JP2003034843A - High-strength case hardened steel and parts thereof - Google Patents
High-strength case hardened steel and parts thereofInfo
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- JP2003034843A JP2003034843A JP2001352951A JP2001352951A JP2003034843A JP 2003034843 A JP2003034843 A JP 2003034843A JP 2001352951 A JP2001352951 A JP 2001352951A JP 2001352951 A JP2001352951 A JP 2001352951A JP 2003034843 A JP2003034843 A JP 2003034843A
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、機械構造用鋼から
なる部品、例えば、ギヤ、ＣＶＪなどの高強度化が要求
される自動車用鋼部品に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to parts made of steel for machine structures, for example, automotive steel parts such as gears and CVJ which are required to have high strength.
【０００２】[0002]
【従来の技術】ギヤ、ＣＶＪなどの自動車用部品では、
小型軽量化に伴う高強度化が要求される。そこで、１）
ＳＮＣＭなどのＮｉ鋼のように合金元素を添加して高強
度化を図っている。しかし、このように合金元素を添加
して高強度化を図った場合、素材コストが高くなり、冷
間加工性が劣るために冷間鍛造ができず、さらに熱間鍛
造後そのままでは切削できないので焼鈍などの熱処理が
必要となるなどの問題がある。2. Description of the Related Art In automobile parts such as gears and CVJs,
Higher strength is required due to smaller size and lighter weight. So 1)
Alloying elements such as Ni steel such as SNCM are added to increase the strength. However, when alloy elements are added to increase the strength in this way, the material cost increases and cold workability is poor, so cold forging cannot be performed, and furthermore, after hot forging, it cannot be cut as it is. There is a problem that heat treatment such as annealing is required.
【０００３】２）さらに浸炭後、再焼入れを行って結晶
粒の微細化を図って高強度化している。しかし、この場
合も、例えば、ＳＣＭなどの一般鋼を使用した場合で
は、結晶粒の微細化に限界があり十分な高強度化ができ
ない問題がある。2) Further, after carburizing, re-quenching is performed to make the crystal grains finer to increase the strength. However, even in this case, for example, when general steel such as SCM is used, there is a limit to the refinement of crystal grains, and there is a problem that sufficient strength cannot be achieved.
【０００４】３）あるいは、加工処理により結晶粒の微
細化を図って高強度化している。しかしこの場合も、成
形と熱処理を組み合わせるため、成形の難しいものには
適用できないなど部品形状が限定されるなどの問題があ
る。3) Alternatively, the strength is increased by making the crystal grains finer by processing. However, also in this case, since the molding and the heat treatment are combined, there is a problem that the shape of the part is limited such that it cannot be applied to those difficult to mold.
【０００５】また、特開平１０−８１９３８号公報に開
示の方法は、浸炭時のγ粒の粗大化を防ぐものであっ
た。Further, the method disclosed in Japanese Patent Application Laid-Open No. 10-81938 prevents coarsening of γ grains during carburization.
【０００６】[0006]
【発明が解決しようとする課題】本発明が解決しようと
する課題は、従来の上記の問題点を解消することであ
り、浸炭後再焼入れにより、積極的に旧オーステナイト
粒を超微細化して強度を向上させることを目的とする。The problem to be solved by the present invention is to solve the above-mentioned problems of the prior art. By carburizing and re-quenching, the prior austenite grains are positively made ultrafine and the strength is improved. The purpose is to improve.
【０００７】[0007]
【課題を解決するための手段】課題を解決するための本
発明の手段は、請求項１の発明では、質量％で、Ｃ：
０．１０〜０．３５％、Ｓｉ：０．０３〜０．５０％、
Ｍｎ：２．０％以下、Ｔｉ：０．１％超〜０．２％、
Ｎ：０．０１５％以下、Ａｌ：０．００５〜０．０５％
を含有し、残部Ｆｅおよび不可避不純物からなり、旧オ
ーステナイト結晶粒度がＪＩＳ Ｇ０５５１で規定され
ているＮｏ．１１以上まで微細化したマルテンサイト組
織からなることを特徴とする高強度肌焼鋼である。Means for Solving the Problems The means for solving the problems according to the present invention is as follows.
0.10 to 0.35%, Si: 0.03 to 0.50%,
Mn: 2.0% or less, Ti: more than 0.1% to 0.2%,
N: 0.015% or less, Al: 0.005-0.05%
Containing the balance Fe and unavoidable impurities, and having a former austenite grain size defined by JIS G 0551. It is a high-strength case hardening steel characterized by comprising a martensite structure refined to 11 or more.
【０００８】請求項２の発明では、請求項１の手段の鋼
成分に、さらに、質量％で、Ｃｒ：２．０％以下、Ｍ
ｏ：２．０％以下、Ｎｉ：３．０％以下のうち１種又は
２種以上を含有し、残部Ｆｅおよび不可避不純物からな
り、旧オーステナイト結晶粒度がＪＩＳ Ｇ０５５１で
規定されているＮｏ．１１以上まで微細化したマルテン
サイト組織からなることをである。According to the invention of claim 2, in addition to the steel composition of the means of claim 1, in mass%, Cr: 2.0% or less, M
o: 2.0% or less and Ni: 3.0% or less, one or more of them are contained, and the balance Fe and unavoidable impurities are included, and the former austenite grain size is defined by JIS G 0551. It is composed of a martensite structure refined to 11 or more.
【０００９】請求項３の発明では、請求項１の手段の鋼
成分に、さらに、質量％で、Ｖ：０．０２〜０．１０
％、Ｎｂ：０．０２〜０．１０％の１種または２種を含
有し、残部Ｆｅおよび不可避不純物からなり、旧オース
テナイト結晶粒度がＪＩＳ Ｇ０５５１で規定されてい
るＮｏ．１１以上まで微細化したマルテンサイト組織か
らなることを特徴とする高強度肌焼鋼である。According to the invention of claim 3, in addition to the steel component of the means of claim 1, V: 0.02 to 0.10.
%, Nb: 0.02 to 0.10% of 1 type or 2 types, the balance Fe and unavoidable impurities, and the former austenite grain size of No. 1 specified in JIS G 0551. It is a high-strength case hardening steel characterized by comprising a martensite structure refined to 11 or more.
