JPH06256898A - Carbo-nitriding steel - Google Patents

Carbo-nitriding steel

Info

Publication number
JPH06256898A
JPH06256898A JP6928193A JP6928193A JPH06256898A JP H06256898 A JPH06256898 A JP H06256898A JP 6928193 A JP6928193 A JP 6928193A JP 6928193 A JP6928193 A JP 6928193A JP H06256898 A JPH06256898 A JP H06256898A
Authority
JP
Japan
Prior art keywords
carbonitriding
weight
steel
carbo
fatigue
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
JP6928193A
Other languages
Japanese (ja)
Inventor
Toshimitsu Kimura
利光 木村
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Daido Steel Co Ltd
Original Assignee
Daido Steel Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Daido Steel Co Ltd filed Critical Daido Steel Co Ltd
Priority to JP6928193A priority Critical patent/JPH06256898A/en
Publication of JPH06256898A publication Critical patent/JPH06256898A/en
Withdrawn legal-status Critical Current

Links

Abstract

PURPOSE:To produce steel showing excellent bending, fatigue and face fatigue properties by carbo-nitriding treatment. CONSTITUTION:The compsn. of this steel is formed of, by weight, 0.15 to 0.40% C, >=0.15% Sm, <=0.40% Mn, 0.5 to 2.0% Cr, 0.03 to 1.0% Al and 0.005 to 0.030% N, and the balance Fe. The hardness of the carbo-nitriding steel can be increased by suitable amounts of Cr and Al in particular.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は歯車、軸受、ピン、タイ
ミングベルト等の構造部品の材料として適する浸炭窒化
用鋼に関するものである。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to carbonitriding steel suitable as a material for structural parts such as gears, bearings, pins and timing belts.

【0002】[0002]

【従来の技術】この種の構造部品の材料としては、浸炭
材よりも高い曲げ、面疲れ強さを要求され、これを満足
せしめるためには浸炭窒化材が有効とされている。従来
は上記構造部品の材料としてJIS肌焼鋼や軟窒化鋼が
使用されている。
2. Description of the Related Art Bending and surface fatigue strength higher than those of carburized materials are required as materials for this kind of structural parts, and carbonitrided materials are considered to be effective for satisfying these requirements. Conventionally, JIS case-hardening steel and soft nitriding steel have been used as materials for the structural parts.

【0003】[0003]

【発明が解決しようとする課題】しかしながら上記従来
のJIS肌焼鋼や軟窒化鋼は浸炭窒化に適した鋼とは言
えず充分な硬化特性が得られないと言う問題点があっ
た。
However, the conventional JIS case-hardening steel and nitrocarburized steel described above are not steels suitable for carbonitriding, and there is a problem that sufficient hardening characteristics cannot be obtained.

【0004】[0004]

【課題を解決するための手段】本発明は浸炭窒化に適し
た鋼を提供することを目的とし、該鋼はC0.15〜
0.40重量%,Si 0.15重量%以下,Mn 0.4
0重量%以下,Cr 0.5〜2.0重量%,Al 0.0
3〜1.0重量%,N0.005〜0.030重量%残
余はFe の組成を有するものである。
The object of the present invention is to provide a steel suitable for carbonitriding, which steel has a C of 0.15.
0.40% by weight, Si 0.15% by weight or less, Mn 0.4
0% by weight or less, Cr 0.5 to 2.0% by weight, Al 0.0
The balance of 3 to 1.0 wt% and N of 0.005 to 0.030 wt% has a composition of Fe.

【0005】[0005]

【作用】本発明においては特にCr ,およびAl に注目
した。Cr は浸炭性を上げて表面炭素濃度を確保するた
めに有効であり、更に浸炭層の靱性を向上させまた浸炭
窒化中に微細な窒化物を形成して浸炭窒化層の硬さを高
める。しかし一方ではCr の過剰の添加は浸炭窒化中、
粒界酸化の生成を助長することがあり、また粒界に炭化
物を析出させることがある。したがってCr の含有量は
0.5〜2.0重量%(以下単に%とする)の範囲とす
べきである。Al は浸炭窒化中、微細窒化物を形成して
浸炭窒化層の硬さを高める。しかし一方では浸炭性を阻
害しかつフェライトを形成し易く、焼入れ後の心部組織
がマルテンサイトとフェライトの二相になり易く、この
ために心部靱性の低下をもたらすが、この特性は熱処理
歪の軽減には有効である。更にAl の過剰の添加は浸炭
窒化中、粒界酸化の生成を助長する。したがってAl の
含有量は0.03〜1.0%とすべきである。Cは0.
15%以上の含有量で心部の強度を維持するが、0.4
0%を越えると心部靱性の低下を招く。Si は浸炭中に
粒界酸化の生成を助長しかつ浸炭窒化性を阻害するので
0.15%以下の含有量に制限すべきである。Mn もS
i 同様な作用を有するから0.04%以下に制限すべき
である。Nは0.005%以上の含有量で窒化物を形成
させ結晶粒成長を防止するが、0.030%を越える含
有量でこのような効果は飽和する。
In the present invention, particular attention was paid to Cr and Al. Cr is effective in increasing the carburizing property and ensuring the surface carbon concentration, and further improves the toughness of the carburized layer and forms fine nitrides during carbonitriding to increase the hardness of the carbonitrided layer. However, on the other hand, the excessive addition of Cr is caused by carbonitriding,
It may promote the formation of grain boundary oxidation and may precipitate carbides at grain boundaries. Therefore, the Cr content should be in the range of 0.5 to 2.0% by weight (hereinafter simply referred to as "%"). Al forms fine nitrides during carbonitriding to increase the hardness of the carbonitrided layer. However, on the other hand, it hinders carburization and facilitates the formation of ferrite, and the core structure after quenching is likely to be a two-phase structure of martensite and ferrite, which leads to a decrease in core toughness. Is effective in reducing Furthermore, the excessive addition of Al promotes the formation of grain boundary oxidation during carbonitriding. Therefore, the Al content should be 0.03 to 1.0%. C is 0.
The content of 15% or more maintains core strength, but 0.4
If it exceeds 0%, the toughness of the core is deteriorated. Since Si promotes the formation of intergranular oxidation during carburization and inhibits carbonitriding, Si should be limited to a content of 0.15% or less. Mn is also S
Since it has a similar effect, it should be limited to 0.04% or less. When N is contained in an amount of 0.005% or more, it forms a nitride to prevent crystal grain growth, but when the amount of N exceeds 0.030%, such an effect is saturated.

