の外側面を粗面加工するものとして示したが、図６（イ）に示す如く、上記熱処理用治具１７のコネクタ部１８の外側面は平面のままとしておく一方、熱処理炉側に設けてある電極材２２の先端面に粗面加工を施すようにしたり、図６（ロ）に示す如く、熱処理用治具１７のコネクタ部１８の外側面と、熱処理炉側の電極材２２の先端面の双方に粗面加工を施すようにしてもよく、この場合にも上記と同様の効果を得ることができることは明らかである。
【００５５】
更に、図７は本発明の熱処理用装置の実施の更に他の形態として熱処理用治具をバスケット形式とした場合を示すものである。すなわち、バスケット形式とした熱処理用治具３３は、図１（イ）（ロ）に示したトレイ形式の熱処理用治具１７と同様の構成としてあるＣ／Ｃコンポジット製の２つのコネクタ部１８と該各コネクタ部１８間を一体に接続する抵抗発熱部１９とを備えて全体形状を熱処理用治具状としてなる底板部材３４を形成する。更に、上記底板部材３４の形状と対応する四角いリング形状とし且つ各辺部が所要の断面積を備えていて、上下に所要間隔を隔てて平行配置した２つのＣ／Ｃコンポジット製のコネクタ部３６，３７と、該上下の各コネクタ部３６，３７の間に、周方向に所要間隔で多数配置したＣ／Ｃコンポジット製としてある上下方向に延びる板状の抵抗発熱部３８とを有して、該各抵抗発熱部３８の上端部と下端部を、上記上部コネクタ部３６の下面と、下部コネクタ部３７の上面にそれぞれ一体に取り付けることによって、全体形状が角筒型となる周壁部材３５を形成した構成としてある。この構成により、上記上下の各コネクタ部３６，３７に、外部の電源より電力を供給することにより、上下のコネクタ部３６，３７間に上記各抵抗発熱部３８を経て通電可能な回路を形成でき、且つ該回路に通電することにより上記コネクタ部３６，３７を流通した電流が、各抵抗発熱部３８を通過するときに電流の流れる断面積が縮小されて抵抗が高まり、この抵抗により該各抵抗発熱部３８が発熱できるようにしてある。
【００５６】
更に、上記底板部材３４の上側に、上記周壁部材３５を一体に取り付けてバスケット形式の熱処理用治具３３とする。この際、上記底板部材３４の回路と、周壁部材３５の回路をそれぞれ独立した回路とすることができるように、底板部材３４と周壁部材３５を、図示しない耐熱性の絶縁部材を介在させた状態で一体化するか、若しくは、周壁部材と対応する底板部材の外周縁部上面、周壁部材の下端面のいずれか一方又は双方にアルミナの溶射皮膜の如き耐熱性を供え且つ絶縁性を備えた酸化性セラミックの溶射皮膜（図示せず）を形成させた後、底板部材３４と周壁部材３５を一体化させるようにすればよい。
【００５７】
なお、上記熱処理用治具３３に収納して保持させるべき熱処理対象物１２が、電気抵抗値の小さいものの場合には、底板部材３４のコネクタ部１８や抵抗発熱部１９や補強部材２０、周壁部材３５の抵抗発熱部３８やコネクタ部３６，３７の内側面側に、それぞれ図４（イ）（ロ）（ハ）に示したと同様に、絶縁部材３０や高抵抗部材３２を配置したり、絶縁性を備えた溶射皮膜３１を形成させるようにすればよい。
【００５８】
上記本発明の熱処理用装置における熱処理用治具３３に収納して保持させた熱処理対象物１２の熱処理に用いるための熱処理炉としては、図２に示した熱処理炉と同様の構成において、シリンダ２５の伸縮作動により炉床１０上に載置してある熱処理用治具に接触、離反でき且つ外部の電力供給部に接続してある電極材２２を、図７に二点鎖線で示す如く、上記熱処理用治具３３の底板部材３４の各コネクタ部１８に対応した高さ位置となる炉床１０の左右両側位置と、上記周壁部材３５の上部コネクタ部３６に対応した高さにおける炉床１０の一側方位置と、下部コネクタ部３７に対応した高さにおける炉床１０の他側方位置に、それぞれ配設してなる構成として、上記各電極材２２を対応するコネクタ部１８，３６，３７と接触させることにより、底板部材３４と周壁部材３５にそれぞれ抵抗発熱部１９，３８を経て電流を流すことができるようにしてある。
【００５９】
上記図７に示した本発明の熱処理用装置における熱処理用治具３３によれば、熱処理対象物１２を収納、保持させた状態にて炉床１０上に載置した後、図６に二点鎖線で示す如く底板部材３４の各コネクタ部１８と、周壁部材３５の各コネクタ部３６，３７に、それぞれ熱処理炉側に設けてある電極材２２を接触させて、該各電極材２２より、上記底板部材３４と周壁部材３５にそれぞれ通電すると、上記底板部材３４の抵抗発熱部１９が発熱すると共に、周壁部材３５の抵抗発熱部３８が発熱する。したがって、対応する抵抗発熱部１９，３８がそれぞれ発熱することに伴って温度上昇する上記底板部材３４と周壁部材３５のそれぞれの昇温速度を、熱処理炉のヒータ１１ａ，１１ｂ，１１ｃによる熱処理対象物１２の加熱時における炉内温度の昇温速度に対応できるように、底板部材３４及び周壁部材３５への通電を個別にＯＮ−ＯＦＦ制御させるようにすれば、バスケット状の熱処理用治具３３に保持させた熱処理対象物１２を加熱する場合であっても、ヒータ出力による加熱と、熱処理用治具３３自体の抵抗加熱によるハイブリッド加熱を実施でき、このため、上記熱処理用治具３３の底面もしくは側面に臨む下部ヒータ１１ａや側部ヒータ１１ｃのヒータ出力より、熱処理用治具３３自体を加熱させるために従来要求されていた出力を含める必要がなくなるため、これら下部及び側部ヒータ１１ａ，１１ｃのヒータ出力を従来に比して削減できて、図１（イ）（ロ）に示した本発明の熱処理用装置における熱処理用治具１７を用いる場合と同様の効果を得ることができる。
【００６０】
図８（イ）（ロ）（ハ）は本発明の熱処理用装置における熱処理用治具の更に実施の他の形態を示すもので、熱処理対象物として、たとえば、通電による抵抗発熱量等の条件が予め分っている一定（所定）の熱処理対象物１２ａを定常的に熱処理する場合に適したものを対象としたものである。すなわち、耐熱性を備え且つ目的とする熱処理対象物１２ａよりも電気抵抗が小さくなるよう形成した少なくとも２つのコネクタ部材３９と、該各コネクタ部材３９の間に熱処理対象物１２ａを挟んだ状態にて上記各コネクタ部材３９同士を直接導通させることなく着脱自在に連結するための連結機構としてのボルト、ナット機構とを備えてなるものとし、上記各コネクタ部材３９の間に熱処理対象物１２ａを挟持させた状態にて、熱処理炉の炉床１０上に載置して該熱処理炉のヒータ１１ａ，１１ｂ，１１ｃにより上記熱処理対象物１２ａを加熱するときに、上記各コネクタ部材３９に、熱処理炉側に設けてある電極材２２を接続して、上記各コネクタ部材３９より、その間に挟持された熱処理対象物１２ａを経て通電させることにより、上記熱処理対象物１２ａ自体を抵抗発熱させることができるようにしたものである。
【００６１】
詳述すると、上記各コネクタ部材３９は、たとえば、Ｃ／Ｃコンポジット製の矩形の平板状とすると共に、点対称位置より左右方向の一側へややシフトさせた複数個所（図では６個所）に、ボルト孔４０を設けて、左右を反転させたコネクタ部材３９同士を、上記ボルト孔４０位置を一致させて重ね合わせることにより、該各コネクタ部材３９の位置を互いに左右方向にずらすことができるようにしてある。
【００６２】
したがって、上記左右を反転させたコネクタ部材３９同士の間に、たとえば、図８（イ）（ロ）に示す如く立方体状の熱処理対象物１２ａを多数配置し、これを複数段（図８（ロ）では３段）重ねた状態にて、図８（ハ）に示す如く、各コネクタ部材３９のボルト孔４０にＣ／Ｃコンポジット製のボルト４１を挿通させると共に、該ボルト４１の端部に、Ｃ／Ｃコンポジット製のナット４２を螺着させることにより、上記左右方向に位置をずらした各コネクタ部材３９の間にて熱処理対象物を挟持させることができるようにしてあり、この際、上記ボルト４１、ナット４２を介してコネクタ部材３９同士に通電しないようにするために、上記各コネクタ部材３９の各ボルト孔４０の内側には、アルミナ製チューブ４３を嵌挿してその内側に上記ボルト４１を挿通させるようにすると共に、該ボルト４１の先端部にはアルミナ製ワッシャ４４を介してナット４２を螺着させるようにしてある。
【００６３】
本実施の形態の熱処理用治具に保持させた熱処理対象物１２ａを熱処理するための熱処理炉としては、図２に示したと同様の構成としてある熱処理炉において、炉床１０上の熱処理用治具へ接触、離反できるようにしてある電極材２２を、炉床１０上に載置するトレイ状の熱処理用治具１７と対応した高さ位置にて、該熱処理用治具１７のコネクタ部１８の沿って延びる形状とすることに代えて、図８（イ）（ロ）に示す如く、上下方向に延びる形状の電極材２２を備えた構成として、上記した如く間に熱処理対象物１２ａを挟持させることにより対をなす各コネクタ部材３９が互いに左右方向に位置がずれた配置となることに伴って、相対的に左右方向に突出するようになる各コネクタ部材３９の突出端部に、上記電極材２２を接触、離反できるように備えた構成とする。
【００６４】
したがって、上記熱処理対象物１２ａを熱処理する場合は、上記熱処理対象物１２ａを熱処理用治具のコネクタ部材３９に挟持させた状態にて、熱処理炉の炉床１０上に載置した後、図８（イ）（ロ）に二点鎖線で示す如く、上記各コネクタ部材３９に、熱処理炉に設けてある電極材２２を左右方向の対応する側から接触させ、この状態にて、ヒータ１１ａ，１１ｂ，１１ｃによる上記熱処理対象物１２ａの加熱を行うときに、上記各コネクタ部材３９に、熱処理炉側の電極材２２を経て、外部の電力供給装置より電力を供給して、対をなす各コネクタ部材３９の間に、熱処理対象物１２ａを経て通電させるようにし、これにより、各コネクタ部材３９よりも電気抵抗値が大きくなるようにしてある各熱処理対象物１２ａ自体を抵抗発熱させて昇温させるようにする。
【００６５】
このように、本実施の形態によれば、熱処理対象物１２ａ自体を直接昇温させることができるため、熱処理炉の各ヒータ１１ａ，１１ｂ，１１ｃと熱処理用治具の位置関係に拘らず、熱処理対象物１２ａをほぼ均一に加熱することができるため、熱処理炉の各ヒータ１１ａ，１１，１１ｃのヒータ出力をほぼ均等にすると同時に削減できることができることから、上記実施の形態と同様の効果を得ることができる。
【００６６】
なお、本発明は上記実施の形態のみに限定されるものではなく、図１（イ）（ロ）に示した熱処理用治具１７は、トレイ形状の所要個所に設けた少なくとも一対のコネクタ部１８と、該各コネクタ部１８間に接続された抵抗発熱部１９とからトレイ形状を強固に形成できれば、コネクタ部１８及び抵抗発熱部１９とからなる回路の配置は自在に設定してよいこと、図７に示した熱処理用治具３３は、底板部材３４と側壁部材３５を、それぞれ１対のコネクタ部１８，３６，３７と該各コネクタ部１８，３６，３７間に接続された抵抗発熱部１９，３８を備えてなる別々の回路を備えた部材として示したが、底部と側壁部を一つの回路により形成したり、あるいは、各側壁部をそれぞれ別の回路として構成させる等、回路の配置は自在に設定してよいこと、図８（イ）（ロ）（ハ）に示した熱処理用治具では、矩形の平板状のコネクタ部材３９同士の間に、立方体状の熱処理対象物１２ａを挟持させて熱処理を行わせるものとして示したが、目的とする熱処理対象物１２ａを２つのコネクタ部材３９の間に挟持させた状態にて、該各コネクタ部材３９に熱処理炉側に設けてある電極材２２を接触させることにより、該各コネクタ部材３９より熱処理対象物１２ａを経て通電できる回路が形成できるようにすれば、コネクタ部材３９の形状は、上記目的とする熱処理対象物１２ａの形状に対応して自在に設定してよいこと、熱処理炉としては、図１（イ）（ロ）に示した熱処理用治具１７及び図７に示した熱処理用治具３３におけるコネクタ部１８，３６，３７の配置や、図８（イ）（ロ）（ハ）に示した熱処理用治具におけるコネクタ部材３９の配置に対応できるようにすれば、電極材２２の配置は自在に設定してよいこと、又、一室式の熱処理炉以外にも連続処理を行う多室式の熱処理炉にも適用でき、更には、大気条件下にて熱処理を行う熱処理炉に適用してもよいこと、熱処理用治具の素材としてはいずれもＣ／Ｃコンポジット製として示したが、耐熱性を有し且つ所要の電気抵抗を備えた素材であれば、グラファイト材、ニクロム材、タングステン材、モリブデン材、タンタル材、セラミックス材（たとえば、ＳｉＣ）、Ｆｅ−Ｃｒ−Ａｌ系材のうちから選択される一つ又は複数の材質により抵抗発熱部１９，３８を形成してもよく、この場合には、耐熱性と、良好な抵抗発熱性が期待できること、熱処理用治具への通電のＯＮ−ＯＦＦの切換えは、作業者が覗窓１４より加熱室２内における熱処理用治具の加熱状態を目視により判断しながら行うようにしてもよいこと、その他本発明の要旨を逸脱しない範囲内において種々変更を加え得ることは勿論である。
【００６７】
【発明の効果】
以上述べた如く、本発明によれば、以下の如き優れた効果を発揮する。
（１）熱処理炉内で熱処理用治具に保持させた熱処理対象物を、ヒータで加熱する熱処理方法において、更に上記熱処理用治具に通電して加熱させ、上記熱処理対象物を加熱する熱処理方法としてあるので、熱処理対象物を熱処理炉のヒータ出力により加熱するときに、熱処理用治具自体を抵抗発熱により昇温させて上記ヒータ出口と併用させるハイブリッド加熱を行うことができることから、ヒータのヒータ出力により熱処理用治具を加熱する必要をなくすことができて、熱処理用治具に臨む側に配置されているヒータのヒータ出力を削減して他のヒータのヒータ出力とほぼ同等とすることができる。このため、ヒータ出力の相違するヒータが存在することによる熱損失を削減できて、熱効率を高めることができる。
