[go: up one dir, main page]
More Web Proxy on the site http://driver.im/

BR112018069722A2 - material de aço de alta resistência e seu método de produção - Google Patents

material de aço de alta resistência e seu método de produção

Info

Publication number
BR112018069722A2
BR112018069722A2 BR112018069722A BR112018069722A BR112018069722A2 BR 112018069722 A2 BR112018069722 A2 BR 112018069722A2 BR 112018069722 A BR112018069722 A BR 112018069722A BR 112018069722 A BR112018069722 A BR 112018069722A BR 112018069722 A2 BR112018069722 A2 BR 112018069722A2
Authority
BR
Brazil
Prior art keywords
less
high strength
steel material
strength steel
production method
Prior art date
Application number
BR112018069722A
Other languages
English (en)
Other versions
BR112018069722B1 (pt
Inventor
Yoshida Shinji
Arari Yuji
Original Assignee
Nippon Steel & Sumitomo Metal Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nippon Steel & Sumitomo Metal Corp filed Critical Nippon Steel & Sumitomo Metal Corp
Publication of BR112018069722A2 publication Critical patent/BR112018069722A2/pt
Publication of BR112018069722B1 publication Critical patent/BR112018069722B1/pt

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/005—Modifying the physical properties by deformation combined with, or followed by, heat treatment of ferrous alloys
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/001—Heat treatment of ferrous alloys containing Ni
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/002—Heat treatment of ferrous alloys containing Cr
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/005—Heat treatment of ferrous alloys containing Mn
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/008—Heat treatment of ferrous alloys containing Si
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/10—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of tubular bodies
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/10—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of tubular bodies
    • C21D8/105—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of tubular bodies of ferrous alloys
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/001—Ferrous alloys, e.g. steel alloys containing N
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/08—Ferrous alloys, e.g. steel alloys containing nickel
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/16—Ferrous alloys, e.g. steel alloys containing copper
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/24—Ferrous alloys, e.g. steel alloys containing chromium with vanadium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/38—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of manganese
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/58—Ferrous alloys, e.g. steel alloys containing chromium with nickel with more than 1.5% by weight of manganese
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/004—Dispersions; Precipitations

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Heat Treatment Of Steel (AREA)

Abstract

um material de aço de alta resistência que possui uma composição química contendo, em % em massa, c: 0,30 a 1,0%, si: 0,05 a 1,0%, mn: 16,0 a 35,0%, p: 0,030% ou menos, s: 0,030% ou menos, al: 0,003 a 0,06%, n: 0,1% ou menos, v: 0 a 3,0%, ti: 0 a 1,5%, nb: 0 a 1,5%, cr: 0 a 5,0%, mo: 0 a 3,0% cu: 0 a 1,0%, ni: 0 a 1,0%, b: 0 a 0,02%, zr: 0 a 0,5%, ta: 0 a 0,5%, ca: 0 a 0,005%, mg: 0 a 0,005%, e o equilíbrio: fe e impurezas, e que satisfaz [v+ti+nb> 2,0], em que: uma densidade numérica de carbetos/carbonitretos tendo um diâmetro equivalente a um círculo de 5 a 30 nm precipitando no aço é 50 para 700 /micrômetro ao quadrado, e uma densidade numérica de carbetos/carbonitretos com um diâmetro equivalente ao círculo de mais de 100 nm que precipita no aço é inferior a 10 /micrômetro ao quadrado; um limite elástico é de 758 mpa ou mais; e um valor de k(issc) obtido em um teste dcb é de 33,7 mpa x (m elevado a 0,5) ou mais.
BR112018069722-2A 2016-03-30 2017-03-15 Material de aço de alta resistência e seu método de produção BR112018069722B1 (pt)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2016067741 2016-03-30
JP2016-067741 2016-03-30
PCT/JP2017/010531 WO2017169811A1 (ja) 2016-03-30 2017-03-15 高強度鋼材およびその製造方法

Publications (2)

Publication Number Publication Date
BR112018069722A2 true BR112018069722A2 (pt) 2019-02-05
BR112018069722B1 BR112018069722B1 (pt) 2022-08-23

Family

ID=59965249

Family Applications (1)

Application Number Title Priority Date Filing Date
BR112018069722-2A BR112018069722B1 (pt) 2016-03-30 2017-03-15 Material de aço de alta resistência e seu método de produção

Country Status (9)

