JP3241921B2 - Wear-resistant and corrosion-resistant bearing steel with excellent rolling fatigue characteristics - Google Patents
Wear-resistant and corrosion-resistant bearing steel with excellent rolling fatigue characteristicsInfo
- Publication number
- JP3241921B2 JP3241921B2 JP04633994A JP4633994A JP3241921B2 JP 3241921 B2 JP3241921 B2 JP 3241921B2 JP 04633994 A JP04633994 A JP 04633994A JP 4633994 A JP4633994 A JP 4633994A JP 3241921 B2 JP3241921 B2 JP 3241921B2
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- Prior art keywords
- steel
- less
- resistant
- rolling fatigue
- fatigue characteristics
- Prior art date
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Description
【０００１】[0001]
【産業上の利用分野】本発明は、転動寿命特性が優れた
耐摩耗性、耐食性を有するマルテンサイト系ステンレス
軸受鋼に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a martensitic stainless steel bearing steel having excellent rolling life characteristics and excellent wear and corrosion resistance.
【０００２】[0002]
【従来の技術】従来から、比較的高い温度で使用が可能
で、腐食環境に対しても優れた耐食性を有する軸受鋼と
して、ＪＩＳ ＳＵＳ４４０Ｃ鋼、ＢＡＳ ４４０Ｍ鋼
(１．１Ｃ−１４．５Ｃｒ−４Ｍｏ−Ｆｅ），０．７Ｃ
−１２Ｃｒ鋼等が用いられている。これらのマルテンサ
イトステンレス鋼は、耐熱性、耐食性、耐摩耗性の点で
ＪＩＳ Ｇ４８０５に規定されている高炭素クロム軸受
鋼(ＳＵＪ)より優れているが、転動疲労特性が劣る欠点
がある。上記鋼のうち、ＳＵＳ４４０Ｃは製造時に巨大
な共晶炭化物が鋼中に残留し易く、そのため転動疲労特
性が低下する問題があった。この問題を解消する目的
で、ＣとＣrをともに低めて転動疲労特性を改善した鋼
が特開昭５３−１０３９１７号に提案されている。2. Description of the Related Art Conventionally, JIS SUS440C steel and BAS 440M steel have been used as bearing steels which can be used at relatively high temperatures and have excellent corrosion resistance to corrosive environments.
(1.1C-14.5Cr-4Mo-Fe), 0.7C
-12Cr steel or the like is used. These martensitic stainless steels are superior to high carbon chromium bearing steel (SUJ) specified in JIS G4805 in terms of heat resistance, corrosion resistance, and wear resistance, but have a disadvantage that rolling fatigue characteristics are inferior. Among the above-mentioned steels, SUS440C has a problem in that giant eutectic carbides tend to remain in the steel at the time of production, so that rolling fatigue characteristics are reduced. For the purpose of solving this problem, Japanese Patent Application Laid-Open No. 53-103917 proposes a steel in which both C and Cr are reduced to improve the rolling fatigue characteristics.
【０００３】軸受は、機械などの軸の回転を案内し、回
転軸にかかる荷重を支え保持する重要な機械要素であ
り、あらゆる機械器具に使用されている。近年、機器類
においては、高性能化、高精度化の要求が高まる一方で
高速回転、使用温度、腐食雰囲気など、従来に増して使
用環境の厳しさに耐え得る軸受鋼が求められている。A bearing is an important mechanical element that guides the rotation of a shaft of a machine or the like and supports and holds a load applied to the rotating shaft, and is used in all kinds of machine tools. In recent years, in equipment, bearing steel that can withstand more severe operating environments such as high-speed rotation, operating temperatures, and corrosive atmospheres has been demanded, while demands for higher performance and higher accuracy have been increasing.
【０００４】[0004]
【発明が解決しようとする課題】上記の特開昭５３−１
０３９１７号の鋼は、転動寿命の点でＳＵＳ４４０Ｃ鋼
よりも優れているが、耐摩耗性、耐腐食性などの面で、
必ずしも軸受鋼として十分とはいえない問題があった。
これら耐摩耗性や耐腐食性の低下は機器類の性能や精度
を損なうだけでなく、騒音の発生原因にもなり軸受鋼と
して求められる重要な特性の一つである。本発明の目的
は、ＳＵ４４０Ｃ鋼の耐摩耗性、耐食性を損なうことな
く、転動疲労特性にも優れた軸受鋼を提供することであ
る。The above-mentioned JP-A-53-1
No. 03917 steel is superior to SUS440C steel in terms of rolling life, but in terms of wear resistance and corrosion resistance,
There was a problem that it was not always sufficient as bearing steel.