（２）熱処理用治具の昇温により該熱処理用治具に保持されている熱処理対象物を伝熱により直接昇温させることができ、従来の如きヒータからの輻射、あるいは、該輻射及びヒータにより加熱された雰囲気ガスの対流によって熱処理対象物を間接加熱していた場合に比して、熱処理対象物を加熱するための熱効率を高めることができて、処理時間の短縮化を図ることも可能になる。
（３）よって、熱処理炉内で熱処理対象物を保持させるよう、少なくとも一対のコネクタ部と、該各コネクタ部の間に接続された各コネクタ部よりも電気抵抗値の大きい抵抗発熱部とからなる熱処理用治具を有し、且つ上記各コネクタ部に熱処理炉側に設けてある電極材を接触させて該各コネクタ部間に上記抵抗発熱部を経て通電させることができるようにした構成を有する熱処理用装置と、断熱壁で囲まれた加熱室内にて、該加熱室内底部に設けてある炉床上に熱処理用治具ごと載置した熱処理対象物を、上記加熱室の天井部、内底部及び側壁部にそれぞれ配設したヒータの出力により加熱できるようにしてある熱処理炉における上記加熱室内に、上記炉床上に載置した熱処理用治具に設けてある各コネクタ部に対し接触、離反可能な電極材を備えて、上記各ヒータの出力により熱処理対象物を加熱するときに、上記電極材を上記熱処理用治具のコネクタ部に接触させて該熱処理用治具に通電できるようにした熱処理炉を用いることにより、上記方法を実施することができ、このため、ヒータのヒータ出力の均一化を図ることができることから、加熱室の部分的な温度上昇を抑えることができて放熱量を抑えることができることから、熱効率を高めることができる。
（４）上記（３）のほかに、昇温する熱処理用治具により熱処理対象物を直接加熱することも可能になるため、従来の如く、ヒータからの輻射、あるいは、ヒータからの輻射とヒータにより加熱された雰囲気ガスの対流のみによって熱処理対象物を間接加熱していた場合に比して、熱処理対象物を加熱する際の熱効率を高めることができて、処理時間の短縮化を図ることも可能になる。
（５）熱処理用治具を、所要のトレイ形状の一対向辺部に沿うよう離隔配置した一対のコネクタ部と、上記トレイ形状の面部となる該各コネクタ部の間の領域に上記各コネクタ部の長手方向所要間隔で平行配置した抵抗発熱部とを一体に接続してなる構成とすると、トレイ形状の熱処理用治具を容易に構成することができる。
（６）又、熱処理用治具のコネクタ部の外側面を粗面加工した構成とすることにより、上記トレイ形状の熱処理用治具におけるコネクタ部も抵抗発熱させることができる。
（７）熱処理用治具を、バスケット形状の外周部における対向する側面部に、少なくとも一対のコネクタ部を露出させて設けると共に、該各コネクタ部間に、上記バスケット形状の側壁部位置及び底板部位置に配置してある抵抗発熱部を一体に接続して、上記対応する各コネクタ部間に、上記バスケット形状の側壁部位置と底板部位置に配置してある抵抗発熱部を経て通電可能な回路を形成できるようにした構成とすることにより、バスケット形状の熱処理用治具を容易に構成することができる。
（８）更に、熱処理用治具の抵抗発熱部における熱処理対象物との接触面部に、酸化性セラミックの溶射皮膜を形成させるようにした構成、又は、熱処理用治具の抵抗発熱部における熱処理対象物との接触面部に、絶縁性を備えた絶縁部材又は上記抵抗発熱部よりも電気抵抗値が大となる高抵抗部材を配置するようにした構成とすることにより、抵抗発熱部よりも電気抵抗が小さい熱処理対象物であっても、上記各熱処理用治具に保持させた状態にて、上記本発明の熱処理方法を実施することができる。
（９）上記において、熱処理用治具の抵抗発熱部の素材として、グラファイト材、ニクロム材、タングステン材、モリブデン材、タンタル材、セラミックス材（たとえば、ＳｉＣ）、Ｆｅ−Ｃｒ−Ａｌ系材のうちから選択される一つ又は複数の材質を用いるようにした構成とすることにより、耐熱製と良好な抵抗発熱性を備えた抵抗発熱部を容易に形成できる。
（１０）更に又、熱処理炉内で熱処理用治具に保持させた熱処理対象物をヒータで加熱する熱処理方法において、上記熱処理対象物を、該熱処理対象物よりも電気抵抗値の小さい熱処理用治具の間に挟んで保持させて、上記各熱処理用治具の間に上記熱処理対象物を経て通電させて該熱処理対象物を加熱することを特徴とする熱処理方法、及び、目的とする熱処理対象物よりも電気抵抗値が小となる少なくとも１対のコネクタ部材と、対をなす上記各コネクタ部材同士を、熱処理対象物を挟持した状態にて着脱自在に連結する絶縁された連結機構とからなる熱処理用治具を有し、且つ上記熱処理対象物を熱処理炉内で熱処理するときに、上記対をなす各コネクタ部材に熱処理炉側に設けてある電極材を接触させて該各コネクタ部材間に上記熱処理対象物を経て通電させることができるようにした熱処理用装置とすることにより、熱処理炉のヒータ出力により熱処理対象物の加熱を行うときに、熱処理対象物に通電して該熱処理対象物自体を直接昇温させることができるため、各ヒータと熱処理用治具の位置関係に拘らず、上記熱処理対象物をほぼ均一に加熱することができて、熱処理炉のヒータ出力をほぼ均等にすることができることから、上記と同様の効果を得ることができる。
（１１）上記の各熱処理用治具の材質を、Ｃ／Ｃコンポジット製とした構成とすることにより、熱処理用治具自体の熱容量を小さくすることができて、該熱処理用治具の加熱に要するエネルギーを削減できると共に、耐クリープ性能を高いものとすることができる。
【図面の簡単な説明】
【図１】本発明の熱処理用装置の実施の一形態として熱処理用治具をトレイ形状としたものを示すもので、（イ）は概略正面図、（ロ）は概略平面図を示すものである。
【図２】本発明の熱処理炉の実施の一形態を示すもので、概略切断正面図を示すものである。
【図３】図２の熱処理炉における、図１に示した熱処理用治具への通電の制御方法を示すもので、（イ）は炉内温度と、熱処理用治具の抵抗発熱部温度及びコネクタ部温度の温度変化を示す図で、（ロ）は熱処理用治具への通電のＯＮ−ＯＦＦの切換え操作のタイミングを示す図である。
【図４】図１の熱処理用治具にて、該熱処理用治具の抵抗発熱部よりも電気抵抗値の小さい熱処理対象物への通電を防止するための対応策を示すもので、（イ）は熱処理用治具と熱処理対象物との間に絶縁部材を介在させるようにした状態を、（ロ）は熱処理用治具の表面部に絶縁性の溶射皮膜を形成した状態を、（ハ）は熱処理用治具と熱処理対象物との間に高抵抗部材を介在させるようにした状態をそれぞれ示す概略正面図である。
【図５】本発明の熱処理用装置の実施の他の形態を示すもので、コネクタ部を拡大して示す図である。
【図６】熱処理用治具のコネクタ部を発熱させるための手段を示すもので、（イ）は熱処理炉側の電極材の先端面を粗面加工した状態を、（ロ）は熱処理用治具のコネクタ部の外側面と、熱処理炉側の電極材の先端面を共に粗面加工した状態をそれぞれ示す要部拡大図である。
【図７】本発明の熱処理用装置の実施の更に他の形態として熱処理用治具をバスケット形状にしたものを示す概略斜視図である。
【図８】本発明の熱処理用装置の実施の更に他の形態を示すもので、（イ）は概略平面図、（ロ）は概略正面図、（ハ）はボルトの先端部付近を拡大して示す図である。
【図９】従来一般に用いられている熱処理炉の一例の概略を示すもので、（イ）は切断側面図、（ロ）は切断正面図を示すものである。
【符号の説明】
２加熱室
１０炉床
１１ａ，１１ｂ，１１ｃヒータ
１２熱処理対象物
１７熱処理用治具
１８コネクタ部
１９抵抗発熱部
２２電極材
３０絶縁部材
３１溶射皮膜
３２高抵抗部材
３３熱処理用治具
３４底板部材（底板部）
３５周壁部材（側壁部）
３６上部コネクタ部（コネクタ部）
３７下部コネクタ部（コネクタ部）
３８抵抗発熱部
３９コネクタ部材
４１ボルト（連結機構）
４２ナット（連結機構）[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention is a heat treatment method and apparatus used when quenching, tempering, annealing, heat treatment such as normalizing and sintering of ceramics, magnetic materials, carbon materials, and composite materials, and the like for sintering steel materials. The present invention relates to a heat treatment furnace used for a heat treatment method.
[0002]
[Prior art]
Steel materials such as metal and alloy members and products may be subjected to various heat treatments such as quenching, tempering, and annealing in order to change hardness, strength, toughness, and other mechanical properties. When such a heat treatment is performed, usually, in a heat treatment furnace, the object to be heat treated is heated to a required high temperature condition, for example, 700 to 1400 ° C., and further heated to about 2000 ° C. depending on the material, and then cooled. In addition, various heat treatment effects can be obtained by controlling the heating temperature and the cooling rate during cooling.
[0003]
Also, when sintering and firing ceramics, magnetic materials, carbon materials, composite materials, etc., heat treatment at a high temperature may be required.
[0004]
When performing the various heat treatments as described above, the heat treatment may be performed in a controlled atmosphere such as a vacuum or an inert gas atmosphere.
[0005]
FIGS. 9 (a) and 9 (b) show a one-chamber type heat treatment furnace for performing a batch process as an example of a heat treatment furnace for performing heat treatment in a vacuum or under an inert gas atmosphere as described above. And has the following configuration. That is, a box-shaped heating chamber 2 surrounded by a heat insulating wall is provided at the center of a main body container 1 capable of holding an internal atmosphere such as a vacuum or an inert gas atmosphere with an openable and closable door 1a at the front. The heating chamber 2 has a front side wall provided with a loading / unloading port 3 for the object to be processed which can be opened and closed by an opening / closing door 4, and a ceiling wall and a bottom plate provided with gas circulation openings 5 and 6. Further, the cooling doors 5a and 6a are opened and closed by the actuators 5b and 6b, respectively. A cooling fan 7 is attached to an output shaft of a fan motor 8 installed inward at the top of the main body container 1 above the upper opening 5, and a cooling fan 7 is provided at an upper position inside the main body container 1 from outside. The cooling fan 9 is rotated by the fan motor 8 in a state where the cooling doors 5a and 6a of the respective openings 5 and 6 are opened by providing the cooling coil 9 through which the refrigerant of the first embodiment can flow. By driving, the ambient gas in the main body container 1 can be circulated and circulated into the heating chamber 2 through the openings 5 and 6 while being cooled by the cooling coil 9.