【００１０】請求項４の発明では、請求項１の手段の鋼
成分に、さらに、質量％で、Ｃｒ：２．０％以下、Ｍ
ｏ：２．０％以下、Ｎｉ：３．０％以下のうち１種又は
２種以上を含有し、かつ、さらにＶ：０．０２〜０．１
０％、Ｎｂ：０．０２〜０．１０％の１種または２種を
含有し、残部Ｆｅおよび不可避不純物からなり、旧オー
ステナイト結晶粒度がＪＩＳ Ｇ０５５１で規定されて
いるＮｏ．１１以上まで微細化したマルテンサイト組織
からなることを特徴とする高強度肌焼鋼である。According to the invention of claim 4, in addition to the steel component of the means of claim 1, in mass%, Cr: 2.0% or less, M
o: 2.0% or less, Ni: 3.0% or less, one or more kinds are contained, and V: 0.02 to 0.1.
0%, Nb: 0.02 to 0.10% of 1 type or 2 types, the balance Fe and unavoidable impurities, and the former austenite grain size is defined by JIS G 0551. It is a high-strength case hardening steel characterized by comprising a martensite structure refined to 11 or more.
【００１１】請求項５の発明では、請求項１〜４のいず
れか１項の手段の鋼成分に、さらに、質量％で、Ｂ：
０．０００５〜０．００５％を含有し、残部Ｆｅおよび
不可避不純物からなり、旧オーステナイト結晶粒度がＪ
ＩＳ Ｇ０５５１で規定されているＮｏ．１１以上まで
微細化したマルテンサイト組織からなることを特徴とす
る高強度肌焼鋼である。According to the invention of claim 5, in addition to the steel component of the means of any one of claims 1 to 4, B% in mass%:
0.0005 to 0.005% is contained, the balance is Fe and inevitable impurities, and the former austenite grain size is J
No. specified in IS G0551. It is a high-strength case hardening steel characterized by comprising a martensite structure refined to 11 or more.
【００１２】請求項６の発明では、質量％で、Ｃ：０．
１０〜０．３５％、Ｓｉ：０．０３〜０．５０％、Ｍ
ｎ：２．０％以下、Ｎ：０．０２０％以下、特に０．０
１５％以下、Ａｌ：０．００５〜０．０５％を含有し、
さらにＴｉ：０．０５〜０．２％、Ｖ：０．０２〜０．
１０％、Ｎｂ：０．０２〜０．１％のうち１種ないし２
種以上を含有し、残部Ｆｅおよび不可避不純物からな
り、旧オーステナイト結晶粒度がＪＩＳ Ｇ０５５１で
規定されているＮｏ．１１以上まで微細化したマルテン
サイト組織からなることを特徴とする高強度肌焼鋼であ
る。According to the sixth aspect of the invention, C: 0.
10 to 0.35%, Si: 0.03 to 0.50%, M
n: 2.0% or less, N: 0.020% or less, especially 0.0
15% or less, containing Al: 0.005-0.05%,
Further, Ti: 0.05 to 0.2%, V: 0.02 to 0.
10%, Nb: 0.02 to 0.1% of 1 to 2
No. 1 containing at least one seed and consisting of the balance Fe and unavoidable impurities and having a prior austenite grain size defined by JIS G 0551. It is a high-strength case hardening steel characterized by comprising a martensite structure refined to 11 or more.
【００１３】請求項７の発明では、請求項６の手段の鋼
成分に、さらに、質量％で、Ｃｒ：２．０％以下、Ｍ
ｏ：２．０％以下、Ｎｉ：３．０％以下のうち１種又は
２種以上を含有し、残部Ｆｅおよび不可避不純物からな
り、旧オーステナイト結晶粒度がＪＩＳ Ｇ０５５１で
規定されているＮｏ．１１以上まで微細化したマルテン
サイト組織からなることを特徴とする高強度肌焼鋼であ
る。In the invention of claim 7, in addition to the steel composition of the means of claim 6, in mass%, Cr: 2.0% or less, M
o: 2.0% or less and Ni: 3.0% or less, one or more of them are contained, and the balance Fe and unavoidable impurities are included, and the former austenite grain size is defined by JIS G 0551. It is a high-strength case hardening steel characterized by comprising a martensite structure refined to 11 or more.
【００１４】請求項８の発明では、請求項６または７の
手段の鋼成分に、さらに、質量％で、Ｂ：０．０００５
〜０．００５％を含有し、残部Ｆｅおよび不可避不純物
からなり、旧オーステナイト結晶粒度がＪＩＳ Ｇ０５
５１で規定されているＮｏ．１１以上まで微細化したマ
ルテンサイト組織からなることを特徴とする高強度肌焼
鋼である。According to the invention of claim 8, in addition to the steel composition of the means of claim 6 or 7, B: 0.0005 in mass%.
.About.0.005%, balance Fe and unavoidable impurities, former austenite grain size is JIS G05
No. 51 specified in No. 51. It is a high-strength case hardening steel characterized by comprising a martensite structure refined to 11 or more.
【００１５】請求項９の発明では、請求項１〜８のいず
れか１項の手段の鋼成分に、被削性改善のため、さら
に、質量％で、Ｓ：０．０１〜０．２％、Ｐｂ：０．０
１〜０．３％、Ｂｉ：０．０１〜０．３％、Ｔｅ：０．
０１〜０．２％、Ｓｅ：０．０１〜０．２％、Ｃａ：
０．０００３〜０．０１％、Ｍｇ：０．０００３〜０．
０１％、Ｓｎ：０．０１〜０．２％から選択した１種な
いし２種以上を含有し、残部Ｆｅおよび不可避不純物か
らなり、旧オーステナイト結晶粒度がＪＩＳ Ｇ０５５
１で規定されているＮｏ．１１以上まで微細化したマル
テンサイト組織からなることを特徴とする高強度肌焼鋼
である。According to the invention of claim 9, in order to improve the machinability, the steel composition of the means of any one of claims 1 to 8 is further mass% S: 0.01 to 0.2%. , Pb: 0.0
1 to 0.3%, Bi: 0.01 to 0.3%, Te: 0.
01-0.2%, Se: 0.01-0.2%, Ca:
0.0003-0.01%, Mg: 0.0003-0.
01%, Sn: 0.01 to 0.2%, one or more selected from, and the balance Fe and unavoidable impurities. The former austenite grain size is JIS G055.
No. 1 specified in No. 1 It is a high-strength case hardening steel characterized by comprising a martensite structure refined to 11 or more.
【００１６】請求項１０の発明では、請求項１〜９のい
ずれか１項の手段のマルテンサイト組織の高強度肌焼鋼
からなる鋼部品を、浸炭後、再焼入れを行い、ＪＩＳ
Ｇ０５５１ Ｎｏ．１１以上まで微細化したマルテンサ
イト組織からなるものとしたことを特徴とする高強度肌
焼鋼部品である。In a tenth aspect of the present invention, a steel part made of a high-strength case hardening steel having a martensitic structure according to any one of the first to ninth aspects is carburized and then re-quenched.