These reductions in wear resistance and corrosion resistance not only impair the performance and accuracy of the equipment, but also cause noise and are one of the important characteristics required for bearing steel. An object of the present invention is to provide a bearing steel having excellent rolling fatigue characteristics without impairing the wear resistance and corrosion resistance of SU440C steel.
【０００５】[0005]
【課題を解決するための手段】転動疲労特性の向上のた
めには、耐摩耗性に有効な炭化物を基地中に微細に分散
させるとともに基地自体を強化し、さらに不安定な破壊
を防止する材料欠陥を少なくすることが重要である。発
明者が高Ｃ高Ｃr鋼を対象に、上述の炭化物の微細化と
基地自体の強化について鋭意検討した結果、Ｎを添加し
た鋼は、焼なまし状態でＮをＦeとＣrの窒化物として形
成させ、これを焼入れすると窒化物が固溶して基地の硬
さを著しく高め、転動疲労特性や耐摩耗性を向上できる
ことを新たに見出した。In order to improve rolling fatigue characteristics, carbide effective for wear resistance is finely dispersed in the matrix, the matrix itself is strengthened, and unstable fracture is prevented. It is important to reduce material defects. As a result of the inventor's intense study on the above-mentioned refinement of carbides and strengthening of the matrix itself for high-C high-Cr steels, the steel with N added turns N into Fe and Cr nitrides in the annealed state. It is newly found that when formed and quenched, the nitride forms a solid solution to significantly increase the hardness of the matrix and improve the rolling fatigue characteristics and wear resistance.
【０００６】すなわち本発明は、重量％でＣ 0.5〜1.3
%、Ｓi 1.5%以下、Ｍn 2.0%以下、Ｃr 11〜20%、Ｎ 0.0
6〜0.20%、残部Ｆeおよび不可避的不純物からなり、焼
戻し後の硬さが59HRC以上であることを特徴とする転動
疲労特性に優れた耐摩耐食軸受鋼である。本発明鋼は上
記をベースとして、さらに耐摩耗性が必要な場合および
結晶粒の微細化が必要な場合には、Ｍo 5%以下、Ｗ 3%
以下、Ｖ 2%以下、Ｎb 1%以下から選ばれる一種または
二種以上の元素を組み合わせて添加することができる。
また本発明鋼は、重量％でＣ 0.5〜1.3%、Ｓi 1.5%以
下、Ｍn 2.0%以下、Ｃr 11〜20%、Ｎ 0.06〜0.20%、残
部Ｆeおよび不可避的不純物からなり、焼なまし後の組
織中にＦeとＣrの微細な窒化物が形成されていることを
特徴とする転動疲労特性に優れた耐摩耐食軸受鋼であ
り、Ｍo，Ｗ，Ｖ，Ｎbを上述の範囲内で含むことができ
る。That is, the present invention relates to a method for preparing C 0.5-1.3% by weight.
%, Si 1.5% or less, Mn 2.0% or less, Cr 11-20%, N 0.0
A wear-resistant and corrosion-resistant bearing steel comprising 6 to 0.20%, with the balance being Fe and inevitable impurities, and having a hardness after tempering of 59 HRC or more, and having excellent rolling fatigue characteristics. The steel of the present invention is based on the above, when the wear resistance is further required and when the crystal grains are required to be refined, Mo 5% or less, W 3%
Hereinafter, one or more elements selected from V 2% or less and Nb 1% or less can be added in combination.
The steel of the present invention is composed of 0.5 to 1.3% by weight of C, 1.5% or less of Si, 2.0% or less of Mn, 11 to 20% of Cr, 0.06 to 0.20% of N, and the balance of Fe and inevitable impurities. This is a wear and corrosion resistant bearing steel excellent in rolling fatigue characteristics, characterized in that fine nitrides of Fe and Cr are formed in the structure of Mo, W, V, and Nb within the above-mentioned range. be able to.