[0006]
A hearth 10 is provided at a lower position in the heating chamber 2, and a tray-like heat treatment jig 13 inserted into the heating chamber 2 through the carry-in / out port 3 is provided on the hearth 10. Alternatively, a basket-shaped heat treatment jig 13 is placed (in the figure, a tray-shaped heat treatment jig 13 is placed).
[0007]
Further, in the heating chamber 2, at least four directions surrounding the object to be heat-treated mounted on the hearth 10, that is, a required portion which does not interfere with the hearth 10 in the inner bottom, a ceiling, A lower heater 11a, an upper heater 11b, and a side heater 11c are provided at required portions of the front, rear, left, and right side walls except for a portion that interferes with the carry-in / out entrance 3 in the side wall. When heat treatment is performed by the radiation from the heaters 11a, 11b, and 11c or in an inert gas atmosphere, the radiation from the heaters 11a, 11b, and 11c and the heaters 11a, 11b, and 11c The heat treatment object 12 placed together with the heat treatment jig 13 on the hearth 10 can be heated by the convection of the atmosphere gas heated by the heat treatment.
[0008]
Therefore, when the heat treatment of the heat treatment object 12 is performed in the heat treatment furnace, first, the heat treatment object 12 is opened in a state where the door 1 a of the main body container 1 and the opening / closing door 4 of the carry-in / out entrance 3 of the heating chamber 2 are both opened. The object 12 is loaded into the heating chamber 2 while being held by the jig 13 for heat treatment, and placed on the hearth 10. Then, the opening / closing door 4 of the entrance 3 of the heating chamber 2 is closed, and After closing the door 1a of the container 1, the inside of the main container 1 is evacuated by a vacuum pump (not shown) connected to a required position of the main container 1. Thereafter, when heat treatment is performed in a vacuum, the heat treatment is performed as it is, and when heat treatment is performed in an inert gas atmosphere, the heat is supplied from an inert gas supply unit (not shown) connected to the main body container 1. In a state in which an inert gas is supplied into the container 1 and the inside of the main container 1 is replaced with an inert gas atmosphere, the heat treatment target 12 is heated by the heater outputs of the heaters 11a, 11b, and 11c. The heat treatment target 12 is heated to a desired heat treatment temperature.
[0009]
After that, when the heat treatment is performed in a vacuum, a required atmosphere gas such as an inert gas supplied from the same inert gas supply unit as described above is introduced into the main body container 1 and then, as shown in FIG. (A) As shown by the two-dot chain line in (B), the cooling doors 5a, 6a of the heating chamber 2 are opened by the operation of the corresponding actuators 5b, 6b, and then the cooling fan 7 is rotationally driven by the fan motor 8. . Thereby, the atmosphere gas in the main body container 1 is circulated and circulated in the heating chamber 2 while being cooled by exchanging heat with a required refrigerant in the cooling coil 9, and is placed on the hearth 10 of the heating chamber 2 for heat treatment. The heat treatment target 12 placed in a state held by the jig 13 is cooled at a required cooling rate.
[0010]
In addition, 14 is a viewing window provided in the lid 1a of the main body container 1, 15 is an opening provided in the opening / closing door 4 of the heating chamber 2 at a position corresponding to the viewing window 14, and 16 is a lid of the opening 15. By manually opening the lid 16 from the outside of the main body container 1 via a required operation mechanism 16a, the operator can open the lid 16 through the viewing window 14 and the opening 15 so that the heat treatment target in the heating chamber 2 can be opened. The processing status can be observed. The heat treatment jig 13 is usually made of steel such as SUS.
[0011]
On the other hand, conventionally, as a jig used at the time of heat treatment, a firing jig for use in a firing furnace for sintering and firing an electronic ceramic element is a shelf plate formed by combining a ceramic square material and a round bar into a rack shape. In addition, the heat capacity of the shelf plate as the firing jig is reduced, so that when sintering the electronic ceramic element in the firing furnace, it is necessary to reduce the amount of heat required for sintering the processed product itself. There has been proposed a device capable of reducing the amount of heat required for heating a firing jig (for example, see Patent Document 1).
[0012]
Further, in a hot press apparatus for sintering powder raw materials under pressure, as a method of heating the powder raw materials filled in the mold, radiation from a heater provided on an outer peripheral portion of the mold and an atmosphere heated by the heater are used. A method of heating the entire mold by convection of gas, a method of inductively heating the powder material in the mold by energizing a coil wound around the outer periphery of the mold, and a method of energizing the powder material in the mold to energize the powder material itself. A method of generating heat, and a method of simultaneously performing heating by the heater and energization heating are disclosed (for example, see Patent Document 2).
