JPS61272349A - Bearing steel - Google Patents
Bearing steelInfo
- Publication number
- JPS61272349A JPS61272349A JP11426585A JP11426585A JPS61272349A JP S61272349 A JPS61272349 A JP S61272349A JP 11426585 A JP11426585 A JP 11426585A JP 11426585 A JP11426585 A JP 11426585A JP S61272349 A JPS61272349 A JP S61272349A
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- weight
- bearing steel
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- fatigue life
- Prior art date
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Abstract
Description
【発明の詳細な説明】
り発明の目的]
(産業上の利用分野)
この発明は、とくに転がり疲れ寿命に著しく優れた軸受
の素材として利用される高炭素クロム軸受鋼に関するも
のである。[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a high carbon chromium bearing steel that is used as a material for bearings, which has particularly excellent rolling fatigue life.
(従来の技術)
一般に、機械構造用部品は高い疲れ強さを要求されるの
で、材料の選択に配慮する必要があるが、とくに軸受等
の転がり疲れ強さが重視される機械構造用部品には、J
IS G 4805に制定された高炭素クロム軸受
鋼(SUJI〜5)が素材として用いられることが多い
。(Prior art) In general, mechanical structural parts are required to have high fatigue strength, so consideration must be given to the selection of materials, but this is especially true for mechanical structural parts such as bearings where rolling fatigue strength is important. Ha, J
High carbon chromium bearing steel (SUJI~5) specified in IS G 4805 is often used as the material.
このような軸受鋼において、これを素材とする軸受の転
がり疲れ強さを増大させてその寿命を延長させるように
するためには、鋼中に不可避的、に含有される代表的な
非金属介在物、すなわち、A1203 、S i02
、MnS 、TiN等の量を抑制することが必要で
あり、そのためには、鋼中の0.S、Ti、N等の含有
量を極力低減させることが重要である。In order to increase the rolling fatigue strength and extend the life of bearings made of bearing steel, typical non-metallic inclusions that are unavoidably contained in the steel must be added. objects, i.e. A1203, S i02
, MnS, TiN, etc., and for this purpose, it is necessary to suppress the amount of 0. It is important to reduce the content of S, Ti, N, etc. as much as possible.
さらに、鋼中に含まれるM(Fe、Cr)ac系の炭化
物(以下、rN13cJと略す、)の分布も転がり疲れ
寿命に影響し、とくに正偏析部に存在する巨大なM3C
が悪影響を及ぼすといわれている。このような巨大なM
3Cをなくすためには、鋳造時に生成した巨大な炭化物
を基地中にいったん固溶させればよく、そのために、高
温で長時間の均熱処理を鋼塊または鋳片に施すことが有
効である。Furthermore, the distribution of M(Fe,Cr)ac-based carbides (hereinafter abbreviated as rN13cJ) contained in the steel also affects the rolling fatigue life, especially the huge M3C present in the positive segregation area.
is said to have a negative effect. Such a huge M
In order to eliminate 3C, it is sufficient to once solidly dissolve the huge carbides generated during casting into the matrix, and for this purpose it is effective to subject the steel ingot or slab to soaking treatment at high temperature for a long time.
(発明が解決しようとする問題点)
上記のように、軸受の転がり疲れ寿命を延長させるため
には、鋼中における非金属介在物の抑制、および巨大な
M3Cの低減が有効であるが、このような軸受の転がり
疲れ寿命をさらに延長させることが要望されていた。(Problems to be Solved by the Invention) As mentioned above, in order to extend the rolling fatigue life of bearings, it is effective to suppress non-metallic inclusions in steel and reduce huge M3C. There has been a desire to further extend the rolling fatigue life of such bearings.
この発明は、このような要望に鑑みてなされたもので、
上述の非金属介在物の抑制、および巨大なM3Cの低減
による以外に、軸受の転がり疲れ寿命を延長させる要因
について種々の検討を加えた結果、初期の目的である軸
受の転がり疲れ寿命をさらに延長させることが可能であ
る軸受鋼を開発した。This invention was made in view of these demands.
In addition to the above-mentioned suppression of non-metallic inclusions and reduction of huge M3C, we conducted various studies on factors that extend the rolling fatigue life of bearings, and as a result, we were able to further extend the rolling fatigue life of bearings, which was our initial objective. We have developed a bearing steel that can
[発明の構成]
(問題点を解決するための手段)
この発明は、炭素含有量が0.8〜1.2重量%である
高炭素クロム系の軸受鋼において、S十P含有量がo、
oto重量%以下であるようにしたことを特徴とするも
ので′ある。[Structure of the Invention] (Means for Solving the Problems) This invention provides a high carbon chromium bearing steel with a carbon content of 0.8 to 1.2% by weight, in which the S and P content is o. ,
% by weight or less.