【０００７】本発明の最大の特徴は、焼なまし状態にお
いてＦeとＣrの微細な窒化物を形成せしめ、軸受に製造
後の熱処理で容易に固溶するような状態を準備すること
である。ＳＵＳ４４０Ｃなどの従来の軸受鋼は、その硬
さや耐摩耗性の付与を主にＣrの炭化物に依存するため
高Ｃ高Ｃr組成となり、製造時に巨大な共晶炭化物が鋼
中に残存して転動疲労寿命が低下することがあったので
ある。本発明では、焼なまし時のＦeとＣrの微細な多数
の窒化物が焼入時に基地に固溶し、基地の強化が行なえ
るので、軸受の転動疲労特性と耐摩耗性を従来の鋼と比
較して著しく高めることができる。したがって、本発明
の適正な組成の組合せは上記の作用を考慮して決定する
ことができる。The most significant feature of the present invention is to form a fine nitride of Fe and Cr in the annealed state and to prepare a state in which the bearing easily dissolves by heat treatment after manufacturing. Conventional bearing steels such as SUS440C have a high C and high Cr composition because their hardness and wear resistance mainly depend on the carbides of Cr. Giant eutectic carbides remain in the steel during production and cause rolling. The fatigue life was sometimes reduced. In the present invention, a large number of fine nitrides of Fe and Cr at the time of annealing dissolve in the matrix at the time of quenching, and the matrix can be strengthened. It can be significantly increased compared to steel. Therefore, an appropriate composition combination according to the present invention can be determined in consideration of the above-mentioned effects.
【０００８】[0008]
【作用】以下に本発明鋼の成分限定理由について述べ
る。Ｃはマルテンサイト系ステンレス鋼の硬さを得る上
で最も重要な元素の一つである。また、Ｃrの他、Ｍo，
Ｗ，Ｖ，Ｎbと炭化物をつくり、耐摩耗性の向上に寄与
する。本発明の鋼の高強度を得るためには、最低0.5%以
上必要であるが、1.3%を越えると共晶炭化物が粗大化し
て転動疲労特性が低下するため、Ｃの範囲を0.5〜1.3%
に限定する。望ましいＣの範囲は1.0〜1.2%である。Ｓi
は、鋼の脱酸元素として必要な添加元素である。しか
し、過度のＳiの添加は、靭性の低下が著しくなるた
め、1.5%以下とする。Ｓiの望ましい添加量は1.2%以下
である。The reasons for limiting the composition of the steel of the present invention will be described below. C is one of the most important elements for obtaining the hardness of martensitic stainless steel. In addition to Cr, Mo,
It forms carbides with W, V, Nb and contributes to improvement of wear resistance. In order to obtain the high strength of the steel of the present invention, at least 0.5% or more is necessary.However, if it exceeds 1.3%, the eutectic carbide becomes coarse and the rolling fatigue characteristics are reduced. %
Limited to. A desirable range of C is 1.0 to 1.2%. Si
Is an additional element required as a deoxidizing element of steel. However, excessive addition of Si significantly reduces toughness. Desirable addition amount of Si is 1.2% or less.
【０００９】ＭnはＳiと同じく脱酸剤として用いられ、
またオーステナイト安定化元素である窒素と同時に用い
るため、焼入れ時に残留オーステナイトが過多となるの
で、2.0%以下とする。望ましいＭnの含有量は1.5%以下
である。Ｃrは、本発明鋼の耐食性を向上させるため必
須の元素であるとともに、硬質のＣr系炭化物を作り、
耐摩耗性を向上させる効果がある。本発明鋼に耐食性、
耐摩耗性を共に向上させるためには、最低11%の含有量
が必要である。しかし、Ｃrが多過ぎると共晶炭化物が
粗大化し、転動疲労特性を低下させる原因となるため、
その上限を2.0%とする。Ｃrの望ましい範囲は15〜18%で
ある。Mn is used as a deoxidizing agent like Si,
Further, since it is used together with nitrogen, which is an austenite stabilizing element, the amount of retained austenite becomes excessive during quenching. Desirable Mn content is 1.5% or less. Cr is an essential element for improving the corrosion resistance of the steel of the present invention, and also forms a hard Cr-based carbide,
This has the effect of improving wear resistance. Corrosion resistance,
In order to improve both wear resistance, a content of at least 11% is necessary. However, if the Cr content is too large, the eutectic carbides become coarse, which causes the rolling contact fatigue characteristics to deteriorate.
The upper limit is 2.0%. The desirable range of Cr is 15-18%.