[0013]
[Patent Document 1]
JP-A-11-171655
[Patent Document 2]
JP-A-2000-73106
[0014]
[Problems to be solved by the invention]
However, when the heat treatment target 12 is heated by a heat treatment furnace as shown in FIG. 9, which is conventionally performed, as described above, the heat treatment target 12 is replaced with a heat treatment target holding the heat treatment target 12. Heating is performed by the heaters 11a, 11b, and 11c in a state in which the jig 13 is placed in the heating chamber 2 and placed on the hearth 10. In this case, the heat treatment jig is used. The heat treatment object 13 may occupy more than half the heat treatment object 12 or may occupy more than the heat treatment object 12 when the heat treatment object 12 is lightweight, and therefore has a large heat capacity. Will be.
[0015]
Therefore, when heating the heat treatment target 12 placed on the side where the heat treatment jig 13 is present, that is, for example, on the tray-shaped heat treatment jig 13, the tray-shaped heat treatment jig 13 is heated. It is necessary to heat the tray-shaped heat treatment jig 13 together with the heat treatment object 12 on the lower surface side where the heat sink exists, and it is also necessary to heat the hearth 10. In this case, in order to uniformly heat the entire heat treatment target 12, in order to prevent a heating delay on the lower surface side where the heat capacity increases due to the presence of the tray-shaped heat treatment jig 13 and the hearth 10, It is necessary to increase the temperature of the lower heater 11a disposed on the bottom surface of the heating chamber 2. Therefore, the heater output of the lower heater 11a must be set higher than that of the upper heater 11b and the side heater 11c. There is a problem that must be.
[0016]
Further, when the calorific value of the lower heater 11a is increased as described above, the bottom plate of the heating chamber 2 made of heat insulating material is compared with the ceiling wall heated by the upper heater 11b and the side wall heated by the side heater 11c. As a result, the temperature increases, and the amount of heat radiation at the bottom plate portion of the heating chamber 2 increases. Therefore, there is a concern that the thermal efficiency is reduced.
[0017]
When the heat treatment jig 13 is in the form of a basket, in order to prevent a heating delay on the lower surface side of the heat treatment target 12 due to the presence of the bottom plate portion of the basket heat treatment jig 13, the lower part is formed in the same manner as described above. In addition to the need to increase the heater output of the heater 11a, the side heater 11b is used to prevent a delay in heating the side surface of the heat treatment target 12 due to the presence of the side wall in the basket-like heat treatment jig 13. Needs to be increased. For this reason, there is a problem that the temperature of the bottom plate and the side wall of the heating chamber 2 becomes high, the amount of heat radiated from the bottom plate and the side wall becomes large, and there is a concern that the thermal efficiency is also lowered.
[0018]
On the other hand, if the tray-shaped or basket-shaped heat treatment jig 13 is made of a lightweight ceramic structure like the firing jig shown in Patent Document 1, the heat capacity of the heat treatment jig 13 itself is reduced. Thus, it is considered that the degree to which the heater output of the lower heater 11a and the side heater 11c that would require the heating jig 13 to be heated can be alleviated somewhat. For example, the heater output of the lower heater 11a or the side heater 11c facing the bottom plate or the side wall cannot be made equal to that of the upper heater 11b that does not face the heat treatment jig 13, for example. Can not be resolved.
[0019]
The technique disclosed in Patent Document 2 relates to a heating technique in which a powder raw material filled in a mold, that is, a powder raw material surrounded by the mold in the entire circumferential direction is a heating target. As in the case of heating the heat treatment target 12 in the heat treatment furnace, the amount of heat required for heating from the side where the heat treatment jig 13 is present around the heat treatment target 12 to be heated and the heat treatment jig 13 It cannot be applied to solve the above-described problem caused by the difference in the amount of heat required for heating from the side not to be heated.
[0020]
Therefore, the present invention can equalize the output of the heaters at a plurality of locations in the heat treatment furnace when heating the heat treatment target held by the heat treatment jig in the heat treatment furnace, and improve the thermal efficiency. An object of the present invention is to provide a heat treatment method and apparatus for increasing the temperature and a heat treatment furnace used for the heat treatment method.
[0021]
[Means for Solving the Problems]
The present invention, in order to solve the above-described problems, in a heat treatment method of heating a heat treatment target held in a heat treatment jig in a heat treatment furnace by a heater, further energizing and heating the heat treatment jig, A heat treatment method is characterized in that the heat treatment target is heated.
[0022]
When the heat treatment jig is energized, the heat treatment jig itself is heated by resistance heating. Therefore, since it is not necessary to heat the heat treatment jig by the heater output of the heater, even if the heater is disposed on the side facing the heat treatment jig, the heater output is necessary for heating the heat treatment target. Therefore, it is possible to reduce the difference in heater output between the heaters at different locations.
[0023]
A heat treatment jig including at least a pair of connector portions and a resistance heating portion having a higher electric resistance value than each connector portion connected between the connector portions so as to hold the heat treatment target in the heat treatment furnace. And a structure in which an electrode material provided on the heat treatment furnace side is brought into contact with each of the connector portions so that current can flow between the respective connector portions through the resistance heating portion. When the heat treatment apparatus is used, the difference in heater output between the heaters can be reduced, so that a partial rise in temperature in the heating chamber can be suppressed and the amount of heat radiation can be suppressed, so that thermal efficiency can be increased.
[0024]
In addition, since it is possible to directly heat the object to be heat-treated by the heat-treating jig that raises the temperature, only the radiation from the heater or the radiation from the heater and the convection of the atmosphere gas heated by the heater are required. As compared with the case where the object to be heat-treated is heated indirectly, the thermal efficiency when heating the object to be heat-treated can be increased, and the processing time can be shortened.
[0025]
The heat treatment jig is disposed in a region between the pair of connector portions spaced apart along one opposing side of the required tray shape and the respective connector portions serving as the tray-shaped surface portions. If the resistance heating portions arranged in parallel in the required direction are integrally connected, a tray-shaped heat treatment jig can be easily formed.
[0026]
Further, in the above, by forming the outer surface of the connector portion of the heat treatment jig into a roughened surface, the connector portion of the tray-shaped heat treatment jig can also generate resistance heat.
[0027]
On the other hand, a jig for heat treatment is provided on at least a pair of exposed connector portions on opposed side portions of the outer peripheral portion of the basket shape, and between the respective connector portions, the position of the side wall portion and the bottom plate portion of the basket shape are set. A circuit that can be energized through the resistance heating portions disposed integrally at the basket-shaped side wall portion position and the bottom plate portion position between the corresponding connector portions by integrally connecting the resistance heating portions arranged at By adopting a configuration in which it can be formed, a basket-shaped heat treatment jig can be easily configured.
[0028]
Further, a configuration in which a thermal spray coating of an oxidizable ceramic is formed on a contact surface portion of the resistance heating portion of the heat treatment jig with the heat treatment target, or a configuration in which the heat treatment target of the resistance heat generation portion of the heat treatment jig is formed. A heat treatment having an electric resistance smaller than that of the resistance heating portion is provided by disposing an insulating member having an insulating property or a high resistance member having an electric resistance value larger than that of the resistance heating portion on the contact surface portion. The heat treatment method of the present invention can be performed in a state where the object is held by the heat treatment jigs.
[0029]
One or more materials selected from graphite, nichrome, tungsten, molybdenum, tantalum, ceramics, and Fe-Cr-Al-based materials are used as the material of the resistance heating portion of the heat treatment jig. By adopting such a configuration, it is possible to easily form a resistance heating portion having heat resistance and good resistance to heat generation.
[0030]
Further, in the heat treatment method of heating a heat treatment object held by the heat treatment jig in the heat treatment furnace with a heater, the heat treatment object is interposed between the heat treatment jigs having a smaller electric resistance value than the heat treatment object. A heat treatment method of heating the heat treatment object by passing current through the heat treatment object between the heat treatment jigs, and an electric resistance value smaller than that of the target heat treatment object. At least one pair of connector members and a heat treatment jig comprising an insulated connection mechanism for detachably connecting the pair of connector members to each other while sandwiching the object to be heat treated, And when the object to be heat-treated is heat-treated in a heat-treating furnace, an electrode material provided on the heat-treating furnace side is brought into contact with each of the paired connector members, and electricity is passed between the connector members through the object to be heat-treated. With the heat treatment apparatus configured to be able to perform the heat treatment, when the heat treatment target is heated by the heater output of the heat treatment furnace, the heat treatment target can be energized to directly raise the temperature of the heat treatment target itself. Therefore, regardless of the positional relationship between each heater and the jig for heat treatment, the object to be heat-treated can be heated substantially uniformly, and the heater output of the heat treatment furnace can be made substantially uniform. The effect can be obtained.
[0031]
The heat capacity of the heat treatment jig itself can be reduced by making the heat treatment jig made of a C / C composite material, and the energy required for heating the heat treatment jig can be reduced. In addition to the reduction, the creep resistance can be improved.
[0032]
In a heating chamber surrounded by heat insulating walls, heat treatment objects placed together with heat treatment jigs on a hearth provided at the bottom of the heating chamber are arranged on the ceiling, inner bottom, and side walls of the heating chamber. In the heating chamber of the heat treatment furnace which can be heated by the output of the heater provided, an electrode material capable of coming into contact with and detaching from each connector provided on the heat treatment jig placed on the hearth is provided. When the object to be heat-treated is heated by the output of each of the heaters, the electrode material is brought into contact with a connector portion of the heat-treatment jig so that the heat-treatment jig can be energized. Thereby, when the object to be heat-treated held by the heat-treating jig is placed on the hearth and heated by the heater output, the heat-treating jig can be energized to generate heat. The heat treatment furnace for carrying out the law can be easily constructed.