Country Link
US (1) US10988819B2 (pt)
EP (1) EP3438312B1 (pt)
JP (1) JP6597887B2 (pt)
CN (1) CN108884539A (pt)
BR (1) BR112018069722B1 (pt)
CA (1) CA3019483A1 (pt)
MX (1) MX2018011714A (pt)
RU (1) RU2687328C1 (pt)
WO (1) WO2017169811A1 (pt)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA3089461A1 (en) * 2018-04-09 2019-10-17 Nippon Steel Corporation Steel pipe and method for producing steel pipe
AU2019340624B2 (en) * 2018-09-12 2021-11-11 Jfe Steel Corporation Steel material and method of producing same
KR102218441B1 (ko) * 2019-10-08 2021-02-19 주식회사 포스코 비자성 고강도 선재 및 이의 제조방법
EP4101938A4 (en) * 2020-02-03 2024-06-05 Nippon Steel Corporation STEEL MATERIAL FOR OIL WELLS, AND OIL WELL PIPE
JP7380655B2 (ja) * 2020-08-07 2023-11-15 Ｊｆｅスチール株式会社 鋼材およびその製造方法
CN112281057A (zh) * 2020-10-14 2021-01-29 东北大学 一种具有不同晶粒尺寸和孪晶含量的twip钢板及其制备方法
CN114763593B (zh) * 2021-01-12 2023-03-14 宝山钢铁股份有限公司 具有耐高湿热大气腐蚀性的海洋工程用钢及其制造方法

Family Cites Families (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5118916A (ja) 1974-08-09 1976-02-14 Nippon Steel Corp Teionjinseinosugureta oosutenaitokono seizoho
JPS5236513A (en) 1975-09-18 1977-03-19 Daido Steel Co Ltd Strong and tough steel used at extremely low temperature
JPS6039150A (ja) 1983-08-12 1985-02-28 Nippon Steel Corp 応力腐食割れ抵抗の優れた油井管用鋼
EP0174418B1 (en) * 1984-05-22 1990-05-23 Westinghouse Electric Corporation Austenitic alloys based on iron-manganese and iron-manganese-chromium
JPH09249940A (ja) * 1996-03-13 1997-09-22 Sumitomo Metal Ind Ltd 耐硫化物応力割れ性に優れる高強度鋼材およびその製造方法
JP3787224B2 (ja) 1996-08-29 2006-06-21 株式会社大東製作所 摺動軸部材および非磁性軸部材
JP3379355B2 (ja) * 1996-10-21 2003-02-24 住友金属工業株式会社 耐硫化物応力割れ性を必要とする環境で使用される高強度鋼材およびその製造方法
JP2001131713A (ja) 1999-11-05 2001-05-15 Nisshin Steel Co Ltd Ｔｉ含有超高強度準安定オーステナイト系ステンレス鋼材および製造法
JP2008519160A (ja) 2004-11-03 2008-06-05 ティッセンクルップ スチール アクチェンゲゼルシャフト Ｔｗｉｐ特性をもつ高強度の鋼ストリップ又はシートの製造方法、コンポーネント及び高強度鋼ストリップ又はシートの製造方法
CN101307415A (zh) 2008-07-14 2008-11-19 四川大学 一种整体具有良好耐磨性的奥氏体不锈钢
DE102008056844A1 (de) * 2008-11-12 2010-06-02 Voestalpine Stahl Gmbh Manganstahlband und Verfahren zur Herstellung desselben
CN101597721A (zh) * 2009-07-08 2009-12-09 中原特钢股份有限公司 无磁钻具用钢及其生产方法
US20120160363A1 (en) * 2010-12-28 2012-06-28 Exxonmobil Research And Engineering Company High manganese containing steels for oil, gas and petrochemical applications
JP5880836B2 (ja) 2011-03-21 2016-03-09 大同特殊鋼株式会社 析出強化型耐熱鋼及びその加工方法
KR101591611B1 (ko) 2011-07-06 2016-02-03 신닛테츠스미킨 카부시키카이샤 냉연 강판의 제조 방법
MX357255B (es) 2011-07-27 2018-07-03 Nippon Steel & Sumitomo Metal Corp Lamina de acero laminada en frio de alta resistencia que tiene excelente capacidad de conformacion en formas complejas y capacidad de perforacion de precision y metodo de fabricacion de la misma.
AU2014294080B2 (en) * 2013-07-26 2017-05-25 Nippon Steel Corporation High-strength steel material for oil well and oil well pipes
MX2017004258A (es) * 2014-10-01 2017-06-06 Nippon Steel & Sumitomo Metal Corp Material de acero de alta resistencia para pozos de petróleo y productos tubulares para la industria del petróleo.
JP6451545B2 (ja) 2015-08-05 2019-01-16 新日鐵住金株式会社 高圧水素ガス用高Ｍｎ鋼鋼材およびその製造方法、ならびにその鋼材からなる、配管、容器、バルブおよび継手