G0551 No. It is a high-strength case hardening steel part characterized by comprising a martensite structure refined to 11 or more.
【００１７】本発明の鋼に含有される鋼成分の限定理由
を述べる。なお、％は質量％を示す。The reasons for limiting the steel components contained in the steel of the present invention will be described. In addition,% shows the mass%.
【００１８】Ｃ：Ｃは機械構造用部品として浸炭処理後
の芯部強度を確保するために必要な元素であり、０．１
０％未満ではその効果が十分に得られず、反対に０．３
５％を超えると芯部の靱性を低下させる。そのため含有
量を０．１０〜０．３５％とした。C: C is an element necessary to secure the strength of the core after carburizing as a component for machine structure, and is 0.1
If it is less than 0%, the effect cannot be sufficiently obtained, and on the contrary, 0.3
If it exceeds 5%, the toughness of the core part is deteriorated. Therefore, the content is set to 0.10 to 0.35%.
【００１９】Ｓｉ：Ｓｉは０．０３％未満では脱酸効果
が十分に得られず、０．５０％より過剰に含有させると
加工性を低下させると共に浸炭時の粒界酸化層の形成を
助長し、疲労特性についても低下させる。そのため含有
量を０．０３〜０．５０％とした。Si: If Si is less than 0.03%, a sufficient deoxidizing effect is not obtained, and if it is contained in excess of 0.50%, workability is deteriorated and formation of a grain boundary oxide layer during carburization is promoted. However, it also reduces fatigue characteristics. Therefore, the content is set to 0.03 to 0.50%.
【００２０】Ｍｎ：Ｍｎは焼入性を確保するのに必要な
元素であるが、２．０％を超えると加工性を低下させ
る。そのため、含有量を２．０％以下とした。Mn: Mn is an element necessary to secure hardenability, but if it exceeds 2.0%, workability is deteriorated. Therefore, the content is set to 2.0% or less.
【００２１】Ｔｉ：Ｔｉは鋼中のｆｒｅｅ−Ｎを固定
し、Ｂの焼入性への効果を向上させると共にＴｉ炭化
物、Ｔｉを含有する複合炭化物、Ｔｉ窒化物を微細に析
出させることによって、ＡｌＮに代って浸炭時のオース
テナイト結晶粒度の粗大化を抑制するために必要な元素
である。特に、鋼中に微細分散したナノオーダーのＴｉ
Ｃが結晶粒の成長を抑制する。Ｔｉが０．０５％未満で
はその効果は十分でなく、０．１％を超えることが望ま
しい。しかし、０．２％を超えると析出物の量が過剰と
なり加工性を低下させる。そのため、請求項１の手段で
は含有量を０．１％超〜０．２％とし、請求項６の手段
では含有量を０．０５〜０．２％とした。Ti: Ti fixes free-N in the steel, improves the effect of B on the hardenability, and finely precipitates Ti carbide, Ti-containing composite carbide, and Ti nitride. It is an element necessary for suppressing coarsening of austenite grain size during carburization instead of AlN. In particular, nano-order Ti finely dispersed in steel
C suppresses the growth of crystal grains. If Ti is less than 0.05%, the effect is not sufficient, and it is desirable that Ti exceeds 0.1%. However, if it exceeds 0.2%, the amount of precipitates becomes excessive and the workability deteriorates. Therefore, in the means of claim 1, the content is set to more than 0.1% to 0.2%, and in the means of claim 6, the content is set to 0.05 to 0.2%.
【００２２】Ｖ：Ｖは炭化物を形成し、Ｔｉ同様にオー
ステナイト結晶粒度の粗大化を抑制する効果がある。特
に、鋼中に微細分散したナノオーダーのＶＣが結晶粒の
成長を抑制する。Ｖが０．０２％未満ではその効果が得
られず、０．１０％を超えて含有させると析出物の量が
過剰となり加工性を低下させる。そのため、含有量を
０．０２〜０．１０％とした。V: V forms a carbide and has the effect of suppressing coarsening of the austenite grain size, like Ti. In particular, nano-order VC finely dispersed in steel suppresses the growth of crystal grains. If V is less than 0.02%, the effect cannot be obtained, and if it exceeds 0.10%, the amount of precipitates becomes excessive and the workability is deteriorated. Therefore, the content is set to 0.02 to 0.10%.
【００２３】Ｎｂ：Ｎｂは炭化物あるいは窒化物を形成
し、Ｔｉ同様にオーステナイト結晶粒度の粗大化を抑制
する効果がある。特に、鋼中に微細分散したナノオーダ
ーのＮｂＣが結晶粒の成長を抑制する。Ｎｂが０．０２
％未満ではその効果が得られず、０．１０％を超えて含
有させると析出物の量が過剰となり加工性を低下させ
る。そのため、含有量を０．０２〜０．１０％とした。
なお、請求項３の手段ではＶ、Ｎｂを１種または２種を
含有でき、請求項６の発明ではＴｉ、Ｖ、Ｎｂのうち１
種または２種以上を含有することができる。Nb: Nb forms a carbide or a nitride and, like Ti, has the effect of suppressing coarsening of the austenite grain size. In particular, nano-order NbC finely dispersed in steel suppresses the growth of crystal grains. Nb is 0.02
If it is less than 0.1%, the effect cannot be obtained, and if it exceeds 0.10%, the amount of precipitates becomes excessive and the workability is deteriorated. Therefore, the content is set to 0.02 to 0.10%.
The means of claim 3 can contain one or two kinds of V and Nb, and one of Ti, V and Nb in the invention of claim 6
It may contain one species or two or more species.
【００２４】Ｃｒ：Ｃｒは焼入性および浸炭性を向上さ
せる元素であるが、２．０％を超えて含有させると浸炭
層で粗大な炭化物を形成し、機械的性質、疲労特性を低
下させる。そのため、含有量を２．０％以下とした。Cr: Cr is an element for improving hardenability and carburizing property, but if it exceeds 2.0%, coarse carbides are formed in the carburizing layer and mechanical properties and fatigue properties are deteriorated. . Therefore, the content is set to 2.0% or less.
【００２５】Ｍｏ：Ｍｏは焼入性および靱性を向上させ
る元素であるが、２．０％を超えて含有させると圧延あ
るいは鍛造後にベイナイトやマルテンサイト組織となり
加工性を著しく低下させ、コストアップにつながる。そ
のため、含有量を２．０％以下とした。Mo: Mo is an element that improves hardenability and toughness, but if it is contained in excess of 2.0%, it becomes bainite or martensite structure after rolling or forging, which significantly lowers the workability and raises the cost. Connect Therefore, the content is set to 2.0% or less.