[0033]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0034]
FIGS. 1A and 1B show an embodiment of a heat treatment jig in a heat treatment apparatus used in the heat treatment method of the present invention, which is applied to a tray-like heat treatment jig. The heat treatment jig 17 used in the present invention is made of a C / C composite (carbon fiber reinforced carbon composite material) made of a conductive material having heat resistance and a required specific resistance. The heat treatment furnace of the present invention to be described later is arranged such that the member formed in the above-described manner is arranged along one opposite side portion of a planar shape desired for a tray-like heat treatment jig for mounting and holding the heat treatment object 12. A pair of connector portions 18 provided so as to allow a pair of electrode members 22 provided to contact each other, and between each of the opposing connector portions 18, a vertically elongated plate made of the same C / C composite as described above. And a resistance heating section 19 in which the shape-like members are arranged in a direction perpendicular to the longitudinal direction of the connector section 18 and in parallel at required intervals, and further, both ends of each of the resistance heating sections 19 are respectively connected to the left and right connector sections. Of 18 Integrally attached to the surface, also it is constituted fitted with temperature thermocouple 20 measure the required position of the resistance heating portion 19. With this configuration, a pair of electrode members 22 provided on the heat treatment furnace side are brought into contact with the outer surface of the connector section 18 respectively, so that a current is passed between the connector sections 18 via the resistance heating sections 19. A circuit that can flow can be formed. At this time, when the current flowing in the thickness direction of the connector portion 18 flows in the longitudinal direction of each of the resistance heating portions 19, resistance is generated by reducing the cross-sectional area in the current flowing direction. With the generation of the resistance, the resistance heating portion 19 is configured to generate the resistance. In order to ensure the strength of the heat treatment jig 17, as shown in FIGS. 1A and 2B, the longitudinal intermediate portions of the resistance heating portions 19 are connected to each other by a reinforcing member made of a C / C composite. 21 may be integrally connected.
[0035]
Next, FIG. 2 shows an embodiment of a heat treatment furnace used in the heat treatment method of the present invention. In the same configuration as the heat treatment furnace shown in FIGS. A pair of electrode members 22 are provided, and each of the electrode members 22 is placed on the hearth 10 in the heating chamber 2 on the heat treatment jig 17 in the heat treatment apparatus of the present invention shown in FIGS. When the connector 18 is placed so that the connector portions 18 are located on the left and right, the tray type heat treatment jig 17 can be detachably contacted with both connector portions 18 respectively.
[0036]
More specifically, when the heat treatment jig 17 is placed on the hearth 10 in the heating chamber 2 such that the connector portions 18 are located on the left and right, the height positions corresponding to the respective connector portions 18 are set. An electrode member 22 extending in the front-rear direction substantially corresponding to the longitudinal dimension of the connector portion 18 is disposed at both left and right positions of the hearth 10 in the heating chamber 2 to be heated. The inner end of the electrode support member 23 made of a conductor, which extends in a direction perpendicular to the electrode material 22 and slidably penetrates the left and right side walls of the heating chamber 2 on the outer surface of the heating chamber 2. Are attached together. Further, the operating rods 25a of the cylinders 25 which are inwardly mounted on the mounting seats 24 which are provided airtightly at required locations corresponding to the axial extension of the electrode support member 23 on both the left and right sides of the main body container 1 respectively. The end of the heating chamber outside of each of the electrode support members 23 is integrally connected to the distal end with an insulating member 26 interposed therebetween, and the respective electrode support members 23 are connected to each other by the extension operation of the operation rod 25a of each of the cylinders 25. The left and right electrode members 22 are integrally moved inward (toward the hearth 10), whereby the tip surfaces of the left and right electrode members 22 are placed on the hearth 10 by the heat treatment jig 17. The connector portion 18 can be brought into surface contact with the outer surface.
[0037]
Further, the other end of the flexible electrode 27 whose one end is connected to the outer end of the heating chamber of each of the electrode support members 23 is connected to the inside and outside of the mounting seat 28 which is provided at a required position on the right and left sides of the main body container 1 at a required position. Each of the through-electrode members 29 installed so as to penetrate in the direction is connected to the inner end portion. The outer end of each through electrode material 29 is connected to an external power supply (not shown) (including a transformer, a thyristor, and the like). As a result, when the electrode materials 22 are brought into contact with the connector portion 18 of the heat treatment jig 17 placed on the hearth 10 by the extension operation of the left and right cylinders 25 as described above, each electrode support member 23 and the fixed side are fixed. Relative to the through electrode material 29 can be absorbed by the deformation of the flexible electrode 27, and the electric power supplied from the power supply unit is supplied to the through electrode material 29, the flexible electrode 27, the electrode support member 23, It can be supplied to the connector 18 of the heat treatment jig 17 via the electrode material 22.
[0038]
The mounting portion of the cylinder 25 corresponding to each mounting seat 24 and the penetrating portion of the operating rod 25a and the penetrating portion of the corresponding penetrating electrode material 29 for each mounting seat 28 are all sealed using an O-ring or the like. A mechanism is provided so that the airtightness of the main body container 1 can be maintained. Other configurations are the same as those shown in FIGS. 9A and 9B, and the same components are denoted by the same reference numerals.
[0039]
When the heat treatment of the heat treatment target 12 is performed using the heat treatment jig 17 and the heat treatment furnace in the heat treatment apparatus of the present invention having the above-described configuration, the operation rods 25a of the left and right cylinders 25 in the heat treatment furnace are contracted. The distance between the left and right electrode members 22 is arranged to be wider than the width of the heat treatment jig 17.
[0040]
In this state, the heat treatment target 12 placed and held on the heat treatment jig 17 is charged into the heating chamber 2 of the heat treatment furnace together with the heat treatment jig 17 as in the related art. And placed on the hearth 10. At this time, the heat treatment jig 17 is arranged such that the connector portions 18 are arranged on the left and right, and the temperature measuring thermocouple 20 of the heat treatment jig 17 is provided at a heat treatment furnace side (not shown). Connect to the measuring device. Then, the cylinders 25 are extended to bring the left and right electrode members 22 into contact with both connector portions 18 of the heat treatment jig 17, respectively. Thereafter, the opening / closing door 4 of the heating chamber 2 is closed, and the door of the main body container 1 is closed 1a. Then, as in the related art, the inside of the main body container 1 is replaced with a vacuum or an inert gas atmosphere as necessary, Thereafter, the heat treatment target 12 is heated by the heaters 11a, 11b, and 11c, and at the same time, heat treatment is performed by the power supply unit through the through electrode material 29, the flexible electrode 27, the electrode support member 23, and the electrode material 22. Electric power is supplied to the connector section 18 of the tool jig 17 so that current flows from each connector section 18 to the resistance heating section 19 to heat the resistance heating section 19 to a predetermined temperature near the furnace temperature. To
[0041]
For example, as shown in FIG. 3 (a), the control for energizing the heat treatment jig 17 to generate heat includes, as shown in FIG. 3 (a), a furnace temperature (line) which is gradually heated by the heaters 11a, 11b, 11c of the heat treatment furnace. On the other hand, as shown in FIG. 3B, the energization is turned on as shown in FIG. 3B so that the resistance heating portion temperature (line b) detected by the temperature measuring thermocouple 20 of the heat treatment jig 17 does not overshoot. What is necessary is just to perform -OFF control.
[0042]
That is, if the resistance heating section 19 is likely to exceed the rate of temperature increase of the furnace temperature (line a) when energization is ON, energization is switched off. At this time, if the resistance heating section 19 is excessively heated, the amount of heat radiation increases more than in other parts, so that the resistance heating section 19 is heated at a furnace temperature (line a) regarded as an average temperature in the furnace. The temperature rise stops. In addition, when the power supply is ON, the connector 18 has a lower resistance than the resistance heating section 19 and is therefore difficult to be heated. Therefore, the connector section temperature indicated by the line c in FIG. The temperature is lower than in (). Therefore, when the power supply is turned off, heat is transferred by heat conduction from the resistance heating portion 19 on the high temperature side to the connector portion 18 on the low temperature side, so that an excessive temperature rise of the resistance heating portion 19 is suppressed. The temperature difference between the temperature of the resistance heating portion (line b) and the temperature of the connector portion (line c) is reduced.
[0043]
Thereafter, when the resistance heating portion temperature (line b) becomes lower to some extent as compared with the furnace temperature (line a), the energization is switched on again and the resistance heating portion 19 is energized to generate heat, thereby increasing the temperature. The temperature of the entire heat treatment jig 17 may be raised by following the furnace temperature (line a) by appropriately switching the energization ON and the energization OFF. When the furnace temperature (line a) becomes high to some extent, the effect of radiant heat transfer from each of the heaters 11a, 11b, 11c increases, so that the power supply to the heat treatment jig 17 may be kept off. Absent.
[0044]
As described above, according to the above-described method, when the heat treatment target 12 is heated in the heating chamber 2 of the heat treatment furnace, the heat treatment jig 17 itself that holds the heat treatment target 12 is caused to generate resistance heat and the inside of the furnace is heated. Heating can be performed so as to be substantially equal to the temperature, and hybrid heating using both heating by the heater output and resistance heating of the heat treatment jig 17 can be performed. With respect to the heater output of the lower heater 11a, the output for heating the heat treatment jig 17 becomes unnecessary, and the heater output of the lower heater 11a is made substantially equal to the heater output of the other heaters 11b and 11c. Therefore, it is possible to suppress a rise in the temperature of the bottom plate of the heating chamber 2 due to the output of the lower heater 11a, thereby suppressing the amount of heat radiation, and increasing the thermal efficiency.
[0045]
In the above description, when the heat treatment target 12 is heated by each of the heaters 11a, 11b, and 11c, the energization of the heat treatment jig 17 in the heat treatment apparatus of the present invention is performed by setting the heat treatment jig temperature to the furnace internal temperature. However, in the configuration in which the ceramic is placed on the hearth 10 and the heat treatment jig 17 is placed thereon, the heat treatment The furnace floor 10 may be heated by the radiation from the heat-treating jig 17 that has generated heat so that the temperature of the jig slightly exceeds the temperature in the furnace. By doing so, the amount of heat conventionally consumed for heating the hearth 10 can be reduced from the heater output of the lower heater 11a, and the heater output of the lower heater 11a can be further reduced. Similarly to the heater outputs of the heaters 11b and 11c, the heater output required for heating only the heat treatment target 12 can be obtained.