【００１０】Ｎは、本発明合金において最も重要な元素
である。すなわち、Ｎを添加することにより、焼なまし
状態でＮをＦeとＣrの微細な窒化物、例えば(Ｃr・Ｆe)2
Ｎとして形成させた後、焼入れを行なうとこれらの窒化
物が固溶して基地を強化する効果がある。本発明のこれ
らの特徴は、後に説明する実施例４などの組織、Ｘ線回
折結果から明らかにわかる。また、Ｎの添加は、基地中
に残留する一次炭化物の粗大成長を抑制する効果もあ
り、軸受として重要な転動疲労特性および耐摩耗性の向
上に特に有効である。Ｎが0.06%以下では、その効果が
得られず、また0.2%を越えて含有させると残留オーステ
ナイト相をマルテンサイト相に変態させることができな
くなり、硬さが低下するためその上限を0.2%とする。Ｎ
の望ましい範囲は0.06〜0.17%である。[0010] N is the most important element in the alloy of the present invention. That is, by adding N, N can be converted into fine nitrides of Fe and Cr in an annealed state, for example, (Cr.Fe) 2
When quenching is performed after forming N, these nitrides have the effect of strengthening the matrix by forming a solid solution. These features of the present invention can be clearly understood from the structure and the X-ray diffraction result of Example 4 described later. Further, the addition of N also has the effect of suppressing the coarse growth of primary carbides remaining in the matrix, and is particularly effective in improving rolling fatigue characteristics and wear resistance, which are important as bearings. If N is 0.06% or less, the effect cannot be obtained, and if the content exceeds 0.2%, the retained austenite phase cannot be transformed into a martensite phase, and the hardness is reduced, so the upper limit is 0.2%. I do. N
Is a preferable range of 0.06 to 0.17%.
【００１１】Ｍo，Ｗ，Ｖ，Ｎbは、炭化物を形成し、耐
摩耗性を高める効果を有するとともに、一部は基地中に
固溶して焼戻し軟化抵抗を高める効果があり、必要に応
じて一種または二種以上添加することができる。しか
し、多量に含有すると、熱間加工性を害するため、Ｍ
o，Ｗ，Ｖ，Ｎbの上限をそれぞれ5%,3%,2%,1%とする。
上記の元素のうち、Ｍoは耐食性の向上にも寄与し、ま
たＶとＮbは、本発明のＮ含有による結晶粒の微細化を
助長させ、転動疲労性を高める効果があり、軸受として
使用される条件によって適宜選択するのが良い。Mo, W, V, and Nb form carbides and have an effect of increasing abrasion resistance, and some have an effect of forming a solid solution in a matrix to increase tempering softening resistance. One or two or more can be added. However, if contained in a large amount, hot workability is impaired.
The upper limits of o, W, V, and Nb are set to 5%, 3%, 2%, and 1%, respectively.
Of the above elements, Mo also contributes to the improvement of corrosion resistance, and V and Nb have the effect of promoting the refinement of crystal grains due to the N content of the present invention and increasing the rolling fatigue resistance, and are used as bearings. It is better to select appropriately according to the conditions to be performed.
【００１２】本発明鋼は、高Ｃ高Ｃr鋼にＮを0.06〜0.2
%含有するため、焼なまし状態でＮをＦeとＣrの窒化物
として形成させ、これを焼入れすることにより基地中に
固溶させると基地の硬さを一段と高めることができる。
なお、焼入れ時に残留オーステナイトが多く残存する。
硬質の軸受にするためには、焼入れ時に残存する残留オ
ーステナイト相をマルテンサイト相にする必要がある。
そのため、焼入れ後にサブゼロ処理を行ない、続いて焼
戻し行なうのが良い。このようにして得られた軸受鋼
は、焼戻し後の硬さが59HRC以上とすることができ、特
に精密機器用軸受や腐食性環境や高温で使用されるＬＮ
Ｇポンプ、ミニモーターシャフト、キャプスタン軸など
の転動疲労および耐摩耗性が要求される部材に好適であ
る。The steel of the present invention contains N in a high C high Cr steel in an amount of 0.06 to 0.2.
Therefore, if N is formed as a nitride of Fe and Cr in an annealed state and then quenched to form a solid solution in the matrix, the hardness of the matrix can be further increased.
Note that a large amount of retained austenite remains during quenching.
In order to form a hard bearing, it is necessary to convert the residual austenite phase remaining during quenching into a martensite phase.
