CN1505691A

CN1505691A - A cast shaped article made from high strenght, precipiation-hardenable stainless steel and a process for making same

Info

Publication number: CN1505691A
Application number: CNA028092252A
Authority: CN
Inventors: Jw; J·W·马丁
Original assignee: CRS Holdings LLC
Current assignee: CRS Holdings LLC
Priority date: 2001-03-02
Filing date: 2002-02-28
Publication date: 2004-06-16
Also published as: WO2002070768A2; US20020164261A1; TW575666B; JP2004531642A; WO2002070768A3

Abstract

A shaped article which is manufactured by casting in air or under inert-gas shrouding at atmospheric pressure is disclosed. The shpaed articl eprovdies a surerior combination of high strength, hardness, ductility, and corrosion resistance compared to the known air. castable stainless steels. A cast article in accordance with this inveniton is made from a high strenght, astable, stainless steel alloy having the following weight percent composition C 0.1 max., Mn 2 max., Si 1 max., P 0.05 max., S 0.05 max., Cr 9-13, Ni 4-8, Mo 4-8, Co 8-16, N 0.1 max. The balance of the alloy is essentially iron and the usual impurities. A process for making such an article is also described.

Description

But the cast form goods and the manufacture method thereof that produce by high strength precipitation-hardening stainless material

Technical field

But the present invention relates to the molded article that forms by high strength precipitation-hardening stainless material casting and the manufacture method of this goods.More specifically, the present invention relates to the casting golf club head made by this alloy material.

Background technology

Be acquisition advantage in competition, golf club manufacturer grows to even greater heights to the high strength that can cast in air, the demand of corrosion resistant alloy material.So far, based on high strength, high rigidity and the good solidity to corrosion that it had simultaneously, but the precipitation-hardening stainless material is used to these purposes always.For example, but be numbered in the international application of WO 01/79576 in publication a kind of being suitable for be illustrated at high strength, the martensite precipitation-hardening stainless material of the casting of air medium section.In this patent application, high strength is defined as working as alloy material under solution treatment and age hardening condition, and its room temperature yield strength is at least about 190ksi.The common yield strength of this alloy material that illustrates in disclosed international application reaches as high as about 200ksi, ultimate tensile strength reaches as high as about 210ksi.

But although can realize different parameter characteristics such as high strength, toughness and solidity to corrosion combinations by existing precipitation-hardening stainless material, but in those alloy materials, all used the element that has than high reaction activity, for example in the age hardening heat treatment process, generated titanium or the aluminium element of strengthening precipitate with nickel reactant.Yet titanium or aluminium have stronger affinity to oxygen and nitrogen.Because molten metal can some untoward reactions take place with oxygen and nitrogen when being exposed in the air, the alloy material that therefore contains those elements is unsuitable for molded shapes goods in air.Can not provide enough protections with molten metal and air insulated as metallic substance as the method for using inert gas atmosphere.Therefore use this steel directly not obtain in air or non-vacuum condition under the economic benefit that had of melting treatment and casting.

Carpenter Science and Technology Ltd. (Carpenter Technology Corporation) but sold a kind of wrought of stainless steel and iron base alloy material age-hardenable, its commodity are called PYROMET X-23.This kind alloy material has good nmotch tensile strength (that is: NTS/UTS 〉=1) and good stretching ductility, and its ultimate tensile strength reaches as high as about 260ksi.Based on its good comprehensive performances, as high strength, high tenacity, good solidity to corrosion and thermostability, PYROMET X-23 alloy is mainly used in the gun barrel material.Here, thermostability refers to that alloy material does not produce the ability of embrittlement in the 700-1000F temperature range.PYROMET X-23 alloy material is produced as vacuum fusion (being VIM) product or secondary vacuum fusion (being VIM/VAR) product usually.

Summary of the invention

As described herein, be provided at the molded article that Foundry Production goes out in air or inert gas atmosphere under the atmospheric pressure.Compare with the existing stainless material that can cast in air, the over-all properties that goods had is better as described in the present invention, i.e. high strength, high rigidity, good ductility and good solidity to corrosion.Cast product is cast the stainless steel alloy material manufacturing and is formed by high-strength as described in the present invention, and its component has following broad, medium and preferred weight percentage scope.