【００２６】Ｎｉ：Ｎｉは焼入性および靱性を向上させ
る元素であるが、３．０％を超えて含有させると圧延あ
るいは鍛造後にベイナイトやマルテンサイト組織となり
加工性を著しく低下させ、コストアップにつながる。そ
のため、含有量を３．０％以下とした。なお、Ｃｒ、Ｍ
ｏ、Ｎｉはそれらのうち１種または２種以上を含有する
ことができる。Ni: Ni is an element that improves hardenability and toughness, but if it is contained in excess of 3.0%, it becomes bainite or martensite structure after rolling or forging, which significantly lowers workability, resulting in cost increase. Connect Therefore, the content is set to 3.0% or less. In addition, Cr, M
o and Ni can contain 1 type (s) or 2 or more types among them.
【００２７】Ｎ：Ｎは０．０１５％を超えて、殊に０．
０２０％を超えて含有するとＴｉＮが増加し、疲労特性
に悪影響を及ぼす。そのため、請求項６の発明では、含
有量を０．０２０％、特に請求項１の発明では、０．０
１５％以下とした。N: N exceeds 0.015%, in particular 0.
If the content exceeds 020%, TiN increases, and the fatigue properties are adversely affected. Therefore, in the invention of claim 6, the content is 0.020%, and particularly in the invention of claim 1, 0.0
It was set to 15% or less.
【００２８】Ａｌ：Ａｌは脱酸剤として使用される元素
であり、０．００５％未満ではその効果が十分でなく、
０．０５％を超えるとアルミナ系酸化物が増加し疲労特
性、加工性を低下させる。そのため、含有量を０．００
５〜０．０５％とした。Al: Al is an element used as a deoxidizer, and if it is less than 0.005%, its effect is not sufficient.
If it exceeds 0.05%, the amount of alumina-based oxide increases, and the fatigue properties and workability are deteriorated. Therefore, the content is 0.00
It was set to 5 to 0.05%.
【００２９】Ｂ：Ｂは極く微量の添加によって鋼の焼入
性を著しく向上させる元素であり、任意に選択的に添加
できる元素である。しかし、０．０００５％未満ではそ
の効果は十分でなく、０．００５％を超えると逆に焼入
性を低下させる。そのため、含有量を０．０００５〜
０．００５％とした。B: B is an element that remarkably improves the hardenability of steel by the addition of a very small amount, and is an element that can be selectively added arbitrarily. However, if it is less than 0.0005%, the effect is not sufficient, and if it exceeds 0.005%, the hardenability is deteriorated. Therefore, the content is 0.0005-
It was set to 0.005%.
【００３０】被削性の改善元素として、さらに、Ｓ：
０．０１〜０．２％、Ｐｂ：０．０１〜０．３％、Ｂ
ｉ：０．０１〜０．３％、Ｔｅ：０．０１〜０．２％、
Ｓｅ：０．０１〜０．２％、Ｃａ：０．０００３〜０．
０１％、Ｍｇ：０．０００３〜０．０１％、Ｓｎ：０．
０１〜０．２％から選択した１種ないし２種以上を含有
することができる。これらの元素は、その下限値以下で
は十分な被削性改善の効果はなく、その上限値を超える
と逆に靱性を低下するので上限値以下とする。As elements for improving machinability, S:
0.01-0.2%, Pb: 0.01-0.3%, B
i: 0.01 to 0.3%, Te: 0.01 to 0.2%,
Se: 0.01-0.2%, Ca: 0.0003-0.
01%, Mg: 0.0003 to 0.01%, Sn: 0.
One or more selected from 01 to 0.2% can be contained. Below these lower limits, these elements have no sufficient machinability-improving effect, and above their upper limits conversely lower toughness, so they are made below the upper limit.
【００３１】本発明の作用について述べると、本発明は
鋼の強度を向上させるために、旧オーステナイト粒がＪ
ＩＳ Ｇ０５５１で規定されているＮｏ．１１以上に極
めて微細化したマルテンサイト組織の鋼を使用する。こ
れによって鋼の破壊起点が粒界破壊から、粒内破壊へと
移行し、曲げ強度、衝撃特性が向上する。The operation of the present invention will be described. In the present invention, in order to improve the strength of steel, the former austenite grains are J
No. specified in IS G0551. Steel with a martensitic structure extremely refined to 11 or more is used. As a result, the fracture starting point of steel shifts from intergranular fracture to intragranular fracture, and bending strength and impact properties are improved.
【００３２】本発明の上記の鋼からなる鋼部品は、さら
に浸炭後、再焼入れを行うことが特に重要であり、通常
の浸炭焼入れのままでは、超微細化しない。すなわち、
浸炭焼入れし、前組織をマルテンサイト（またはベイナ
イト）にした状態で焼入れすると超微細化する。It is particularly important that the steel part made of the above steel according to the present invention is further carburized and then re-quenched, and if it is normally carburized and quenched, it does not become ultra-fine. That is,
If it is carburized and quenched and the previous structure is martensite (or bainite), it becomes ultra-fine.
【００３３】ここでは、マルテンサイト（またはベイナ
イト）は再焼入れの加熱時にオーステナイトに一旦なる
が、このオーステナイト生成サイトが多いため、いたる
ところからオーステナイト粒ができる。このオーステナ
イト粒を微細分散したＴｉＣがピンニングし、結晶粒の
成長を止める。その状態から焼き入れされるため、超微
細化したマルテンサイト組織ができる。Here, the martensite (or bainite) once becomes austenite at the time of heating for re-quenching, but since there are many austenite forming sites, austenite grains are formed everywhere. The TiC in which the austenite grains are finely dispersed is pinned to stop the growth of crystal grains. Since quenching is performed from that state, an ultrafine martensite structure is formed.
【００３４】すなわち、Ｔｉを添加した鋼（出願人の開
発した鋼で、特開平１０−８１９３８号に開示の鋼）を
旧オーステナイト結晶粒度がＪＩＳ Ｇ０５５１で規定
されているＮｏ．１１以上まで微細化したマルテンサイ
ト組織からなる鋼とし、この鋼からなる鋼部品に、特
に、浸炭後、再焼入れすることにより、結晶粒が超微細
化することを利用している。一般鋼（ＳＣＭなど）も再
焼入れすることにより微細化するが、粒度Ｎｏ．１１未
満程度が限界であり、また、混粒が発生し易い。That is, a steel containing Ti (a steel developed by the applicant and disclosed in Japanese Patent Application Laid-Open No. 10-81938) has a former austenite grain size of No. 5 specified in JIS G 0551. A steel having a martensite structure refined to 11 or more is used, and it is utilized that a steel part made of this steel, in particular, is subjected to carburizing and then re-quenching to make the crystal grains ultra-fine. General steel (such as SCM) is also refined by re-quenching, but grain size No. There is a limit of less than 11 and mixed particles are likely to occur.