[0046]
Further, in any of the above cases, when the heat treatment jig 17 is energized to generate heat by applying a current to the heat treatment jig 17, the heat treatment object 12 placed and held on the heat treatment jig 17 is In addition, since heat is transferred by the heat conduction from the heat-treating jig 17 that has generated heat, it is possible to directly heat the heat-treating object 12, and therefore, the heat from the heaters 11 a, 11 b, and 11 c as in the related art is required. The heat efficiency for heating the heat treatment target 12 is increased as compared with the case where the heat treatment target 12 is indirectly heated by the radiation or the convection of the radiation and the atmosphere gas heated by the heaters 11a, 11b, 11c. As a result, the processing time can be reduced.
[0047]
Further, since the heat treatment jig 17 is made of a C / C composite, the same strength as that of the conventional heat treatment jig 13 made of a steel material such as SUS can be easily obtained. Since it is possible to significantly reduce the weight as compared with a steel material, the heat capacity can be reduced, and the amount of heat required for heating the heat treatment jig 17 can be reduced, so that energy can be saved. Furthermore, since the resistance to creep can be increased as compared with the above-mentioned conventional steel products, the life as a heat treatment jig can be extended.
[0048]
In the heat treatment furnace, after heating the heat treatment target 12 to a predetermined temperature, and performing a desired heat treatment on the heat treatment target 12 by cooling while controlling the cooling rate, each cylinder of the heat treatment furnace 25 are contracted to separate the left and right electrode members 22 from the outer surface of the connector portion 18 of the heat treatment jig 17, and then, together with the heat treatment jig 17 as in the related art, after the heat treatment. The heat treatment target 12 may be taken out.
[0049]
Next, FIGS. 4 (a), (b) and (c) show an application example of the heat treatment jig 17 of the present invention shown in FIGS. 1 (a) and 1 (b). As described above, when a current flows from the connector section 18 to the resistance heating section 19, the resistance heating section 19 is configured to generate resistance heating by increasing the resistance. In a state where the object to be heat-treated 12 having a smaller electric resistance value than the resistance heating part 19 is placed, the electrode member 22 provided on the heat-treating furnace side is brought into contact with the connector part 18 of the heat-treating jig 17 to conduct electricity. In this case, a circuit may be formed via the heat treatment target 12 itself, and there is a concern that the amount of electricity supplied to the resistance heating unit 19 may be reduced and heat generation may be hindered. Therefore, when the heat treatment is performed on the heat treatment target 12 having a smaller electric resistance value than the resistance heating portion 19, for example, as shown in FIG. A material having heat resistance and insulation properties, for example, an insulating member 30 formed in a required shape such as a net made of a boron material or the like is placed, and the heat treatment target 12 is placed and held thereon. Thus, the electric conduction from the heat treatment jig 17 to the heat treatment target 12 may be prevented by the insulating member 30. Further, as shown in FIG. 4B, the upper and lower end surfaces of the resistance heating portion 19 and the reinforcing member 20 which are exposed on the surface portion of the heat treatment jig 17 and come into contact with the heat treatment target 12, and furthermore, if necessary. Accordingly, oxidizing ceramics such as alumina are sprayed on required portions except the outer surface of the connector portion 18 which is brought into contact with the electrode material 22 on the heat treatment furnace side, such as upper and lower end surfaces of the connector portion 18, so that thermal spraying having insulation and heat resistance is performed. The film 31 may be formed. In this case as well, it is possible to prevent a current from flowing from the heat treatment jig 17 to the heat treatment target 12 in the same manner as described above.
[0050]
Further, as another method for preventing energization from the heat treatment jig 17 to the heat treatment target 12 having a smaller electric resistance value than the resistance heating portion 19, as shown in FIG. Instead of the insulating member 30 having an insulating property as shown in (a), a high-resistance member formed of a material having heat resistance and having a larger resistance value than the resistance heating portion 19 and formed in a required shape such as a mesh. The heat treatment jig 17 may be interposed between the heat treatment jig 17 and the heat treatment object 12 to be placed and held on the heat treatment jig 17. Therefore, even if a current flows from the resistance heating portion 19 to the heat treatment target 12 itself through the high resistance member 32, the amount of current flow can be suppressed to a small value. Ensure that the power is supplied to the 19 can be a resistance-heating.
[0051]
Next, FIG. 5 shows another embodiment of the heat treatment jig in the heat treatment apparatus of the present invention, and has the same configuration as the heat treatment jig 17 shown in FIGS. The outer surface of the connector portion 18, that is, the contact surface with the electrode material 22 provided on the heat treatment furnace side is roughened.
[0052]
Other configurations are the same as those shown in FIGS. 1A and 1B, and the same components are denoted by the same reference numerals.
[0053]
According to the present embodiment, similarly to the heat treatment jig 17 shown in FIGS. 1 (a) and 1 (b), the heat treatment target 12 is placed on the heat treatment jig 17 and held. After the heat treatment target 12 is placed on the hearth 10 of the heat treatment furnace together with the heat treatment jig 17, the electrode materials 22 provided on the heat treatment furnace side are driven to extend the corresponding cylinders 25. When the outer surface of the connector 18 is roughened, the outer surface of the connector 18 and the electrode material 22 are separated. Instead of surface contact, it comes into contact at many points. For this reason, when electric power is supplied from each of the electrode members 22 to the connector portion 18 of the heat treatment jig 17, the electric resistance value is larger than the physical property value at the contact portion between the outer surface of the connector portion 18 and the electrode member 22. Therefore, since the resistance heat is generated, the connector portion 18 can be heated. Therefore, the heat treatment jig 17 in the heat treatment apparatus of the present invention can be used not only in the resistance heat portion 19 but also in the heat treatment device 17. Heat can be generated over the entirety including the connector portion 18.
[0054]
In the above description, the outer surface of the connector portion 18 of the heat treatment jig 17 is shown as being roughened. However, as shown in FIG. While the side surface is kept flat, the distal end surface of the electrode material 22 provided on the heat treatment furnace side may be roughened, or as shown in FIG. May be roughened on both the outer surface of the electrode material and the front end surface of the electrode material 22 on the heat treatment furnace side. In this case, it is apparent that the same effect as described above can be obtained.
[0055]
FIG. 7 shows a further embodiment of the heat treatment apparatus according to the present invention, in which the heat treatment jig is of a basket type. In other words, the basket type heat treatment jig 33 has two C / C composite connector portions 18 having the same configuration as the tray type heat treatment jig 17 shown in FIGS. A bottom plate member 34 having a resistance heating portion 19 for integrally connecting the connector portions 18 and having a jig shape for heat treatment is formed. Further, two C / C composite connector portions 36 each having a square ring shape corresponding to the shape of the bottom plate member 34, each side portion having a required cross-sectional area, and being vertically arranged in parallel at a required interval. , 37, and a vertically extending plate-shaped resistance heating section 38 made of a C / C composite, which is disposed at a required interval in the circumferential direction between the upper and lower connector sections 36, 37. By attaching the upper end and the lower end of each of the resistance heating portions 38 to the lower surface of the upper connector portion 36 and the upper surface of the lower connector portion 37, respectively, the peripheral wall member 35 having a rectangular tube shape as a whole is formed. There is a configuration. With this configuration, by supplying power from an external power supply to the upper and lower connector sections 36 and 37, a circuit that can conduct electricity between the upper and lower connector sections 36 and 37 through the respective resistance heating sections 38 can be formed. When current flows through the connectors 36 and 37 when the circuit is energized, the cross-sectional area where the current flows when the current passes through the respective resistance heating portions 38 is reduced to increase the resistance. The heat generating portion 38 can generate heat.
[0056]
Further, the peripheral wall member 35 is integrally attached to the upper side of the bottom plate member 34 to form a basket type heat treatment jig 33. At this time, the bottom plate member 34 and the peripheral wall member 35 are interposed with a heat-resistant insulating member (not shown) so that the circuit of the bottom plate member 34 and the circuit of the peripheral wall member 35 can be independent circuits. Oxidation that provides heat resistance such as a sprayed coating of alumina on one or both of the upper surface of the outer peripheral edge of the bottom plate member corresponding to the peripheral wall member and the lower end surface of the peripheral wall member and has insulation properties. After forming the thermal spray coating (not shown) of the conductive ceramic, the bottom plate member 34 and the peripheral wall member 35 may be integrated.
[0057]
When the heat treatment object 12 to be stored and held in the heat treatment jig 33 has a small electric resistance value, the connector portion 18 of the bottom plate member 34, the resistance heating portion 19, the reinforcing member 20, the peripheral wall member, and the like. As shown in FIGS. 4A, 4B, and 4C, the insulating member 30 and the high-resistance member 32 are disposed on the inner surface of the resistance heating portion 38 and the connector portions 36 and 37, respectively. What is necessary is just to form the thermal spray coating 31 with the property.
[0058]
The heat treatment furnace for use in the heat treatment of the heat treatment object 12 housed and held in the heat treatment jig 33 in the heat treatment apparatus of the present invention is the same as the heat treatment furnace shown in FIG. The electrode member 22 which can be brought into contact with and separated from the heat treatment jig placed on the hearth 10 by the expansion and contraction operation of the hearth 10 and which is connected to the external power supply unit as shown by a two-dot chain line in FIG. The right and left sides of the hearth 10 at the height positions corresponding to the respective connector portions 18 of the bottom plate member 34 of the heat treatment jig 33, and the height of the hearth 10 at the height corresponding to the upper connector portion 36 of the peripheral wall member 35. The electrode members 22 are disposed at one side position and at the other side position of the hearth 10 at a height corresponding to the lower connector portion 37, respectively, so that the electrode members 22 are connected to the corresponding connector portions 18, 36, 37. Contact with By, it is to be able to flow a current through the respective resistance heating portion 19,38 to the bottom plate member 34 and the peripheral wall member 35.