Relative broad range Medium range Preferable range

C maximum value 0.1 maximum value 0.025 maximum value 0.015

Mn maximum value 2 maximum values 1 maximum value 0.5

Si maximum value 1 maximum value 1 maximum value 0.5

P maximum value 0.05 maximum value 0.04 maximum value 0.03

S maximum value 0.05 maximum value 0.03 maximum value 0.01

Cr??????9-13?????????????9.5-12?????????10.0-11.5

Ni??????4-8??????????????5-8????????????5.5-7.5

Mo??????4-8??????????????4-8????????????5-6

Co??????8-16?????????????8-16???????????9.5-13.5

N maximum value 0.1 maximum value 0.025 maximum value 0.015

The remaining component of alloy material be mainly iron and the stainless material commercial grade age-hardenable in close purposes or service, used in common impurity.In addition, alloy material can contain selectively and is up to about 1% niobium or niobium and/or tantalum.Alloy material also can contain and is up to about 0.02% boron.A kind of cast product of being made by this alloy material as golf club head, has the yield strength that is at least about 220ksi and good toughness and ductility.

Previous list thus not as the lower value and the higher limit that limit each alloy compositions constituent content that is used in combination among the present invention, or does not limit elemental range independent and that other component element is used in combination only as table look-up.Thus, the component element of one or more broad component content ranges can use with other scopes of one or more all the other elements that are positioned at medium or preferred ingredient content range.In addition, the element that is positioned at broad, medium or preferred ingredient content range of minimum or maximum can mix use with the element of one of other different components content range of maximum or minimum.

In this application, except as otherwise noted, term " per-cent " or symbol " % " expression weight percentage.Simultaneously, term " yield strength " expression is to be parallel to the offset yield strength that the stress-strain curve recoverable deformation corresponding stress numerical of collinear intersection point is partly obtained at 0.2% o'clock by stress-strain curve and strain deviation amount.

Another aspect of the present invention provides the production method of a molded article.Comprise in the production method that fusion has this step of stainless steel alloy material of aforementioned any weight alloy percentage composition of listing.The molten alloy material is poured into the curable molded article of formation in the mold.Then in the higher temperature heating enough time of molded article, so that the complete basically homogenizing of the composition of molded article and microtexture.Then molded article is heat-treated, use required intensity and flexible combination so that molded article reaches.

Embodiment

Alloying constituent in weight percentage scope described in the last table all is applicable to casting golf club element in air.Alloy material can realize being at least about 220ksi room temperature ultimate tensile strength economically, also keeps being applicable to the enough ductility of golf club and solidity to corrosion preferably simultaneously.But the wrought of bulk alloy composition comprises forging, band and tubing, also can be used for golf club, and is simultaneously compatible with the element of casting in air.Product among the present invention also can be used for and the incoherent small parts of golf industry, for example gun assembly.

An importance of the present invention is that the bulk alloy composition is to the responding ability of age hardening under the situation of no high reaction activity element such as titanium or aluminium.Precipitation takes place by Ni-Al or Ni-Ti compound and has higher intensity in the stainless material age-hardenable that contains titanium and/or aluminium in the low carbon martensite matrix.On the contrary, should be known as " R " phase, Precipitation Reaction takes place and carry out age hardening with described alloy material by the rich Cr phase of Co/Mo/ intermetallic compound.Because do not have the high reaction activity element in the alloy material, the used alloy material of the present invention forms oxide compound and/or nitride in alloy substrate ability weakens.In addition, when molten metal was exposed in the air, the used alloy material of the present invention reduced the susceptibility that other component concentration changes as decarburizing reaction in remelting and castingprocesses.

The alloy material that is used for cast product as described herein contains at least about 9%, at least about 9.5% preferable, preferably at least about 10.0% chromium, with in oxidisability, comprising obtaining enough solidity to corrosions under the atmospheric exposure condition.Although the increase of chromium content helps to improve the solidity to corrosion of alloy material, the chromium too high levels is unfavorable for the toughness and the phase stability of alloy material.Elemental chromium be owing to can promote ferritic formation and keep excessive austenite, thereby is unfavorable for the phase stability of alloy material.Therefore, it is about 1 3% that chromium content should not surpass, and is no more than about 12% preferablely, preferably is no more than about 11.5%.