【００３５】Ｔｉを添加した鋼の場合、特開平１０−８
１９３８号に開示の発明では、上記のＳＣＭなどと同様
に、結晶粒の粗大化は阻止されて高強度となっている
が、粒度はＮｏ．１１未満程度である。これに対し、本
発明では、旧オーステナイト結晶粒度がＪＩＳ Ｇ０５
５１で規定されているＮｏ．１１以上まで微細化したマ
ルテンサイト組織からなる鋼とし、このＴｉ添加の鋼か
らなる鋼部品を、浸炭後、再焼入れすることにより、ナ
ノオーダーのＴｉＣが微細に分散し、結晶粒の成長を止
める（ピンニング効果）。これにより一般鋼では達成で
きなかった領域の結晶粒度Ｎｏ．１１を超えて超微細化
することが可能となり、この結晶粒の超微細化により、
さらに高強度化が図れるものである。In the case of steel containing Ti, the method disclosed in JP-A-10-8
In the invention disclosed in Japanese Patent No. 1938, similarly to the above SCM and the like, coarsening of crystal grains is prevented and high strength is achieved, but the grain size is No. It is less than about 11. On the contrary, in the present invention, the former austenite grain size is JIS G05.
No. 51 specified in No. 51. A steel with a martensite structure refined to 11 or more is used, and the steel parts made of this Ti-added steel are carburized and then re-quenched, whereby nano-order TiC is finely dispersed and the growth of crystal grains is stopped. (Pinning effect). As a result, the grain size No. of the region that could not be achieved with general steel was obtained. It becomes possible to make ultra-fine beyond 11, and by making the crystal grains ultra-fine,
The strength can be further increased.
【００３６】これにより、Ｎｉなどの高価な元素を用い
なくとも、機械的性質（曲げ強度、靱性など）を大幅に
向上させることができる。また加工熱処理ではないの
で、全ての部品に適用できる。As a result, the mechanical properties (flexural strength, toughness, etc.) can be greatly improved without using expensive elements such as Ni. Since it is not a thermomechanical treatment, it can be applied to all parts.
【００３７】[0037]
【発明の実施の形態】本発明の請求項１〜９の実施の形
態の鋼は、表１および表２の発明鋼のＮｏ．９〜Ｎｏ．
３３に示す鋼組成で、旧オーステナイト粒がＪＩＳ Ｇ
０５５１で規定されているＮｏ．１１以上に極めて微細
化したマルテンサイト組織の鋼からなり、ナノオーダー
のＴｉＣを微細分散したＴｉ添加の鋼である。請求項１
０の実施の形態の鋼部品は、上記のＴｉ添加の鋼からな
る鋼部品を、浸炭後、再焼入れして結晶粒をＪＩＳ Ｇ
０５５１ Ｎｏ．１１以上まで微細化したマルテンサイ
ト組織からなるものとしたものである。BEST MODE FOR CARRYING OUT THE INVENTION The steels according to the embodiments of claims 1 to 9 of the present invention are the invention steel Nos. 9-No.
In the steel composition shown in No. 33, the former austenite grains are JIS G
No. specified in 0551. It is a steel with a martensite structure that is extremely refined to 11 or more and Ti-added steel in which nano-order TiC is finely dispersed. Claim 1
In the steel part of the embodiment of No. 0, the steel part made of the above-mentioned Ti-added steel is carburized and then re-quenched to obtain crystal grains according to JIS G.
0551 No. It has a martensite structure refined to 11 or more.
【００３８】[0038]
【実施例】表１および表２に示す比較鋼および発明鋼の
供試材を１００ｋｇ真空溶解炉にて溶製してなる鋼片を
１２５０℃に加熱してφ２０ｍｍの棒鋼に鍛伸した。こ
の場合、微細なＴｉ、Ｎｂ、Ｖ炭化物を析出させるため
には鋼片を１２５０〜１４００℃で圧延する。さらに棒
線に圧延するときは、Ａｃ3〜１０５０℃で圧延する。
次いで、９５０℃で仕上げ鍛伸して、さらにφ１４ｍｍ
×２１ｍｍＨの円柱試験片に加工した後、９３０℃で６
時間保持して浸炭焼入れした後、８５０℃で０．５時間
保持して再焼入れし、１８０℃に１．５時間保持して焼
戻しする。EXAMPLES Steel pieces prepared by melting the test materials of the comparative steels and the invention steels shown in Tables 1 and 2 in a 100kg vacuum melting furnace were heated to 1250 ° C. and forged into φ20 mm steel bars. In this case, in order to precipitate fine Ti, Nb, and V carbides, the steel slab is rolled at 1250 to 1400 ° C. Further, when rolling into a bar wire, rolling is performed at Ac 3 to 1050 ° C.
Next, finish forging at 950 ° C and further φ14mm
After processing into a cylinder test piece of × 21 mmH, it is processed at 930 ° C for 6
After holding for a period of time to perform carburizing and quenching, it is held at 850 ° C. for 0.5 hour to be re-quenched, and held at 180 ° C. for 1.5 hour to be tempered.
【００３９】[0039]
【表１】 [Table 1]
【００４０】[0040]
【表２】 [Table 2]
【００４１】上記で得られた試験片の結晶粒をＪＩＳ
ＧＯ５５１の規定により測定し、その結果を表３および
表４に示す。本発明鋼のＮｏ．９〜３３は、比較鋼のＮ
ｏ．１〜８に比し粒度Ｎｏ．は高く、いずれもＮｏ．１
１以上で、結晶粒が超微粒であることがわかる。The crystal grains of the test piece obtained above were measured according to JIS.
It was measured according to the rules of GO551, and the results are shown in Tables 3 and 4. The steel of the present invention No. 9 to 33 are N of comparative steels
o. The particle size No. Is high, and both are No. 1
It can be seen that when it is 1 or more, the crystal grains are ultrafine grains.
【００４２】本発明に係る発明鋼Ｎｏ．１０からなる鋼
部品と比較例に係る比較鋼Ｎｏ．３および比較鋼Ｎｏ．
８からなる鋼部品の浸炭後の再焼入れした結晶粒径の４
００倍で示す顕微鏡写真を図１に示す。発明鋼Ｎｏ．１
０の結晶粒径が、比較鋼Ｎｏ．３および比較鋼Ｎｏ．８
の結晶粒径に比して極めて微細であることがわかる。Invention Steel No. 1 according to the present invention. No. 10 steel part and comparative steel No. 3 and comparative steel No.