[0059]
According to the heat treatment jig 33 in the heat treatment apparatus of the present invention shown in FIG. 7, after the heat treatment object 12 is placed on the hearth 10 in a state where the object 12 is housed and held, two points are shown in FIG. As shown by the dashed line, the electrode members 22 provided on the heat treatment furnace side are brought into contact with the respective connector portions 18 of the bottom plate member 34 and the respective connector portions 36 and 37 of the peripheral wall member 35. When power is supplied to the bottom plate member 34 and the peripheral wall member 35, respectively, the resistance heating portion 19 of the bottom plate member 34 generates heat and the resistance heating portion 38 of the peripheral wall member 35 generates heat. Accordingly, the respective heating rates of the bottom plate member 34 and the peripheral wall member 35, which increase in temperature as the corresponding resistance heating portions 19, 38 generate heat, are set to the heat treatment targets by the heaters 11a, 11b, 11c of the heat treatment furnace. If the energization to the bottom plate member 34 and the peripheral wall member 35 is individually controlled to be ON-OFF so as to be able to cope with the rate of increase in the furnace temperature during the heating of 12, the basket-shaped heat treatment jig 33 Even in the case of heating the held heat treatment target 12, heating by the heater output and hybrid heating by resistance heating of the heat treatment jig 33 itself can be performed. Conventionally required for heating the heat treatment jig 33 itself from the heater outputs of the lower heater 11a and the side heater 11c facing the side surface. Need not be included, the heater output of the lower and side heaters 11a and 11c can be reduced as compared with the prior art, and the heat treatment for the heat treatment in the heat treatment apparatus of the present invention shown in FIGS. The same effect as in the case of using the tool 17 can be obtained.
[0060]
FIGS. 8A, 8B and 8C show still another embodiment of the heat treatment jig in the heat treatment apparatus according to the present invention. Are suitable for the case where a predetermined (predetermined) heat treatment target 12a, which is known in advance, is heat-treated constantly. That is, at least two connector members 39 having heat resistance and formed so as to have lower electric resistance than the target heat treatment target 12a, and the heat treatment target 12a sandwiched between the respective connector members 39. It is provided with a bolt and a nut mechanism as a connection mechanism for detachably connecting the respective connector members 39 without directly conducting each other. The heat treatment object 12a is sandwiched between the respective connector members 39. When the object to be heat treated 12a is placed on the hearth 10 of the heat treatment furnace and heated by the heaters 11a, 11b, 11c of the heat treatment furnace in this state, the connector members 39 are placed on the heat treatment furnace side. By connecting the provided electrode material 22 and applying an electric current from each of the connector members 39 via the heat treatment target 12a sandwiched therebetween, It is obtained to be able to resistance heating of the serial thermal processing object 12a itself.
[0061]
More specifically, each of the connector members 39 is, for example, a rectangular flat plate made of a C / C composite and at a plurality of locations (six locations in the figure) slightly shifted to one side in the left-right direction from the point symmetric position. By providing the bolt holes 40 and superposing the connector members 39 which are turned left and right so that the positions of the bolt holes 40 coincide with each other, the positions of the connector members 39 can be shifted from each other in the left-right direction. It is.
[0062]
Therefore, for example, as shown in FIGS. 8 (a) and 8 (b), a large number of cubic heat treatment objects 12a are arranged between the connector members 39 whose right and left are inverted, and these are arranged in a plurality of stages (FIG. 8 (b)). In FIG. 8 (c), a bolt 41 made of a C / C composite is inserted into a bolt hole 40 of each connector member 39, and at the end of the bolt 41, as shown in FIG. By screwing a nut 42 made of C / C composite, an object to be heat-treated can be sandwiched between the connector members 39 shifted in the left-right direction. In order to prevent electricity from flowing between the connector members 39 via the nut 41 and the nut 42, an alumina tube 43 is inserted into the inside of each bolt hole 40 of each of the connector members 39, and the inside thereof is placed on the inside. Together so as to insert the bolt 41, the distal end portion of the bolt 41 are so as to screwed nut 42 through an alumina washer 44.
[0063]
The heat treatment furnace for heat-treating the heat treatment target 12a held by the heat treatment jig of the present embodiment is a heat treatment furnace having the same configuration as that shown in FIG. The electrode material 22 that can be brought into contact with and separated from the heat treatment jig 17 is placed at a height position corresponding to the tray-like heat treatment jig 17 placed on the hearth 10. Instead of having a shape extending along the vertical direction, as shown in FIGS. 8 (a) and 8 (b), the heat treatment target 12a is sandwiched therebetween as described above by providing a configuration having an electrode material 22 extending vertically. As a result, each of the paired connector members 39 is displaced from each other in the left-right direction, so that the electrode material Contact 22, separation And configured to include in order to be able.
[0064]
Therefore, when the heat treatment target 12a is subjected to heat treatment, the heat treatment target 12a is placed on the hearth 10 of the heat treatment furnace with the heat treatment target 12a held between the connector members 39 of the heat treatment jig. (B) As shown by the two-dot chain line in (b), the electrode members 22 provided in the heat treatment furnace are brought into contact with the respective connector members 39 from the corresponding sides in the left-right direction, and in this state, the heaters 11a, 11b When the heat treatment object 12a is heated by the heat treatment object 11a, the connector members 39 are supplied with power from an external power supply device via the heat treatment furnace-side electrode material 22 to form a pair of connector members 39. During the period 39, electric current is supplied through the heat treatment target 12a, thereby causing each heat treatment target 12a itself having a higher electric resistance value than each connector member 39 to generate resistance heat. So as to raise the temperature.
[0065]
As described above, according to the present embodiment, since the temperature of the heat treatment target 12a itself can be directly increased, regardless of the positional relationship between the heaters 11a, 11b, and 11c of the heat treatment furnace and the heat treatment jig. Since the object 12a can be heated almost uniformly, the heater outputs of the heaters 11a, 11 and 11c of the heat treatment furnace can be made almost uniform and can be reduced at the same time, so that the same effect as in the above embodiment can be obtained. Can be.
[0066]
The present invention is not limited to the above embodiment. The heat treatment jig 17 shown in FIGS. 1 (a) and 1 (b) includes at least a pair of connector portions 18 provided at required positions in the tray shape. If the tray shape can be formed firmly from the resistance heating portion 19 connected between the respective connector portions 18, the arrangement of the circuit composed of the connector portion 18 and the resistance heating portion 19 may be freely set. The jig 33 for heat treatment shown in FIG. 7 includes a bottom plate member 34 and a side wall member 35 each having a pair of connector portions 18, 36, 37 and a resistance heating portion 19 connected between the connector portions 18, 36, 37. , 38 are shown as members provided with separate circuits, but the arrangement of the circuits is such that the bottom and side walls are formed by one circuit, or each side wall is formed as a separate circuit. Set freely In the heat treatment jig shown in FIGS. 8A, 8B, and 8C, the heat treatment is performed by holding the cubic heat treatment object 12a between the rectangular flat plate-shaped connector members 39. Although the target heat treatment target 12a is sandwiched between the two connector members 39, the electrode members 22 provided on the heat treatment furnace side are brought into contact with the respective connector members 39. Accordingly, if a circuit can be formed from each of the connector members 39 through which heat can be supplied through the heat treatment target 12a, the shape of the connector member 39 can be freely set according to the target shape of the heat treatment target 12a. As the heat treatment furnace, the arrangement of the connectors 18, 36, and 37 in the heat treatment jig 17 shown in FIGS. 1A and 1B and the heat treatment jig 33 shown in FIG. (I)( If the arrangement of the connector member 39 in the jig for heat treatment shown in (c) can be adapted, the arrangement of the electrode members 22 may be freely set. In addition to the one-chamber type heat treatment furnace, It can be applied to a multi-chamber heat treatment furnace that performs continuous treatment, and may be applied to a heat treatment furnace that performs heat treatment under atmospheric conditions. However, if the material has heat resistance and the required electric resistance, graphite, nichrome, tungsten, molybdenum, tantalum, ceramics (for example, SiC), Fe—Cr -The resistance heating portions 19 and 38 may be formed of one or more materials selected from Al-based materials. In this case, heat resistance and good resistance heat generation can be expected, To the jig The ON / OFF switching of the energization may be performed while the operator visually determines the heating state of the heat treatment jig in the heating chamber 2 from the viewing window 14 and does not deviate from the gist of the present invention. Of course, various changes can be made within the range.
[0067]
【The invention's effect】
As described above, according to the present invention, the following excellent effects are exhibited.
(1) A heat treatment method in which a heat treatment object held by a heat treatment jig in a heat treatment furnace is heated by a heater. In the heat treatment method, the heat treatment jig is further heated by energizing the heat treatment jig to heat the heat treatment object. Therefore, when the object to be heat-treated is heated by the heater output of the heat treatment furnace, hybrid heating can be performed in which the heat treatment jig itself is heated by resistance heat generation and used in combination with the heater outlet. The output can eliminate the need to heat the heat treatment jig, and reduce the heater output of the heater located on the side facing the heat treatment jig to make it approximately equal to the heater output of the other heaters it can. Therefore, the heat loss due to the presence of the heaters having different heater outputs can be reduced, and the thermal efficiency can be improved.
(2) The temperature of the heat treatment object held by the heat treatment jig can be directly increased by heat transfer by increasing the temperature of the heat treatment jig, and the radiation from the heater or the radiation and the heater as in the related art can be achieved. Compared to the case where the object to be heat-treated is heated indirectly by the convection of the atmosphere gas heated by the heat treatment, the thermal efficiency for heating the object to be heat-treated can be increased and the processing time can be shortened become.
(3) Therefore, at least a pair of connector portions and a resistance heating portion having a higher electric resistance value than each connector portion connected between the connector portions so as to hold the object to be heat-treated in the heat treatment furnace. A heat treatment jig is provided, and an electrode material provided on the heat treatment furnace side is brought into contact with each of the connector portions so that current can be supplied between the respective connector portions through the resistance heating portion. In the heating chamber surrounded by the heat treatment apparatus and the heat insulating wall, the heat treatment target placed together with the heat treatment jig on the hearth provided at the bottom of the heating chamber, the ceiling of the heating chamber, the inner bottom and In the heating chamber of the heat treatment furnace which can be heated by the output of the heater disposed on each of the side wall portions, it is possible to come into contact with and separate from each connector portion provided on the heat treatment jig placed on the hearth in the heating chamber. electrode A heat treatment furnace comprising a material, when heating the object to be heat treated by the output of each heater, the electrode material is brought into contact with the connector portion of the heat treatment jig so that the heat treatment jig can be energized. By using the above method, the above method can be performed, and therefore, the heater output of the heater can be made uniform. Therefore, it is possible to suppress a partial temperature rise in the heating chamber and to suppress the amount of heat radiation. As a result, the thermal efficiency can be increased.