Element cobalt serves many purposes in alloy material of the present invention.For example, element cobalt promotes austenitic formation, and then helps the toughness of alloy material.Simultaneously element cobalt has also participated in the age-hardening process that Precipitation Reaction takes place mutually " R ".For reaching better effects, cobalt element content is at least about 8%, preferably at least about 9.5%.The cobalt element too high levels can make the austenite in the alloy material very stable, so that martensite can not produce complete deformation in quenching process, hinders more high strength and hardness that the alloy material acquisition can reach thus.Increase cobalt element content and also increased the alloy manufacturing cost simultaneously, and can not bring further economic benefit.For these reasons, cobalt element content should not surpass approximately 16% in the alloy, preferably is no more than about 13.5%.

The same with cobalt element, the existence of nickel element is same to promote austenitic formation, and then helps the toughness of alloy material.Therefore, cast article alloy material of the present invention is to obtain better toughness and ductility, nickel element content at least about 4%, at least about 5% preferable, preferably at least about 5.5%.Yet the existence of nickel element also has a strong impact on the austeno-martensite transformation that takes place in quenching process.Therefore, nickel element content should not surpass approximately 8% in the alloy, preferably is no more than about 7.5%.

Because the existence of molybdenum not only helps the formation that " R " strengthens precipitate mutually, and helps toughness, ductility and the solidity to corrosion of alloy material, therefore in alloy material of the present invention, contain at least about 4%, preferably at least about 5% molybdenum element.On the other hand, keep too much austenite because the molybdenum too high levels can make in the alloy material, promote to generate disadvantageous ferrite, therefore, molybdenum content should not surpass approximately 8% in the alloy, preferably is no more than about 6%.All or part of molybdenum element can be substituted by the W elements of a great deal of.Known to the professional and technical personnel, substitute the specified rate molybdenum element and suitable effect is provided with W elements according to following ratio: promptly per 1% molybdenum element is equivalent to about 2% W elements.

Because having of element silicon is beneficial to the flowability of alloy material in castingprocesses, therefore in the used alloy material of the present invention, can contain minor amount of silicon, as: about 0.01%-0.02%.Simultaneously also favourable as the element silicon of deoxidation agent.Because element silicon is ferrite former, its concentration should not surpass approximately 1% in alloy material, preferably is no more than about 0.5%.

Be used for the alloy material of cast product as described herein and can contain niobium element selectively up to about 1%.Because the reactive behavior of niobium element and oxygen and nitrogen far is weaker than titanium or aluminium, so the existence of niobium element can not damage the aerial castability of alloy material.In addition, because niobium can form rich nickel-niobium intermetallic compound mutually with nickel, play the effect of the martensitic matrix in the reinforced alloys, so the niobium element helps improving the intensity of alloy material.Because niobium element content surpasses about 1% and will be unfavorable for the toughness and the ductility of alloy in the alloy material, so the amount of the niobium element that uses in the alloy is subject to aforementioned quantities.The available element tantalum is with 2 to 1 all or part of substitute niobium element of ratio based on weight percentage.

Because boron helps the hot workability and the toughness of alloy material, the alloy material that is used for casting object as described herein also can be on a small quantity but is contained boron up to about 0.02% effectively.Boron also can be used as the deoxidation agent.Although the hot workability common principal element of considering that is not cast product can hot work operation remelting and casting goods used according to the invention in the section bar process of producing product.

But all the other compositions of alloy material are mainly iron and the precipitation-hardening stainless material commercial grade in close purposes or service, used in common impurity.In this respect, contain carbon, nitrogen, manganese, p and s inevitably in the used alloy of the present invention.Yet these elements no matter are separately or combination exists, if too high levels all is unfavorable for the intensity and the toughness of alloy material, therefore will control the amount of these elements.In sosoloid, carbon and nitrogen are austenitic strong stability agent.Their excessive concentration are unfavorable for the phase stability of alloy material.Simultaneously, carbon and ammonia are easy to combine with chromium and form unwanted carbide, nitride and carbonitride.Therefore, it is about 0.1% that carbon and nitrogen content are limited not to surpass separately, is no more than about 0.025% preferablely, preferably is no more than about 0.015%.