Recarburized grain size 4 after carburizing steel parts consisting of 4
A micrograph shown at 00 times is shown in FIG. Invention Steel No. 1
The crystal grain size of 0 is comparative steel No. 3 and comparative steel No. 8
It is understood that the particle size is extremely fine compared to the crystal grain size of.
【００４３】さらに、亀裂発生荷重と破断荷重を評価す
るために、静的３点曲げ試験を行い、その結果を比較鋼
Ｎｏ．１に対する比で表３に示す。静的３点曲げ試験
は、浸炭後、再焼入れした角１０ｍｍ×長さ７０ｍｍの
試験片に、２ｍｍＶノッチを設け、スパン間距離５０ｍ
ｍで行った。本発明鋼の供試材のＮｏ．９〜３３は、比
較鋼の供試材のＮｏ．１〜８に比し初期亀裂発生荷重お
よび亀裂発生荷重で優れており、特にＮｏ．１に比し２
倍以上の初期亀裂発生荷重で優れていることが分かる。
さらに発明鋼Ｎｏ．１０と比較鋼Ｎｏ．３の静曲げ試験
の破壊起点部と伝播部のＳＥＭ写真を図２に示す。同図
において、比較鋼Ｎｏ．３では起点部も伝播部も粒界破
壊であるが、発明鋼Ｎｏ．１０では破壊起点が粒界破壊
から、粒内破壊へ移行していることがわかる。Further, in order to evaluate the crack initiation load and the fracture load, a static three-point bending test was carried out, and the results are shown as comparative steel No. The ratio to 1 is shown in Table 3. In the static three-point bending test, after carburizing, a requenched test piece of 10 mm square and 70 mm long is provided with a 2 mm V notch, and a span distance is 50 m.
I went in m. No. of the test material of the present invention steel Nos. 9 to 33 are sample materials of comparative steels. Excellent in initial cracking load and cracking load as compared with Nos. 1 to 8, and particularly No. 2 compared to 1
It can be seen that the initial crack initiation load of more than double is excellent.
Further, invention steel No. No. 10 and comparative steel No. FIG. 2 shows SEM photographs of the fracture starting portion and the propagation portion in the static bending test of No. 3. In the figure, comparative steel No. In the case of the invention steel No. 3, although the starting portion and the propagating portion are intergranular fractures in No. 3, It can be seen that in No. 10, the fracture starting point is changed from intergranular fracture to intragranular fracture.
【００４４】[0044]
【表３】 [Table 3]
【００４５】また、さらに衝撃値を評価するために、浸
炭後、再焼入れした角１０ｍｍ×長さ５５ｍｍの試験片
に、１０ＲＣ ２ｍｍノッチを設けて、シャルピー衝撃
試験を行い、その結果を比較鋼Ｎｏ．１に対する比で表
４に示す。本発明鋼の供試材のＮｏ．９〜３３は、比較
鋼の供試材のＮｏ．１〜８に比し格段に衝撃値で優れて
おり、特にＮｏ．１に比し２倍以上の衝撃値で優れてい
ることが分かる。Further, in order to further evaluate the impact value, a Charpy impact test was carried out by providing a 10 RC 2 mm notch on a test piece having a corner of 10 mm and a length of 55 mm which was re-quenched after carburizing, and the Charpy impact test was conducted. ． The ratio to 1 is shown in Table 4. No. of the test material of the present invention steel Nos. 9 to 33 are sample materials of comparative steels. Compared to Nos. 1 to 8, the impact value is remarkably excellent. It can be seen that the impact value is more than twice as high as that of 1.
【００４６】[0046]
【表４】 [Table 4]
【００４７】[0047]
【発明の効果】以上説明したように、本発明は、Ｔｉを
添加した鋼を、旧オーステナイト結晶粒度がＪＩＳ Ｇ
０５５１で規定されているＮｏ．１１以上まで微細化し
たマルテンサイト組織からなる高強度肌焼鋼とし、さら
にこの鋼から鋼部品とし、浸炭後、再焼入れをすること
で、結晶粒度をＪＩＳ Ｇ０５５１ Ｎｏ．１１以上ま
で微細化したマルテンサイト組織からなるものが得ら
れ、自動車用部品として従来にない高強度の肌焼鋼部品
が得られる。As described above, according to the present invention, the Ti-added steel has a former austenite grain size of JIS G
No. specified in 0551. A high-strength case-hardening steel composed of a martensite structure refined to 11 or more is further used as a steel part. After carburizing and re-quenching, the grain size is determined according to JIS G0551 No. A martensite structure refined to 11 or more can be obtained, and a high-strength case hardening steel part which has never been obtained as an automobile part can be obtained.
【図１】本発明鋼Ｎｏ．１０からなる鋼部品と比較例に
係る比較鋼Ｎｏ．３および比較鋼Ｎｏ．８からなる鋼部
品の浸炭後の再焼入れした結晶粒径の顕微鏡写真を示
す。BRIEF DESCRIPTION OF THE DRAWINGS FIG. No. 10 steel part and comparative steel No. 3 and comparative steel No. 8 shows a micrograph of the re-quenched crystal grain size of a steel part consisting of 8 after carburization.
【図２】発明鋼Ｎｏ．１０と比較鋼Ｎｏ．３の静曲げ試
験の破壊起点部と伝播部のＳＥＭ写真を示す。FIG. 2 Inventive steel No. No. 10 and comparative steel No. The SEM photograph of the fracture starting point part and propagation part of the static bending test of 3 is shown.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ テーマコート゛(参考） Ｆ１６Ｈ 55/06 Ｆ１６Ｈ 55/06 ─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. 7 Identification code FI theme code (reference) F16H 55/06 F16H 55/06
Claims (10)
Ｓｉ：０．０３〜０．５０％、Ｍｎ：２．０％以下、Ｔ
ｉ：０．１％超〜０．２％、Ｎ：０．０１５％以下、Ａ
ｌ：０．００５〜０．０５％を含有し、残部Ｆｅおよび
不可避不純物からなり、旧オーステナイト結晶粒度がＪ
ＩＳ Ｇ０５５１で規定されているＮｏ．１１以上まで
微細化したマルテンサイト組織からなることを特徴とす
る高強度肌焼鋼。1. C: 0.10 to 0.35% by mass%
Si: 0.03 to 0.50%, Mn: 2.0% or less, T
i: more than 0.1% to 0.2%, N: 0.015% or less, A
1: 0.005 to 0.05%, balance Fe and unavoidable impurities, former austenite grain size J
No. specified in IS G0551. A high-strength case hardening steel characterized by comprising a martensite structure refined to 11 or more.