Therefore, it is preferable to perform the sub-zero treatment after the quenching and then perform the tempering. The bearing steel thus obtained can have a hardness of at least 59 HRC after tempering, and is particularly suitable for bearings for precision equipment and LN used in corrosive environments and high temperatures.
It is suitable for members requiring rolling fatigue and wear resistance, such as G pumps, mini motor shafts, capstan shafts, and the like.
【００１３】[0013]
【実施例】以下に実施例を示し、本発明を詳細に説明す
る。 （実施例１）表１は、実施例に使用した鋼の化学成分を
示す。各鋼は真空溶解炉で吹製し、窒素添加鋼について
は、真空炉に窒素を0.75気圧雰囲気にして窒素を添加、
吹製した。表１に示す鋼のうち、Ｎo.1〜16は本発明鋼
であり、Ｎo.20はＳＵＳ４４０Ｃ、Ｎo.21はＢＡＳ４４
０Ｍ、Ｎo.22は特開昭53-103917号に開示された鋼であ
る。The present invention will be described in detail below with reference to examples. (Example 1) Table 1 shows the chemical components of the steel used in the examples. Each steel is blown in a vacuum melting furnace, and for nitrogen-added steel, nitrogen is added to the vacuum furnace in a 0.75 atm atmosphere and nitrogen is added.
I shot it. Among the steels shown in Table 1, Nos. 1 to 16 are steels of the present invention, No. 20 is SUS440C, and No. 21 is BAS44.
OM, No. 22 is a steel disclosed in JP-A-53-103917.
【００１４】[0014]
【表１】 [Table 1]
【００１５】吹製した鋼塊は、疵取、分塊鍛造後、２０
角に仕上げ鍛造した。次いで、焼なまし処理を行なった
後、以下に示す試験に供した。なお、Ｎを含有する本発
明鋼は、焼なまし状態でのＸ線解析によれば、窒素が主
に微細な(Ｃr・Ｆe)2Ｎの形で存在していることが確認さ
れた。このことは実施例４でもデータを示して解説す
る。図１は、本発明鋼であるＮo.1および従来鋼である
Ｎo.20について、1030℃で油焼入れした後、-75℃で2時
間のサブゼロ処理を行ない、次いで100〜400℃の各温度
で焼戻しを行なった試料の硬さ曲線を示したものであ
る。図１からわかるように、Ｎを0.120%含有する本発明
鋼は、Ｎを添加しない従来鋼よりサブゼロ処理後の硬さ
が高く、焼戻し軟化抵抗も高いことを示している。硬さ
を高めるＮの機構は十分解明できなかったが、焼なまし
状態で存在していた（Ｃr・Ｆe)2Ｎの析出物が焼入れ後
には確認されなかったことから推察すると、Ｎは主に固
溶した状態で基地の強化に関与しているものと考えられ
る。The blown steel ingot is subjected to flaw removal and slab forging, and
Finished and forged into corners. Next, after performing an annealing treatment, it was subjected to the following test. According to the X-ray analysis in the annealed state of the steel of the present invention containing N, it was confirmed that nitrogen was mainly present in the form of fine (Cr.Fe) 2 N. This will be described in Example 4 with data. FIG. 1 shows that the steel No. 1 of the present invention and the conventional steel No. 20 were subjected to oil quenching at 1030 ° C., then subjected to a sub-zero treatment at −75 ° C. for 2 hours, and then to a temperature of 100 to 400 ° C. 2 shows a hardness curve of a sample that has been tempered. As can be seen from FIG. 1, the steel of the present invention containing 0.120% of N has a higher hardness after sub-zero treatment and a higher temper softening resistance than the conventional steel to which N is not added. Although the mechanism of N to increase the hardness could not be sufficiently elucidated, it was inferred from the fact that (Cr.Fe) 2 N precipitates existing in the annealed state were not confirmed after quenching, and N It is thought that it is involved in strengthening the base in a state of solid solution.