It is about 1% that manganese content is limited not to surpass, and preferably is no more than about 0.5%.It is about 0.050% that phosphorus content is limited not to surpass, and is no more than about 0.040% preferablely, preferably is no more than about 0.030%.Because the mechanical property and the solidity to corrosion of alloy material had disadvantageous effect, it is about 0.05% that sulphur content is limited should not surpass, and is no more than about 0.030% preferablely, preferably is no more than about 0.01%.But non-quantitative ground or add the residue form obtain with alloy and have other elements such as copper, vanadium, zirconium, calcium, titanium, aluminium and rare earth metal in molded article.

Directly prepare alloy material and its cast is entered in the mold to be shaped as the element of golf club head.Use existing method with its fusion in air or inert gas atmosphere.Although molten alloy under vacuum condition as by vacuum induction fusion (VIM), can obtain better effect, the VIM cost that is increased does not guarantee the raising of golf club set quality.Can use a kind of simple relatively heat treating castings technology to make alloy material obtain some characteristics.Preferred implementation is: foundry goods was heated about 1-4 hour under about 2000-2300 condition, make the alloy material homogenizing.In air, foundry goods is cooled off from homogenization temperature then.After homogenizing thermal treatment, foundry goods is carried out the solution annealing of grace time to guarantee alloy material complete austenitizing basically at about 1400 °F in about 2000 scopes.For molded shapes as described herein, soaking time is at least about 30 minutes.Foundry goods is cooled to room temperature from the solution annealing temperature fast, preferably in water, oil or polymers soln, quenches, to guarantee producing best effect for the age hardening thermal treatment of carrying out subsequently.Also can implement the forced gas cooling.

After solution treatment, foundry goods is heated to about 900-1100 temperature ranges, made its age hardening, and in air, cooled off then in preferred about 950-1025 about 1-4 of temperature range hours.

Example

A foundry goods example as described herein, its weight percentage is as shown in table 1 below.

Table 1

C??????Mn??????Si??????P????????S????????Cr?????Ni????Mo????Co?????Cu??????B?????N

0.006??＜0.01??＜0.01??＜0.005??＜0.001??10.12??7.01??5.48??10.05??＜0.01??0.003?0.002

All the other compositions of alloy material are iron and common impurity.Embodiment melts in the argon gas atmosphere under atmospheric pressure.Mechanical property to foundry goods embodiment under casting+heat-treat condition is assessed.Assessment result sees following table table 2 for details.

Table 2

Thermal treatment ^*0.2% yield strength UTS % unit elongation %R.A. NTS NTS/UTS hardness

(ksi)?????(ksi)???(4D)?????????(ksi)????????(HRC)

A????????????230.0?????245.7???13.4??????51.6??351.7??1.43??49.5

B????????????233.6?????253.1???13.2??????48.5??346.7??1.37??50.0

C????????????222.8?????253.4???14.1??????54.2??324.3??1.28??49.0

D????????????214.2?????249.7???14.7??????52.4??321.6??1.29??48.0

E????????????201.6?????242.8???16.4??????54.5??297.6??1.23??47.5

F????????????192.0?????236.0???15.5??????51.1??284.5??1.21??47.0

^*For above test, all samples all passes through homogenizing+solid solution-anneal after casting, and technology is as follows

Shown in: 2100 °F were heated 4 hours, and cooled off in air then; 1700 °F were heated 1 hour, and existed then

Quenching-in water.Sample carries out age hardening under condition of different temperatures, as follows:

Treatment process A-950F, 4 hours, air cooling

Treatment process B-975F, 4 hours, air cooling

Treatment process C-1000F, 4 hours, air cooling

Treatment process D-1025F, 4 hours, air cooling

Treatment process E-1050F, 4 hours, air cooling

Treatment process F-1075F, 4 hours, air cooling

Shown in data in the table 2, under about 975 conditions, foundry goods is carried out ageing treatment and can obtain peak value of hardness and be about HRC 50.The result also illustrates: the antivacuum casting sample in the main body invention can obtain to overstep the extreme limit in the broad aging range yield strength value of the about 220ksi of tensile strength and the ductility and the nmotch tensile strength of practicality.