％で、Ｃｒ：２．０％以下、Ｍｏ：２．０％以下、Ｎ
ｉ：３．０％以下のうち１種又は２種以上を含有し、残
部Ｆｅおよび不可避不純物からなり、旧オーステナイト
結晶粒度がＪＩＳ Ｇ０５５１で規定されているＮｏ．
１１以上まで微細化したマルテンサイト組織からなるこ
とを特徴とする高強度肌焼鋼。2. The steel composition according to claim 1, further comprising Cr: 2.0% or less, Mo: 2.0% or less, and N in mass%.
i: One or more of 3.0% or less is contained, the balance is Fe and unavoidable impurities, and the former austenite grain size is No. specified by JIS G0551.
A high-strength case hardening steel characterized by comprising a martensite structure refined to 11 or more.
％で、Ｖ：０．０２〜０．１０％、Ｎｂ：０．０２〜
０．１０％の１種または２種を含有し、残部Ｆｅおよび
不可避不純物からなり、旧オーステナイト結晶粒度がＪ
ＩＳ Ｇ０５５１で規定されているＮｏ．１１以上まで
微細化したマルテンサイト組織からなることを特徴とす
る高強度肌焼鋼。3. The steel composition according to claim 1, further comprising V: 0.02 to 0.10% and Nb: 0.02 in mass%.
0.10% of 1 type or 2 types is contained, the balance is Fe and unavoidable impurities, and the former austenite grain size is J
No. specified in IS G0551. A high-strength case hardening steel characterized by comprising a martensite structure refined to 11 or more.
％で、Ｃｒ：２．０％以下、Ｍｏ：２．０％以下、Ｎ
ｉ：３．０％以下のうち１種又は２種以上を含有し、か
つ、さらにＶ：０．０２〜０．１０％、Ｎｂ：０．０２
〜０．１０％の１種または２種を含有し、残部Ｆｅおよ
び不可避不純物からなり、旧オーステナイト結晶粒度が
ＪＩＳ Ｇ０５５１で規定されているＮｏ．１１以上ま
で微細化したマルテンサイト組織からなることを特徴と
する高強度肌焼鋼。4. The steel composition according to claim 1, further comprising Cr: 2.0% or less, Mo: 2.0% or less, and N in mass%.
i: One or more of 3.0% or less, and V: 0.02 to 0.10%, Nb: 0.02
.About.0.10% of 1 type or 2 types, the balance Fe and unavoidable impurities, and the former austenite grain size of No. 1 specified in JIS G 0551. A high-strength case hardening steel characterized by comprising a martensite structure refined to 11 or more.
成分に、さらに、質量％で、Ｂ：０．０００５〜０．０
０５％を含有し、残部Ｆｅおよび不可避不純物からな
り、旧オーステナイト結晶粒度がＪＩＳ Ｇ０５５１で
規定されているＮｏ．１１以上まで微細化したマルテン
サイト組織からなることを特徴とする高強度肌焼鋼。5. The steel composition according to claim 1, further comprising B: 0.0005 to 0.0 in mass%.
No. No. specified by JIS G 0551, the former austenite grain size is defined by JIS No. 05551. A high-strength case hardening steel characterized by comprising a martensite structure refined to 11 or more.
Ｓｉ：０．０３〜０．５０％、Ｍｎ：２．０％以下、
Ｎ：０．０２０％以下、Ａｌ：０．００５〜０．０５％
を含有し、さらにＴｉ：０．０５〜０．２％、Ｖ：０．
０２〜０．１０％、Ｎｂ：０．０２〜０．１％のうち１
種ないし２種以上を含有し、残部Ｆｅおよび不可避不純
物からなり、旧オーステナイト結晶粒度がＪＩＳ Ｇ０
５５１で規定されているＮｏ．１１以上まで微細化した
マルテンサイト組織からなることを特徴とする高強度肌
焼鋼。6. C: 0.10 to 0.35% by mass%,
Si: 0.03 to 0.50%, Mn: 2.0% or less,
N: 0.020% or less, Al: 0.005-0.05%
In addition, Ti: 0.05 to 0.2%, V: 0.
02-0.10%, Nb: 0.02-0.1% of 1%
1 to 2 or more, the balance Fe and unavoidable impurities, and the former austenite grain size is JIS G0
No. stipulated in No. 551. A high-strength case hardening steel characterized by comprising a martensite structure refined to 11 or more.
％で、Ｃｒ：２．０％以下、Ｍｏ：２．０％以下、Ｎ
ｉ：３．０％以下のうち１種又は２種以上を含有し、残
部Ｆｅおよび不可避不純物からなり、旧オーステナイト
結晶粒度がＪＩＳ Ｇ０５５１で規定されているＮｏ．
１１以上まで微細化したマルテンサイト組織からなるこ
とを特徴とする高強度肌焼鋼。7. The steel composition according to claim 6, further comprising Cr: 2.0% or less, Mo: 2.0% or less, and N in mass%.
i: One or more of 3.0% or less is contained, the balance is Fe and unavoidable impurities, and the former austenite grain size is No. specified by JIS G0551.
A high-strength case hardening steel characterized by comprising a martensite structure refined to 11 or more.
らに、質量％で、Ｂ：０．０００５〜０．００５％を含
有し、残部Ｆｅおよび不可避不純物からなり、旧オース
テナイト結晶粒度がＪＩＳ Ｇ０５５１で規定されてい
るＮｏ．１１以上まで微細化したマルテンサイト組織か
らなることを特徴とする高強度肌焼鋼。8. The steel composition according to claim 6 or 7, further containing B: 0.0005 to 0.005% by mass%, the balance being Fe and inevitable impurities, and having a former austenite grain size. The No. specified in JIS G0551. A high-strength case hardening steel characterized by comprising a martensite structure refined to 11 or more.
成分に、被削性改善のため、さらに、質量％で、Ｓ：
０．０１〜０．２％、Ｐｂ：０．０１〜０．３％、Ｂ
ｉ：０．０１〜０．３％、Ｔｅ：０．０１〜０．２％、
Ｓｅ：０．０１〜０．２％、Ｃａ：０．０００３〜０．
０１％、Ｍｇ：０．０００３〜０．０１％、Ｓｎ：０．
０１〜０．２％から選択した１種ないし２種以上を含有
し、残部Ｆｅおよび不可避不純物からなり、旧オーステ
ナイト結晶粒度がＪＩＳ Ｇ０５５１で規定されている
Ｎｏ．１１以上まで微細化したマルテンサイト組織から
なることを特徴とする高強度肌焼鋼。9. The steel composition according to claim 1, further comprising S: in mass% to improve machinability.