(4) In addition to the above (3), the object to be heat-treated can be directly heated by a heat-treating jig that raises the temperature, so that radiation from the heater or radiation from the heater and the heater as in the related art are used. As compared with the case where the heat treatment target is indirectly heated only by the convection of the atmosphere gas heated by the heat treatment, the heat efficiency when heating the heat treatment target can be increased, and the processing time can be shortened. Will be possible.
(5) The heat treatment jig is disposed in a region between the pair of connector portions spaced apart along one opposing side of the required tray shape and the connector portions serving as the tray-shaped surface portions. In this configuration, a tray-shaped heat treatment jig can be easily formed by integrally connecting resistance heating portions arranged in parallel at required intervals in the longitudinal direction.
(6) In addition, since the outer surface of the connector portion of the heat treatment jig is roughened, the connector portion of the tray-shaped heat treatment jig can also generate resistance heat.
(7) A jig for heat treatment is provided on at least one pair of connector portions exposed on opposing side surfaces of the basket-shaped outer peripheral portion, and the basket-shaped side wall portion position and the bottom plate portion are provided between the connector portions. A circuit capable of connecting the resistance heating parts arranged at the same position, and energizing through the resistance heating parts arranged at the side wall part position and the bottom plate part position of the basket between the corresponding connector parts. Can be formed so that a basket-shaped heat treatment jig can be easily formed.
(8) Further, a configuration in which a thermal spray coating of an oxidizable ceramic is formed on a contact surface of the resistance heating portion of the heat treatment jig with the heat treatment target, or a heat treatment target of the resistance heat generation portion of the heat treatment jig By providing an insulating member having an insulating property or a high resistance member having an electric resistance value larger than that of the resistance heating section on the contact surface portion with the object, the electric resistance is higher than that of the resistance heating section. The heat treatment method of the present invention can be performed in a state where the heat treatment jig is held by each of the heat treatment jigs, even if the heat treatment target is small.
(9) In the above, among the materials of the resistance heating portion of the heat treatment jig, graphite materials, nichrome materials, tungsten materials, molybdenum materials, tantalum materials, ceramic materials (for example, SiC), and Fe-Cr-Al-based materials By using one or a plurality of materials selected from the above, it is possible to easily form a resistance heating portion having heat resistance and good resistance to heat generation.
(10) Further, in the heat treatment method of heating a heat treatment object held by a heat treatment jig in a heat treatment furnace with a heater, the heat treatment object is treated with a heat treatment jig having a smaller electric resistance value than the heat treatment object. A heat treatment method characterized by heating the heat treatment object by energizing the heat treatment object through the heat treatment object between the heat treatment jigs and holding the heat treatment object. At least one pair of connector members having an electric resistance value smaller than that of the object, and an insulated connection mechanism for detachably connecting the pair of connector members to each other while holding the object to be heat-treated therebetween. A jig for heat treatment, and when heat-treating the object to be heat-treated in the heat treatment furnace, the electrode material provided on the heat treatment furnace side is brought into contact with each of the connector members forming the pair, and between the respective connector members. Above heat By using a heat treatment apparatus that can be energized through the treatment object, when heating the heat treatment object by the heater output of the heat treatment furnace, the heat treatment object is energized and the heat treatment object itself is heated. Since the temperature can be directly increased, the object to be heat-treated can be heated almost uniformly regardless of the positional relationship between each heater and the heat treatment jig, and the heater output of the heat treatment furnace can be made substantially uniform. As a result, the same effects as above can be obtained.
(11) Since the heat treatment jig is made of a C / C composite material, the heat capacity of the heat treatment jig itself can be reduced. The required energy can be reduced, and the creep resistance can be enhanced.
[Brief description of the drawings]
FIG. 1 shows a heat treatment jig in the form of a tray as an embodiment of the heat treatment apparatus of the present invention, wherein (a) is a schematic front view, and (b) is a schematic plan view. is there.
FIG. 2 shows one embodiment of the heat treatment furnace of the present invention, and shows a schematic cut front view.
3A and 3B show a method of controlling energization to the heat treatment jig shown in FIG. 1 in the heat treatment furnace shown in FIG. 2, and FIG. It is a figure which shows the temperature change of a connector part temperature, and (b) is a figure which shows the timing of the switching operation of ON-OFF of electricity supply to the jig for heat processing.
FIG. 4 is a diagram showing a countermeasure for preventing the heat treatment jig of FIG. 1 from energizing a heat treatment target having a lower electric resistance value than a resistance heating portion of the heat treatment jig. ) Shows a state in which an insulating member is interposed between the heat treatment jig and the object to be heat treated. (B) shows a state in which an insulating sprayed film is formed on the surface of the heat treatment jig. () Is a schematic front view showing a state in which a high resistance member is interposed between the jig for heat treatment and the object to be heat treated.
FIG. 5 shows another embodiment of the heat treatment apparatus of the present invention, and is an enlarged view of a connector section.
6A and 6B show a means for generating heat in a connector portion of a heat treatment jig. FIG. 6A shows a state in which a front end surface of an electrode material on a heat treatment furnace side is roughened, and FIG. It is a principal part enlarged view which shows the state which roughened both the outer surface of the connector part of the tool, and the front-end | tip surface of the electrode material of a heat treatment furnace side, respectively.
FIG. 7 is a schematic perspective view showing a heat treatment jig in a basket shape as still another embodiment of the heat treatment apparatus of the present invention.
8A and 8B show still another embodiment of the heat treatment apparatus of the present invention, wherein FIG. 8A is a schematic plan view, FIG. 8B is a schematic front view, and FIG. FIG.
FIG. 9 schematically shows an example of a heat treatment furnace generally used in the related art, in which (a) is a cut side view, and (b) is a cut front view.
[Explanation of symbols]
2 heating room
10 Hearth
11a, 11b, 11c heater
12 Heat treatment target
17 Jig for heat treatment
18 Connector section
19 Resistance heating section
22 Electrode materials
30 Insulation member
31 Thermal spray coating
32 High resistance material
33 Jig for heat treatment
34 Bottom plate member (bottom plate part)
35 Perimeter wall member (side wall)
36 Upper connector part (connector part)
37 Lower connector part (connector part)
38 Resistance heating section
39 Connector member
41 bolt (connection mechanism)
42 nut (connection mechanism)

Claims

In a heat treatment method of heating a heat treatment object held by a heat treatment jig in a heat treatment furnace with a heater, the method further comprises energizing and heating the heat treatment jig to heat the heat treatment object. Heat treatment method.

In a heat treatment method of heating a heat treatment object held by a heat treatment jig in a heat treatment furnace with a heater, the heat treatment object is sandwiched between heat treatment jigs having a smaller electric resistance value than the heat treatment object. A heat treatment method, characterized in that the heat treatment object is heated while being held and energized through the heat treatment object between the heat treatment jigs.

A heat treatment jig including at least a pair of connector portions and a resistance heating portion having a higher electric resistance value than each connector portion connected between the connector portions so as to hold the heat treatment target in the heat treatment furnace. And a structure in which an electrode material provided on the heat treatment furnace side is brought into contact with each of the connector portions so that current can flow between the respective connector portions through the resistance heating portion. Equipment for heat treatment.

A heat treatment jig is disposed in a region between the pair of connector portions spaced apart along one opposing side of the required tray shape and the respective connector portions serving as the tray-shaped surface portions in the longitudinal direction of the respective connector portions. 4. The apparatus for heat treatment according to claim 3, wherein the resistance heating parts arranged in parallel at required intervals are integrally connected.

The heat treatment apparatus according to claim 4, wherein the outer surface of the connector portion of the heat treatment jig is roughened.

Heat treatment jigs are provided on at least a pair of exposed connector portions on opposing side surfaces of the basket-shaped outer peripheral portion, and are disposed between the connector portions at the side wall portion position and the bottom plate portion position of the basket shape. By connecting integrally the resistance heating portions formed as described above, it is possible to form a circuit that can be energized between the corresponding connector portions via the resistance heating portions disposed at the side wall portion position and the bottom plate portion position of the basket shape. An apparatus for heat treatment according to claim 3, wherein

7. The heat treatment apparatus according to claim 3, wherein a thermal spray coating of an oxidizable ceramic is formed on a contact surface portion of the resistance heating section of the heat treatment jig with the heat treatment target.

An insulating member having an insulating property or a high-resistance member having an electric resistance value larger than that of the resistance heating portion is disposed on a contact surface portion of the resistance heating portion of the jig for heat treatment with the object to be heat-treated. 7. The apparatus for heat treatment according to 3, 4, 5 or 6.

At least one pair of connector members having an electric resistance value smaller than that of the target object to be heat-treated and insulated for detachably connecting the pair of connector members to each other while holding the object to be heat-treated. A jig for heat treatment comprising a coupling mechanism, and when heat-treating the object to be heat-treated in a heat treatment furnace, an electrode material provided on the heat treatment furnace side is brought into contact with each of the pair of connector members, and An apparatus for heat treatment, characterized in that it is configured to be able to conduct electricity between the connector members via the object to be heat-treated.

The material for the resistance heating portion of the heat treatment jig is one or more materials selected from a graphite material, a nichrome material, a tungsten material, a molybdenum material, and a tantalum material. , 6, 7 or 8.

The heat treatment apparatus according to claim 3, 4, 5, 6, 7, 8, or 9, wherein a material of the heat treatment jig is made of C / C composite.

In a heating chamber surrounded by heat insulating walls, heat treatment objects placed together with heat treatment jigs on a hearth provided at the bottom of the heating chamber are arranged on the ceiling, inner bottom, and side walls of the heating chamber. In the heat treatment chamber of the heat treatment furnace that can be heated by the output of the provided heater, an electrode material capable of coming into contact with and detaching from each of the connector portions provided on the heat treatment jig placed on the hearth is provided. A heat treatment furnace characterized in that when heating an object to be heat-treated by an output of each of the heaters, the electrode material is brought into contact with a connector portion of the heat treatment jig so that the heat treatment jig can be energized. .