The age hardening temperature of foundry goods correspondence is lower than about 950 °F as described herein.Yet this kind processing is considered to " underaging " thermal treatment, that is to say, the result causes alloy material intensity less than the peak strength that can reach.Through after this " underaging " thermal treatment, alloy material still has effective intensity level.But this feature make alloy material of the present invention and other under lower temperature conditions according to appointment 900-950 precipitation-hardening stainless material that reaches peak strength when carrying out ageing treatment " design compatible ".This feature helps the design of golf club head, but but an end face of malleable band that wherein forms in the precipitation-hardening stainless material of a quality grade be connected with the main body of another precipitation-hardening stainless steel alloy material.When not using multiple material in the golf club head design, alloy material preferably carries out the age hardening processing to reach regulation or specified requirement of strength under the top temperature condition as described herein.

The austenitic existence of the recovery of controlled quantity is favourable to the toughness and the ductility of alloy material of the present invention.Listed the austenite quantity that in last table 1 interalloy material sample, contains in the following table 3.The thermal treatment label is corresponding with the technology of regulation in the last table 2.

Table 3

Thermal treatment	The austenite volumn concentration, %
Thermal treatment	The austenite volumn concentration, %	Trace (＜1) A trace (＜1) B 4 C 5 D 8 E 13 F 18 are processed in homogenising+solution annealing

The data declaration of listing in the table 3: along with the age hardening temperature raises, the austenite quantity that contains in the steel through the age hardening processing increases.

It should be noted that: although grain-size thick a bit (that is, ASTM grain-size No.0-1), this situation is very common in the castingprocesses of golf club head, and alloy material has reached the mechanical property in this regulation.In addition, another feature of the present invention is for having adopted the homogenizing thermal treatment process as mentioned above before solution annealing is handled, and is favourable to cast component like this, comprising the homogeneity of the intensity of improving foundry goods, stretching ductility and performance.Advantage for explanation homogenizing thermal treatment process prepares second of composition weight percentage composition as shown in table 4

Embodiment.

Table 4

C??????Mn??????Si??????P????????S????????Cr?????Ni????Mo????Co?????Cu??????B???????N

0.002??＜0.01??＜0.01??＜0.005??＜0.001??10.09??6.98??5.48??10.96??＜0.01??0.0020??0.005

All the other compositions of alloy material are iron and common impurity.

Table 5

Thermal treatment 0.2% yield strength UTS % unit elongation %RA

(ksi)????????????(ksi)??????(4D)

A ¹?????????????192.0????????????230.8??????9.3?????????15.4

B ²?????????????206.8????????????245.3??????13.4????????42.0

¹Treatment process A:1700 solution annealing handled 1 hour, handled+1025 timeliness 4 hours at quenching-in water subsequently, air cooling.

²Treatment process B:2100 homogenizing handled 4 hours, and air cooling subsequently+1700 solution annealing was handled 1 hour, handled+1025 timeliness 4 hours at quenching-in water subsequently, air cooling.

The data declaration of listing in the table 5: before solution annealing is handled, carried out the heat treated sample of homogenizing than having over-all propertieies such as better intensity and ductility without the heat treated sample of homogenizing.

Term and expression method are used as exemplary term as used herein, and not as restricted term.Use these terms and expression method and do not mean that other equivalently represented method of getting rid of key element, feature or step.Yet, in claim scope of the present invention, can carry out various modifications.

Claims

1, a kind of cast form goods, but make by the stainless steel alloy material of high strength precipitation-hardening, containing following component substantially, its weight percentage is about:

C maximum value 0.1

Mn maximum value 2

Si maximum value 1

P maximum value 0.05

S maximum value 0.05

Cr???????9-13

Ni???????4-8

Mo???????4-8

Co???????8-16

N maximum value 0.1

All the other compositions are essentially iron and common impurity.

2, molded article as claimed in claim 1 is characterized in that, it provides the room temperature that is at least about 220ksi yield strength under casting and heat-treat condition.

3, molded article as claimed in claim 1, but wherein the stainless steel alloy material of precipitation-hardening contains niobium element up to about 1%.

4, molded article as claimed in claim 1, but wherein the stainless steel alloy material of precipitation-hardening contains boron up to about 0.02%.