【００１６】（実施例２）表１に示す各鋼について、10
30℃で油焼入れした後、-75℃×2時間のサブゼロ処理を
行ない、次いで160℃×2時間の焼戻しを行なった後、硬
さ試験、シャルピー衝撃試験、転動疲労試験、孔食電位
の測定を行ない、その結果を表２に併記する。なお、シ
ャルピー衝撃試験片は10RのＣノッチで行ない、転動疲
労試験は、12mmφ×22mmLの試験片を作表し、これを鋼
球の間に挾み、ヘルツ最大接触応力 5880MPaで4400rpm
にて試験した。寿命は50%破損までの回転数で表示し
た。さらに、孔食電位の測定には、3.5%のＮaＣl水溶液
を30℃とし、100mAの電流を流れた時の電圧値(mV)を測
定した。本発明鋼は、同じレベルのＣ含有量の従来鋼と
比較すると同一熱処理したにもかかわらず、明らかに高
い59HRC以上の硬さを示している。さらに本発明鋼は、
衝撃値および転動疲労特性がＳＵＳ４４０Ｃより優れて
いる他、孔食電位もＳＵＳ４４０Ｃと同等であることが
わかる。Example 2 For each steel shown in Table 1, 10
After oil quenching at 30 ° C, sub-zero treatment at -75 ° C x 2 hours is performed, then tempering at 160 ° C x 2 hours, hardness test, Charpy impact test, rolling fatigue test, pitting potential The measurement was performed, and the results are shown in Table 2. The Charpy impact test specimen was performed with a C notch of 10R, and the rolling fatigue test was performed by preparing a test specimen of 12 mmφ × 22 mmL, sandwiched between steel balls, and having a maximum contact stress of 5880 MPa at 4400 rpm at Hertz maximum contact stress.
Was tested. The life was indicated by the number of revolutions up to 50% failure. Further, in measuring the pitting potential, a 3.5% NaCl aqueous solution was set at 30 ° C., and a voltage value (mV) when a current of 100 mA was passed was measured. The steel according to the invention shows a distinctly higher hardness above 59 HRC, despite the same heat treatment when compared to conventional steels of the same level of C content. Further, the steel of the present invention
It can be seen that the impact value and the rolling fatigue characteristics are superior to SUS440C, and the pitting potential is equivalent to SUS440C.
【００１７】[0017]
【表２】 [Table 2]
【００１８】（実施例３）表１に示す本発明鋼Ｎo.3,6,
8および従来鋼Ｎo.20,21,22の鋼について、1030℃油焼
入れをした後、-75℃×2時間のサブゼロ処理を行ない、
次いで160℃×2時間の焼戻しを行なったのち、大越式摩
耗試験を行なった。その結果を表３に示す。 大越式摩
耗試験の条件は、相手材はＪＩＳ ＳＣＭ４１５焼なま
し材を使用し、乾式にて摩擦スピード 0.78m/s、摩擦距
離 400m、最終荷重 6.8kgで行ない、試験片の摩耗体積
から比摩耗量を求めた。摩耗試験の結果、本発明鋼は従
来鋼に比較して耐摩耗性が優れていることがわかる。Example 3 Inventive steel Nos. 3, 6, and
8 and conventional steel Nos. 20, 21, and 22 were subjected to oil quenching at 1030 ° C and then subjected to sub-zero treatment at -75 ° C for 2 hours.
Then, after tempering at 160 ° C. × 2 hours, an Ogoshi abrasion test was performed. Table 3 shows the results. The conditions of the Ogoshi type abrasion test are as follows: using a JIS SCM415 annealed material as the mating material, dry friction speed is 0.78m / s, friction distance is 400m, final load is 6.8kg. The amount was determined. As a result of the abrasion test, it is understood that the steel of the present invention has better wear resistance than the conventional steel.
【００１９】（実施例４）表１に示す鋼のうち、本発明
鋼Ｎo.6および従来鋼Ｎo.20について、860℃×4時間・徐
冷の焼なまし処理を行なった後、抽出レプリカ法による
電子顕微鏡組織観察した結果を図２に示す。また、同じ
試料について行なったＸ線回折チャートと解析結果を図
３に示す。さらに上記試料を焼なまし後、実施例２と同
じ条件で焼入れ、サブゼロおよび焼戻しを実施した後
に、同様の電子顕微鏡組織観察し、その結果を図４に示
す。(Example 4) Of the steels shown in Table 1, the steel No. 6 of the present invention and the conventional steel No. 20 were subjected to annealing at 860 ° C. for 4 hours and gradually cooled, followed by extraction replica. FIG. 2 shows the results of electron microscopic structure observation by the method. FIG. 3 shows an X-ray diffraction chart and analysis result of the same sample. Further, after annealing the sample, quenching was performed under the same conditions as in Example 2, subzero and tempering were performed, and the same microscopic structure was observed. The results are shown in FIG.