すなわち、本発明者は、軸受の転がり疲れ寿命を延長さ
せる要因について種々検討を加えた結果、上記の非金属
介在物の抑制、および巨大なM3Cの低減に加えて、S
+P含有量を0.010重量%以下とすることにより、
前記のM3Cの分布をより均一かつ微細化できること、
およびこのことにより転がり疲れ寿命のより一層の改善
をはかりうろことを見い出したのである。That is, as a result of various studies on factors that extend the rolling fatigue life of bearings, the inventors have found that, in addition to suppressing the above-mentioned nonmetallic inclusions and reducing huge M3C,
By setting the +P content to 0.010% by weight or less,
The distribution of M3C can be made more uniform and finer;
They discovered that this would further improve rolling fatigue life.
このような軸受鋼におけるS十P含有量の低減は、溶鋼
凝固時におけるCのミクロ偏析を軽減し、鋳造状態での
炭化物の分布を均一かつ微細化し、その後の均熱処理に
おいて炭化物の基地中への固溶を容易にする。その結果
、その後の圧延−球状化焼なまし一焼入れ・焼もどしと
いう熱履歴を経た後の炭化物の粒筏が小さくなり、軸受
の転がり疲れ寿命が著しく向上する。Such a reduction in the S0P content in bearing steel reduces the micro-segregation of C during solidification of molten steel, makes the distribution of carbides uniform and fine in the cast state, and allows the carbides to enter the matrix in the subsequent soaking process. Facilitates solid solution of As a result, the carbide grain rafts after the subsequent thermal history of rolling, spheroidizing annealing, quenching, and tempering become smaller, and the rolling fatigue life of the bearing is significantly improved.
この発明が適用される軸受鋼としては、例えば、C:0
.8〜1 、21fL量%、S i、: 0 、1〜2
.0重量%、M n : 0 、 2〜2 、
0重量%、(:r:0.5〜2.5重量%、および必
要に応じて、Ni:5重量%以下、Mo:2重量%以下
のうちの1種または2種を含み、残部Feおよび不純物
からなるものがある。As the bearing steel to which this invention is applied, for example, C:0
.. 8-1, 21fL amount%, Si,: 0, 1-2
.. 0% by weight, Mn: 0, 2-2,
0% by weight, (:r: 0.5 to 2.5% by weight, and if necessary, contains one or two of Ni: 5% by weight or less, Mo: 2% by weight or less, and the balance is Fe. and impurities.
このような組成の軸受鋼がとくに好ましいのは、次に示
す理由による。The reason why bearing steel having such a composition is particularly preferable is as follows.
C:0.S〜1.2重量%
Cは軸受の強度、硬さおよび耐摩耗性を向上させ、その
寿命を高めるのに有効な元素であるので、このような効
果を得るために0.8重量%以上とするのが良い。しか
し、C含有量が多くなると鋼中の炭化物も巨大化する傾
向となり、軸受の転がり疲れ寿命が低下するので1.2
i量%以下とするのが良い、なお、この発明による軸受
鋼においてはP+S量を低減しているため焼割れ限界が
向上し、C含有量の上限を高めることができるので、高
強度および高庁耗性の軸受を焼割れなく得ることができ
るようになる。C: 0. S ~ 1.2% by weight C is an effective element for improving the strength, hardness, and wear resistance of bearings and increasing their lifespan, so in order to obtain such effects, 0.8% by weight or more It is better to However, as the C content increases, the carbides in the steel tend to grow larger, reducing the rolling fatigue life of the bearing.
In addition, in the bearing steel according to the present invention, since the P+S content is reduced, the quench cracking limit is improved, and the upper limit of the C content can be increased, so that high strength and high It is now possible to obtain bearings that are prone to wear and tear without cracking.
Si:0.1〜2.0重量%
5iは鋼の溶製時において脱醜剤として作用すると共に
、焼入性を向上して軸受の寿命を延長するのに有効な元
素であるので、このような効果を得るために0.11f
i1%以上とするのが良い。しかし、St含有量が多す
ぎると被削性が低下するのでz、oi−’、、%以下と
するのが良い。Si: 0.1 to 2.0% by weight 5i is an element that acts as a deodorizing agent during steel melting and is effective in improving hardenability and extending the life of bearings. 0.11f to obtain such an effect.
It is preferable to set i1% or more. However, if the St content is too large, the machinability decreases, so it is preferable to keep it below z,oi-'%.