Also Published As

Publication number Publication date
EP3438312B1 (en) 2020-12-23
CA3019483A1 (en) 2017-10-05
EP3438312A1 (en) 2019-02-06
RU2687328C1 (ru) 2019-05-13
MX2018011714A (es) 2019-02-18
BR112018069722B1 (pt) 2022-08-23
JP6597887B2 (ja) 2019-10-30
US20200123624A1 (en) 2020-04-23
WO2017169811A1 (ja) 2017-10-05
EP3438312A4 (en) 2019-04-24
CN108884539A (zh) 2018-11-23
JPWO2017169811A1 (ja) 2018-11-29
US10988819B2 (en) 2021-04-27

Similar Documents

Publication Publication Date Title
BR112018069722A2 (pt) material de aço de alta resistência e seu método de produção
BR112017000121A2 (pt) aço inoxidável austenítico e método de fabricação para o mesmo
MX2019004721A (es) Tubo sin costura de acero inoxidable martensitico para productos tubulares de region petrolifera, y metodo para la produccion del mismo.
BR112017001430A2 (pt) ?cano de aço de baixa liga para poço de óleo?
BR112017005540A2 (pt) ?material de aço de alta resistibilidade para poço de óleo e mercadorias tubulares de indústria petrolífera?
MX2019010538A (es) Aleacion resistente a la corrosion con alto contenido de nitrogeno, elementos principales multiples, con alta entropia.
BR112018068914A2 (pt) cano de aço inoxidável sem costura de alta resistibilidade para poço de óleo
BR112017019994A2 (pt) membro de folha de aço tratada termicamente e método para produzir o mesmo
BR112018069311A8 (pt) Material de aço inoxidável austenítico
BR112018000188A2 (pt) aço inoxidável austenítico e método para produção de aço inoxidável austenítico
BR112018072904A2 (pt) barra de aço para membro de fundo de poço e membro de fundo de poço
BR112022019162A2 (pt) Material de aço
UA117494C2 (uk) Високоміцна марганцева сталь для нафтової свердловини і труба для нафтових свердловин
BR112012011594A2 (pt) aço inoxidável austenítico pobre
BR112016011895A2 (pt) Liga forjável de níquel-cromo-cobalto-titânio-alumínio endurecedora, e seus usos
MX2020002864A (es) Tubo sin costura de acero inoxidable martensitico para productos tubulares de region petrolifera, y metodo para la fabricacion del mismo.
BR112019002999A2 (pt) aço inoxidável de fase dupla e método de produção do mesmo
BR112018073053A2 (pt) tubo de aço sem costura e método para produzir o tubo de aço sem costura
AR100722A1 (es) Tubo de acero de baja aleación para un pozo de petróleo
BR112015013006A2 (pt) liga de aço inoxidável martensítico temperável por precipitação
BR112015032337A2 (pt) material de aço resistente à abrasão excelente em características de fadiga e método de produção do mesmo
BR112018017250A2 (pt) tubo de aço sem costura de alta resistibilidade de baixa liga para produtos tubulares petrolíferos
MX2020002836A (es) Tubo sin costura de acero inoxidable martensitico para productos tubulares de region petrolifera, y metodo para la fabricacion del mismo.
BR112017025795A2 (pt) aço resistente à corrosão, método de produção do dito aço e uso do mesmo
MX2019008642A (es) Material de acero y metodo para la produccion del material de acero.

Legal Events

Date Code Title Description
B25D Requested change of name of applicant approved

Owner name: NIPPON STEEL CORPORATION (JP)

B06W Patent application suspended after preliminary examination (for patents with searches from other patent authorities) chapter 6.23 patent gazette]
B350 Update of information on the portal [chapter 15.35 patent gazette]
B09A Decision: intention to grant [chapter 9.1 patent gazette]
B16A Patent or certificate of addition of invention granted [chapter 16.1 patent gazette]

Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 15/03/2017, OBSERVADAS AS CONDICOES LEGAIS

B09W Correction of the decision to grant [chapter 9.1.4 patent gazette]

Free format text: REFERENTE A RPI 2687 DE 05/07/2022.