【００２０】図２の（ａ）に示す本発明鋼Ｎo.6は、微
細な析出物が多く分散しており、これをＸ線回折チャー
トと解析結果を示す図３によれば(Ｃr・Ｆe)2Ｎであるこ
とがわかる。一方、図２の（ｂ）に示す従来鋼Ｎo.20に
は、微細な析出物が認められず、Ｘ線回折した結果も
(Ｃr・Ｆe)2Ｎは検出できなかった。また、図４の本発明
鋼Ｎo.6の焼戻し組織には、焼なまし時の微細な(Ｃr・Ｆ
e)2Ｎが認められない。このようにＮを含有する本発明
鋼は、焼なまし後の組織中にＦeとＣrの窒化物が形成さ
れることが特徴である。The steel No. 6 of the present invention shown in FIG. 2 (a) contains a large amount of fine precipitates dispersed therein. According to the X-ray diffraction chart and the analysis result, FIG. ) it can be seen that a 2 N. On the other hand, in the conventional steel No. 20 shown in FIG. 2 (b), no fine precipitate was observed, and the result of X-ray diffraction
(Cr.Fe) 2 N could not be detected. Further, the tempered structure of the steel No. 6 of the present invention shown in FIG.
e) 2 N is not observed. As described above, the steel of the present invention containing N is characterized in that Fe and Cr nitrides are formed in the structure after annealing.
【００２１】[0021]
【表３】 [Table 3]
【００２２】[0022]
【発明の効果】本発明材料は、高Ｃ高Ｃr組成にＮを添
加し、焼なまし状態の組織中にＦeとＣrの微細な窒化物
を形成させ、軸受に成形後の熱処理で容易に固溶するよ
うな状態を準備することで、焼戻し後の強度を一段と向
上することが可能となった。その結果、優れた転動疲労
特性を示し、耐摩耗性と耐食性が従来鋼であるＳＵＳ４
４０Ｃ並みの性質を兼備している軸受鋼として有効であ
る。According to the material of the present invention, N is added to the composition of high C and high Cr to form fine nitrides of Fe and Cr in the structure in the annealed state. By preparing a state of solid solution, the strength after tempering can be further improved. As a result, it shows excellent rolling fatigue characteristics and has abrasion resistance and corrosion resistance of SUS4 which is a conventional steel.
It is effective as a bearing steel having properties similar to 40C.
【図面の簡単な説明】[Brief description of the drawings]
【図１】実施例鋼Ｎo.1およびＮo.20を1030℃で油焼入
れした後、-75℃でサブゼロ処理した材料の焼戻し硬さ
曲線である。FIG. 1 is a temper hardness curve of a material obtained by subjecting Example Steels No. 1 and No. 20 to oil quenching at 1030 ° C. and then performing sub-zero treatment at −75 ° C.
【図２】Ｎo.6およびＮo.20の焼なまし処理後の電子顕
微鏡金属組織写真である。FIG. 2 is an electron microscopic metallographic photograph of No. 6 and No. 20 after annealing.
【図３】Ｎo.6およびＮo.20の焼なまし処理後のＸ線回
折チャートと解析結果を示す図である。FIG. 3 is a diagram showing an X-ray diffraction chart and an analysis result of No. 6 and No. 20 after annealing.
【図４】Ｎo.6およびＮo.20の焼戻し後の電子顕微鏡金
属組織写真である。FIG. 4 is an electron micrograph of a microstructure of No. 6 and No. 20 after tempering.
Claims (4)
Ｍn 2.0%以下、Ｃr11〜20%、Ｎ 0.06〜0.20%、残部Ｆe
および不可避的不純物からなり、焼戻し後の硬さが59HR
C以上であることを特徴とする転動疲労特性に優れた耐
摩耐食軸受鋼。C. 0.5 to 1.3% by weight of C, 1.5% or less of Si,
Mn 2.0% or less, Cr 11-20%, N 0.06-0.20%, balance Fe
And hardness of 59HR after tempering
Abrasion and corrosion resistant bearing steel with excellent rolling fatigue characteristics characterized by being at least C.