Mn:0.2〜2.0重量%
Mnは、鋼の溶製時において脱酸および脱硫剤として作
用すると共に、焼入性を向上して基地の強靭性を高め、
軸受の寿命を延長するのに有効な元素であるので、この
ような効果を得るために0 、2重量%以上とするのが
良い、しかし、Mn含有量を多くしても寿命の向上はみ
られず、かえって被削性を低下させるので2.0重量%
以下とするのが良い。Mn: 0.2-2.0% by weight Mn acts as a deoxidizing and desulfurizing agent during steel melting, improves hardenability and increases the toughness of the base,
Since it is an effective element for extending the life of bearings, it is best to use it at 0.2% by weight or more to obtain this effect.However, even if the Mn content is increased, the life will not be improved. 2.0% by weight because it does not reduce the machinability of the
It is best to set it to the following.
Cr:0.5〜2.5重量%
Crは炭化物の均一微細化に寄がすると共に焼入性を向
上させ、基地の強靭性を高めて軸受の寿命を延長させる
のに有効な元素であるので、このような効果を得るため
に0.5重量%以上とするのが良い。しかし、Cr含有
量が多くなりすぎると均一微細な炭化物が得にくくなり
、軸受の寿命を向上させることができなくなるので2.
5重量%以下とするのが良い。Cr: 0.5 to 2.5% by weight Cr is an effective element that contributes to the uniform refinement of carbides, improves hardenability, increases the toughness of the matrix, and extends the life of the bearing. Therefore, in order to obtain such an effect, it is preferable to set the content to 0.5% by weight or more. However, if the Cr content increases too much, it becomes difficult to obtain uniform and fine carbides, making it impossible to improve the life of the bearing.
The content is preferably 5% by weight or less.
Ni:5重量%以下、Mo : 2重量%以下のうちの
1種または2種
NiおよびMoは焼入性の向上に有効な元素であり、軸
受の強靭性を増大させるのに有効であるので、軸受の大
きさ等を考慮して必要に応じて添加してもよい。しかし
、多量に含有すると炭化物が微細かつ均一に分散しなく
なり、かえって靭性を低下させるので、添加する場合で
も、Niについては5重量%以下、MOについては2重
量%以下とするのが良い。Ni: 5% by weight or less, Mo: 2% by weight or less.Ni and Mo are elements effective in improving hardenability, and are effective in increasing the toughness of the bearing. , may be added as necessary in consideration of the size of the bearing, etc. However, if it is added in a large amount, the carbides will not be finely and uniformly dispersed, which will actually reduce the toughness, so even when added, the amount of Ni is preferably 5% by weight or less, and the amount of MO is preferably 2% by weight or less.
この発明による軸受鋼は、上記のより好ましい組成の鋼
において、前述したように、S+P含有量を0.010
重量%以下に規制し、溶鋼凝固時における炭素のミクロ
偏析を軽減し、鋳造状態での炭化物の分布を均一かつ微
細化し、その後の均熱処理において炭化物の基地中への
固溶を容易にし、その結果焼入れ、焼もどし後の炭化物
の粒径が小さくなるようにして軸受の転がり疲れ寿命を
著しく向上させたものである。The bearing steel according to the present invention has an S+P content of 0.010 as described above in the steel having the above-mentioned more preferable composition.
% by weight or less, to reduce micro-segregation of carbon during solidification of molten steel, to make the distribution of carbides uniform and fine in the casting state, and to facilitate the solid solution of carbides into the matrix in the subsequent soaking treatment. As a result, the grain size of the carbide after quenching and tempering is reduced, significantly improving the rolling fatigue life of the bearing.
なお、このようなS+P含有量の低減は、原料の精選、
精錬時における脱S、脱Pの強化等によって実現される
。In addition, such reduction of S+P content is achieved by careful selection of raw materials,
This is achieved by strengthening removal of S and P during refining.
そして、この発明による軸受鋼において、これを素材と
する軸受の転がり疲れ寿命の延長は。The bearing steel according to the present invention extends the rolling fatigue life of bearings made of this material.
S+P含有量の低減のほかに、前述したように非金属介
在物の抑制によっても実現されるので、AfL203
.5i02 、MnS、TiN等の量を抑制するため
に、鋼中の不純物においてとくにより望ましくはTi:
0.003重量%以下、0:0.0O10重量%以下、
N:0.006重量%以下であるようにするのが良い。In addition to reducing the S+P content, this is also achieved by suppressing nonmetallic inclusions as described above, so AfL203
.. In order to suppress the amount of 5i02, MnS, TiN, etc., it is particularly preferable that Ti:
0.003% by weight or less, 0:0.0O10% by weight or less,
N: It is preferable that the content is 0.006% by weight or less.