0.01-0.2%, Pb: 0.01-0.3%, B
i: 0.01 to 0.3%, Te: 0.01 to 0.2%,
Se: 0.01-0.2%, Ca: 0.0003-0.
01%, Mg: 0.0003 to 0.01%, Sn: 0.
It contains one or more selected from 01 to 0.2%, consists of the balance Fe and unavoidable impurities, and has a former austenite grain size of No. 1 specified in JIS G 0551. A high-strength case hardening steel characterized by comprising a martensite structure refined to 11 or more.
マルテンサイト組織の高強度肌焼鋼からなる鋼部品を、
浸炭後、再焼入れを行い、ＪＩＳ Ｇ０５５１ Ｎｏ．
１１以上まで微細化したマルテンサイト組織からなるも
のとしたことを特徴とする高強度肌焼鋼部品。10. A steel part made of a high-strength case hardening steel having a martensitic structure according to claim 1,
After carburizing, re-quenching is performed, and JIS G0551 No.
A high-strength case hardening steel part characterized by comprising a martensite structure refined to 11 or more.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001352951A JP2003034843A (en) | 2001-05-14 | 2001-11-19 | High-strength case hardened steel and parts thereof |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001143672 | 2001-05-14 | ||
| JP2001-143672 | 2001-05-14 | ||
| JP2001352951A JP2003034843A (en) | 2001-05-14 | 2001-11-19 | High-strength case hardened steel and parts thereof |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2006000280A Division JP2006152445A (en) | 2001-05-14 | 2006-01-04 | High strength case hardened steel and parts thereof |
| JP2006000281A Division JP2006169637A (en) | 2001-05-14 | 2006-01-04 | Method for manufacturing high-strength carburized part |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2003034843A true JP2003034843A (en) | 2003-02-07 |
Family
ID=26615063
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001352951A Pending JP2003034843A (en) | 2001-05-14 | 2001-11-19 | High-strength case hardened steel and parts thereof |
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| Country | Link |
|---|---|
| JP (1) | JP2003034843A (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006291335A (en) * | 2005-04-14 | 2006-10-26 | Kobe Steel Ltd | Steel for case hardening having excellent high temperature carburizing characteristic and workability |
| JP2007016271A (en) * | 2005-07-06 | 2007-01-25 | Kobe Steel Ltd | Steel for induction hardening for pinion having excellent machinability, method for producing the same, and pinion having excellent bending fatigue property |
| JP2007056296A (en) * | 2005-08-23 | 2007-03-08 | Ntn Corp | Method for producing carburized parts for constant velocity joint |
| JP2008297618A (en) * | 2007-06-02 | 2008-12-11 | Sanyo Special Steel Co Ltd | Method for manufacturing carburized steel part excellent in indentation resistance |
| JP2010007117A (en) * | 2008-06-25 | 2010-01-14 | Sanyo Special Steel Co Ltd | Method for manufacturing high-strength carburized component |
| WO2014104113A1 (en) * | 2012-12-28 | 2014-07-03 | 新日鐵住金株式会社 | Steel for carburizing |
| US8980022B2 (en) | 2009-01-16 | 2015-03-17 | Nippon Steel & Sumitomo Metal Corporation | Case hardening steel, carburized component, and manufacturing method of case hardening steel |
| JP2016188421A (en) * | 2015-03-30 | 2016-11-04 | 株式会社神戸製鋼所 | Carburized component |
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| JPH08199303A (en) * | 1995-01-24 | 1996-08-06 | Daido Steel Co Ltd | Steel prevented from coarsening of crystal grain |
| JP2000063983A (en) * | 1998-08-24 | 2000-02-29 | Sanyo Special Steel Co Ltd | Case hardening steel excellent in bending strength |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JPH0892690A (en) * | 1994-09-27 | 1996-04-09 | Sumitomo Metal Ind Ltd | Carburized parts excellent in fatigue resistance and its production |
| JPH08199303A (en) * | 1995-01-24 | 1996-08-06 | Daido Steel Co Ltd | Steel prevented from coarsening of crystal grain |
| JP2000063983A (en) * | 1998-08-24 | 2000-02-29 | Sanyo Special Steel Co Ltd | Case hardening steel excellent in bending strength |
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006291335A (en) * | 2005-04-14 | 2006-10-26 | Kobe Steel Ltd | Steel for case hardening having excellent high temperature carburizing characteristic and workability |
| JP2007016271A (en) * | 2005-07-06 | 2007-01-25 | Kobe Steel Ltd | Steel for induction hardening for pinion having excellent machinability, method for producing the same, and pinion having excellent bending fatigue property |
| JP4502892B2 (en) * | 2005-07-06 | 2010-07-14 | 株式会社神戸製鋼所 | Steel for induction hardening for pinions with excellent machinability, manufacturing method thereof, and pinion with excellent bending fatigue characteristics |
| JP2007056296A (en) * | 2005-08-23 | 2007-03-08 | Ntn Corp | Method for producing carburized parts for constant velocity joint |
| JP2008297618A (en) * | 2007-06-02 | 2008-12-11 | Sanyo Special Steel Co Ltd | Method for manufacturing carburized steel part excellent in indentation resistance |
| JP2010007117A (en) * | 2008-06-25 | 2010-01-14 | Sanyo Special Steel Co Ltd | Method for manufacturing high-strength carburized component |
| US8980022B2 (en) | 2009-01-16 | 2015-03-17 | Nippon Steel & Sumitomo Metal Corporation | Case hardening steel, carburized component, and manufacturing method of case hardening steel |
| WO2014104113A1 (en) * | 2012-12-28 | 2014-07-03 | 新日鐵住金株式会社 | Steel for carburizing |
| CN104884660A (en) * | 2012-12-28 | 2015-09-02 | 新日铁住金株式会社 | Steel for carburizing |
| JP5862802B2 (en) * | 2012-12-28 | 2016-02-16 | 新日鐵住金株式会社 | Carburizing steel |
| CN104884660B (en) * | 2012-12-28 | 2017-03-15 | 新日铁住金株式会社 | Carburizing steel |
| KR101745224B1 (en) | 2012-12-28 | 2017-06-08 | 신닛테츠스미킨 카부시키카이샤 | Steel for carburizing |
| JP2016188421A (en) * | 2015-03-30 | 2016-11-04 | 株式会社神戸製鋼所 | Carburized component |
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