Ｍn 2.0%以下、Ｃr 11〜20%、Ｎ 0.06〜0.20%を含有
し、さらにＭo 5%以下、Ｗ 3%以下、Ｖ 2%以下、Ｎb 1%
以下から選ばれる一種または二種以上の元素を含み、残
部Ｆeおよび不可避的不純物からなり、焼戻し後の硬さ
が59HRC以上であることを特徴とする転動疲労特性に優
れた耐摩耐食軸受鋼。2. 0.5% to 1.3% by weight of C, 1.5% or less of Si,
Mn 2.0% or less, Cr 11-20%, N 0.06-0.20%, Mo 5% or less, W 3% or less, V 2% or less, Nb 1%
A wear-resistant and corrosion-resistant bearing steel comprising one or more elements selected from the following, the balance being Fe and inevitable impurities, and having a hardness after tempering of 59 HRC or more, and having excellent rolling fatigue characteristics.
Ｍn 2.0%以下、Ｃr11〜20%、Ｎ 0.06〜0.20%、残部Ｆe
および不可避的不純物からなり、焼なまし後の組織中に
ＦeとＣrの微細な窒化物が形成されていることを特徴と
する転動疲労特性に優れた耐摩耐食軸受鋼。(3) C-0.5-1.3% by weight, Si-1.5% or less,
Mn 2.0% or less, Cr 11-20%, N 0.06-0.20%, balance Fe
A wear-resistant and corrosion-resistant bearing steel having excellent rolling fatigue characteristics, characterized in that fine nitrides of Fe and Cr are formed in the structure after annealing, comprising inevitable impurities.
Ｍn 2.0%以下、Ｃr11〜20%、Ｎ 0.06〜0.20%を含有し、
さらにＭo 5%以下、Ｗ 3%以下、Ｖ 2%以下、Ｎb 1%以下
から選ばれる一種または二種以上の元素を含み、残部Ｆ
eおよび不可避的不純物からなり、焼なまし後の組織中
にＦeとＣrの微細な窒化物が形成されていることを特徴
とする転動疲労特性に優れた耐摩耐食軸受鋼。4. The method according to claim 1, wherein the content of C is 0.5 to 1.3% by weight, the content of Si is 1.5% or less,
Mn 2.0% or less, Cr 11-20%, N 0.06-0.20%,
Further, it contains one or more elements selected from Mo 5% or less, W 3% or less, V 2% or less, Nb 1% or less, and the balance F
A wear-resistant and corrosion-resistant bearing steel having excellent rolling fatigue characteristics, comprising e and unavoidable impurities, wherein fine nitrides of Fe and Cr are formed in the structure after annealing.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP04633994A JP3241921B2 (en) | 1994-02-21 | 1994-02-21 | Wear-resistant and corrosion-resistant bearing steel with excellent rolling fatigue characteristics |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP04633994A JP3241921B2 (en) | 1994-02-21 | 1994-02-21 | Wear-resistant and corrosion-resistant bearing steel with excellent rolling fatigue characteristics |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07233442A JPH07233442A (en) | 1995-09-05 |
| JP3241921B2 true JP3241921B2 (en) | 2001-12-25 |
Family
ID=12744388
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP04633994A Expired - Fee Related JP3241921B2 (en) | 1994-02-21 | 1994-02-21 | Wear-resistant and corrosion-resistant bearing steel with excellent rolling fatigue characteristics |
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| DE19924515A1 (en) * | 1999-05-28 | 2000-11-30 | Edelstahl Witten Krefeld Gmbh | Spray-compacted steel, process for its production and composite material |
| JP4644059B2 (en) * | 2005-07-08 | 2011-03-02 | 東洋刃物株式会社 | Application head |
| JP5488973B2 (en) * | 2009-07-03 | 2014-05-14 | 日立金属株式会社 | High hardness steel with excellent softening resistance |
| KR101495999B1 (en) * | 2013-05-03 | 2015-02-25 | 주식회사 포스코 | Heat treatment method of high carbon martensitic stainless steels and high carbon martensite stainless steels manufactured therefrom |
| CN111607766A (en) * | 2019-11-13 | 2020-09-01 | 哈尔滨理工大学 | Method for improving high-temperature frictional wear resistance of M50 steel |
| CN112322989A (en) * | 2020-11-23 | 2021-02-05 | 浙江宝武钢铁有限公司 | High-temperature-resistant wear-resistant bearing steel |
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1994
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| Publication number | Publication date |
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| JPH07233442A (en) | 1995-09-05 |
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