(実施例)
電気炉溶解および取鍋精錬によって第1表に示す成分の
鋼を溶製したのち鋳造し、1300℃×24Hr711
熱による均熱処理を行ったのち分塊圧延し、次いで小型
圧延を行ったのち球状化焼なましを施した。(Example) After melting steel with the components shown in Table 1 by electric furnace melting and ladle refining, it was cast and heated at 1300°C x 24Hr711
After soaking with heat, it was subjected to blooming rolling, followed by small-sized rolling, and then spheroidizing annealing.
次に、前記の球状化焼なまし材から転勤寿命試験用の試
験片形状に加工したのち、850℃加熱保持後油冷の焼
入れ、および160℃加熱保持後空冷の焼もどしを行い
、次いで研磨して転勤寿命試験用の試験片を作成した。Next, after processing the above-mentioned spheroidized annealed material into the shape of a test piece for a rolling life test, it was heated and held at 850°C, then oil-cooled, tempered, heated and held at 160°C, and then air-cooled, and then polished. A test piece for the transfer life test was prepared.
次に、前記の各試験片を用いて、ヘルツ応力が536k
gf/mm’のスラスト弐転勤寿命試験を行って各試験
片の転勤寿命(累積破損確率lO%)を測定すると共に
、M3C粒径分布測定を行った。これらの結果を第2表
に示す。Next, using each of the above test pieces, the Hertzian stress was 536k.
A thrust two transfer life test of gf/mm' was conducted to measure the transfer life (cumulative failure probability lO%) of each test piece, and M3C particle size distribution was also measured. These results are shown in Table 2.
第2表
第2表に示すように、この発明による軸受鋼(No、
1〜3)は比較の軸受鋼(No、 4 、5)に比べ
てM3 Cの平均直径がかなり小さく、転勤寿命に著し
く優れていることが明らかである。Table 2 As shown in Table 2, bearing steel according to the present invention (No.
It is clear that samples 1 to 3) have a considerably smaller average diameter of M3C than the comparative bearing steels (No. 4, 5), and are significantly superior in rolling life.
[発明の効果]
以上説明してきたように、この発明によれば、度素含有
量が0.8〜1.2重量%である高炭素クロム系の軸受
鋼において、S+P含有量が0.010重量%以下であ
るようにしたから、この軸受鋼中におけるM3 C炭化
物の分布をより均一でかつ微細なものとすることが可能
であり、この軸受鋼を素材とした軸受の転がり疲れ寿命
を著しく延長させることが可能であるという非常に優れ
た効果がもたらされる。[Effects of the Invention] As explained above, according to the present invention, in a high carbon chromium bearing steel having a hydrogen content of 0.8 to 1.2% by weight, the S+P content is 0.010%. % by weight or less, it is possible to make the distribution of M3C carbides in this bearing steel more uniform and finer, and the rolling fatigue life of bearings made from this bearing steel can be significantly extended. A very good effect is that it can be extended.
Claims (4)
クロム系の軸受鋼において、S+P含有量が0.010
重量%以下であることを特徴とする転がり疲れ寿命に優
れた高炭素クロム軸受鋼。(1) In high carbon chromium bearing steel with a carbon content of 0.8 to 1.2% by weight, the S+P content is 0.010
High carbon chromium bearing steel with excellent rolling fatigue life characterized by less than % by weight.
%、Si:0.1〜2.0重量%、Mn:0.2〜2.
0重量%、Cr:0.5〜2.5重量%を含み、S+P
含有量が0.010重量%以下で、残部Feおよび不純
物からなることを特徴とする特許請求の範囲第(1)項
記載の転がり疲れ寿命に優れた高炭素クロム軸受鋼。(2) The high carbon chromium bearing steel contains C: 0.8-1.2% by weight, Si: 0.1-2.0% by weight, Mn: 0.2-2.
0% by weight, Cr: 0.5-2.5% by weight, S+P
A high carbon chromium bearing steel with excellent rolling fatigue life according to claim (1), characterized in that the content is 0.010% by weight or less, with the balance consisting of Fe and impurities.
%、Si:0.1〜2.0重量%、Mn:0.2〜2.
0重量%、Cr:0.5〜2.5重量%、およびNi:
5重量%以下、Mo:2重量%以下のうちの1種または
2種を含み、S+P含有量が0.010重量%以下で、
残部Feおよび不純物からなることを特徴とする特許請
求の範囲第(1)項記載の転がり疲れ寿命に優れた高炭
素クロム軸受鋼。(3) The high carbon chromium bearing steel contains C: 0.8-1.2% by weight, Si: 0.1-2.0% by weight, Mn: 0.2-2.