5, molded article as claimed in claim 1, but wherein the stainless steel alloy material of precipitation-hardening contains following component substantially, and its weight percentage is about:

C maximum value 0.025

Mn maximum value 1

Si maximum value 1

P maximum value 0.04

S maximum value 0.03

Cr???????9.5-12

Ni???????5-8

Mo???????4-8

Co???????8-16

N maximum value 0.025

All the other compositions are essentially iron and common impurity.

6, molded article as claimed in claim 5, but wherein the stainless steel alloy material of precipitation-hardening contains niobium element up to about 1%.

7, molded article as claimed in claim 5, but wherein the stainless steel alloy material of precipitation-hardening contains boron up to about 0.02%.

8, molded article as claimed in claim 1, but wherein the stainless steel alloy material of precipitation-hardening contains following component substantially, and its weight percentage is about:

C maximum value 0.015

Mn maximum value 0.5

Si maximum value 0.5

P maximum value 0.03

S maximum value 0.01

Cr????????10.0-11.5

Ni????????5.5-7.5

Mo????????5-6

Co????????9.5-13.5

N maximum value 0.015

All the other compositions are essentially iron and common impurity.

9, molded article as claimed in claim 8, but wherein the stainless steel alloy material of precipitation-hardening contains niobium element up to about 1%.

10, molded article as claimed in claim 8, but wherein the stainless steel alloy material of precipitation-hardening contains boron up to about 0.02%.

11, a kind of production method of molded article comprises the following steps:

Fusion contains the stainless steel alloy material of following component, and component concentration is represented with weight percentage:

C maximum value 0.1

Mn maximum value 2

Si maximum value 1

P maximum value 0.05

S maximum value 0.05

Cr???????9-13

Ni???????4-8

Mo????????4-8

Co????????8-16

N maximum value 0.1

All the other compositions are essentially iron and common impurity;

The casting of molten alloy material is entered mold, be shaped to cast product;

Cast product is solidified; Then

The thermal treatment cast product is so that this cast product produces age hardening.

12, method as claimed in claim 11, wherein the molten alloy material is cast in air.

13, method as claimed in claim 11, wherein the molten alloy material is cast in inert gas atmosphere.

14, method as claimed in claim 11, it is characterized in that, it may further comprise the steps, promptly cast product is heat-treated, make roughly homogenizing of the composition of cast product and microtexture, after cast product curing is finished, but before cast product age hardening processing is carried out, carry out described homogenizing thermal treatment.

15, method as claimed in claim 14, wherein the homogenizing heat treatment step may further comprise the steps, and promptly under the about 2000-2300 of homogenization temperature °F cast product is heated, and then cast product is cooled off.

16, method as claimed in claim 15, wherein the homogenizing heat treatment step may further comprise the steps, and promptly heats the about 1-4 of cast product hour.

17, method as claimed in claim 15 is characterized in that, it may further comprise the steps, and is about to cast product and is cooled near room temperature from homogenization temperature.

18, method as claimed in claim 11, wherein the age hardening heat treatment step may further comprise the steps:

The heating cast product is so that stainless steel alloy material complete austenitizing basically under a sufficiently high temperature;

Cast product is quickly cooled near room temperature; Then

Under the about 900-1100 of stiffening temperature °F, cast product is heated.

19, method as claimed in claim 18, wherein the austenitizing step of stainless steel alloy material is included under about 1400-2000 the temperature cast product heating 30 minutes at least.

20, method as claimed in claim 18, wherein the heating steps of austenitizing alloy material may further comprise the steps, and promptly under about 950-1025 temperature the austenitizing alloy material is heated, so that the yield strength that is at least about 220ksi to be provided.

21,, wherein heated the about 1-4 of austenitizing alloy material hour as claim 18 or 20 described methods.

22, a kind of golf club head, but make by the stainless steel alloy material of high strength precipitation-hardening, containing following component substantially, its weight percentage is about:

C maximum value 0.1

Mn maximum value 2

Si maximum value 1

P maximum value 0.05

S maximum value 0.05

Cr??????9-13

Ni??????4-8

Mo??????4-8

Co??????8-16

N maximum value 0.1

All the other compositions are essentially iron and common impurity;

Described golf club head adopts following method to be shaped, being about to described alloy material casts in mold, solidify this alloy material, under certain temperature and time conditions, alloy material is fully heat-treated then, so that the yield strength that is at least about 220ksi is provided for described golf club head.