0% by weight, Cr: 0.5-2.5% by weight, and Ni:
Contains one or two of the following: 5% by weight or less, Mo: 2% by weight or less, and the S+P content is 0.010% by weight or less,
A high carbon chromium bearing steel with excellent rolling fatigue life as claimed in claim (1), characterized in that the remainder consists of Fe and impurities.
、0:0.0010重量%以下、N:0.006重量%
以下であることを特徴とする特許請求の範囲第(2)項
または第(3)項記載の転がり疲れ寿命に優れた高炭素
クロム軸受鋼。(4) Among impurities, Ti: 0.003% by weight or less, 0: 0.0010% by weight or less, N: 0.006% by weight
A high carbon chromium bearing steel with excellent rolling fatigue life according to claim (2) or (3), characterized in that:
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP11426585A JPS61272349A (en) | 1985-05-29 | 1985-05-29 | Bearing steel |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP11426585A JPS61272349A (en) | 1985-05-29 | 1985-05-29 | Bearing steel |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS61272349A true JPS61272349A (en) | 1986-12-02 |
Family
ID=14633468
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP11426585A Pending JPS61272349A (en) | 1985-05-29 | 1985-05-29 | Bearing steel |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS61272349A (en) |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6263650A (en) * | 1985-09-13 | 1987-03-20 | Aichi Steel Works Ltd | Bearing steel and its production |
JPH0230733A (en) * | 1988-04-04 | 1990-02-01 | Koyo Seiko Co Ltd | High carbon chromium bearing steel |
JPH03285041A (en) * | 1989-09-19 | 1991-12-16 | Sumitomo Metal Ind Ltd | Steel tube for bearing race suitable for cold form rolling |
JPH04165045A (en) * | 1990-10-25 | 1992-06-10 | Nachi Fujikoshi Corp | Medium-carbon and chromium series bearing steel |
JPH04165046A (en) * | 1990-10-25 | 1992-06-10 | Nachi Fujikoshi Corp | Medium chromium series bearing steel |
US5403545A (en) * | 1990-05-23 | 1995-04-04 | Aichi Steel Works, Ltd. | Bearing steel |
WO2001029277A1 (en) * | 1999-10-21 | 2001-04-26 | Koyo Seiko Co., Ltd. | Steel for large bearing and parts for large bearing |
JP2009084647A (en) * | 2007-09-28 | 2009-04-23 | Kobe Steel Ltd | Steel for bearing having excellent stability of rolling fatigue life |
JP2010047832A (en) * | 2008-07-24 | 2010-03-04 | Kobe Steel Ltd | Steel for bearing having excellent rolling fatigue life |
-
1985
- 1985-05-29 JP JP11426585A patent/JPS61272349A/en active Pending
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6263650A (en) * | 1985-09-13 | 1987-03-20 | Aichi Steel Works Ltd | Bearing steel and its production |
JPH0230733A (en) * | 1988-04-04 | 1990-02-01 | Koyo Seiko Co Ltd | High carbon chromium bearing steel |
JPH03285041A (en) * | 1989-09-19 | 1991-12-16 | Sumitomo Metal Ind Ltd | Steel tube for bearing race suitable for cold form rolling |
US5403545A (en) * | 1990-05-23 | 1995-04-04 | Aichi Steel Works, Ltd. | Bearing steel |
JPH04165045A (en) * | 1990-10-25 | 1992-06-10 | Nachi Fujikoshi Corp | Medium-carbon and chromium series bearing steel |
JPH04165046A (en) * | 1990-10-25 | 1992-06-10 | Nachi Fujikoshi Corp | Medium chromium series bearing steel |
WO2001029277A1 (en) * | 1999-10-21 | 2001-04-26 | Koyo Seiko Co., Ltd. | Steel for large bearing and parts for large bearing |
US6582532B1 (en) | 1999-10-21 | 2003-06-24 | Koyo Seiko Co., Ltd. | Steel for large bearing and parts for large bearing |
KR100497828B1 (en) * | 1999-10-21 | 2005-07-01 | 고요 세이코 가부시키가이샤 | Steel for large bearing and parts for large bearing |
JP2009084647A (en) * | 2007-09-28 | 2009-04-23 | Kobe Steel Ltd | Steel for bearing having excellent stability of rolling fatigue life |
JP2010047832A (en) * | 2008-07-24 | 2010-03-04 | Kobe Steel Ltd | Steel for bearing having excellent rolling fatigue life |
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