【0006】上記本発明の基本組成に加えて、本発明で
は更にMo ,Ni ,V,Nb の一種または二種以上が添
加される。Mo およびNi は鋼の靱性を向上させるが、
過剰の添加では上記効果は飽和し単にコストアップを招
くのみである。したがってMo は0.05〜0.5%,
Ni は0.1〜1.0%の範囲に限定する。VおよびN
b は浸炭窒化中、微細炭窒化物を形成せしめ結晶粒の粗
大化を防止して靱性を維持するが、過剰の添加では上記
結果は飽和するからVは0.05〜0.5%,Nb は
0.01〜0.1%の範囲に限定する。
In addition to the basic composition of the present invention described above, in the present invention, one or more of Mo, Ni, V and Nb are further added. Mo and Ni improve the toughness of steel,
If added excessively, the above effect is saturated and the cost is simply increased. Therefore, Mo is 0.05-0.5%,
Ni is limited to the range of 0.1 to 1.0%. V and N
b causes fine carbonitrides to be formed during carbonitriding to prevent coarsening of crystal grains and maintain toughness. However, when the addition is excessive, the above result saturates, so V is 0.05 to 0.5%, Nb Is limited to the range of 0.01 to 0.1%.

【0007】上記組成には更にS,Pb ,Ca ,Te ,
Bi の一種または二種以上を添加してもよい。該元素は
被削性を向上せしめるものであるが、過剰の添加では上
記効果は飽和する。したがってSは0.02〜0.30
重量%,Pb は0.01〜0.10重量%,Ca は0.
0003〜0.005重量%,Te は0.005〜0.
1 0重量%,Bi は0.01〜0.10重量%の範囲に
限定する。
The above composition further includes S, Pb, Ca, Te,
You may add 1 type (s) or 2 or more types of Bi. Although this element improves machinability, the above effect is saturated when added in excess. Therefore, S is 0.02 to 0.30
% By weight, Pb is 0.01 to 0.10% by weight, and Ca is 0.1.
0003 to 0.005% by weight, Te 0.005 to 0.
10 wt% and Bi are limited to the range of 0.01 to 0.10 wt%.

【0008】本発明鋼を浸炭窒化処理するには炭素源と
して例えばメタンガス、エタンガス、プロパンガス等の
炭素含有ガスを使用し、窒素源として窒素ガス、アンモ
ニアガス等の窒素含有ガスを用い通常850〜950℃
で浸炭を行なった後、800〜900℃で浸炭窒化処理
を行なう。しかし浸炭窒化を行なった後浸炭を行なって
もよく、またプラズマ浸炭窒化を行なってもよい。更に
浸炭期と浸炭窒化期に分けることなく、浸炭窒化を行な
っても構わない。浸炭窒化処理後は油焼入れを行なう
が、変態点以下に温度を下げてから更に昇温焼入れを行
なってもよい。
For carbonitriding the steel of the present invention, a carbon-containing gas such as methane gas, ethane gas or propane gas is used as a carbon source, and a nitrogen-containing gas such as nitrogen gas or ammonia gas is used as a nitrogen source. 950 ° C
After carburizing in, carbonitriding is performed at 800 to 900 ° C. However, carbonitriding may be performed after carbonitriding, or plasma carbonitriding may be performed. Further, carbonitriding may be performed without dividing into a carburizing period and a carbonitriding period. Oil quenching is performed after the carbonitriding treatment, but it is also possible to further lower the temperature below the transformation point and then perform temperature-controlled quenching.

【0009】[0009]

【実施例】表1に供試材の組成を示す。EXAMPLES Table 1 shows the composition of the test materials.

【表1】 [Table 1]

【0010】上記供試材に対して炭素源としてプロパン
ガスを使用し、窒素源としてアンモニアガスを使用して
920℃,4時間の浸炭窒化処理を行ない(ステージ
I)、その後850℃,1時間の浸炭処理を行なった
(ステージII)。浸炭窒化処理後は100℃の油焼入れ
を行ない、次いで160℃,2時間の焼もどしを行なっ
て試験試料とする。上記試験試料に対して下記の性能試
験を行なった。 1.107 回回転曲げ:切欠試験片の形状係数を1.9
とし疲れ限度を測定する。 2.ローラーピッチング試験:面圧3500MPa,すべ
り−35%で行なった。 性能試験の結果は表2に示される。
Carbonitriding treatment was performed on the above-mentioned test material using propane gas as a carbon source and ammonia gas as a nitrogen source at 920 ° C. for 4 hours (stage I), and then at 850 ° C. for 1 hour. Was carburized (stage II). After carbonitriding, oil quenching at 100 ° C. is performed, and then tempering at 160 ° C. for 2 hours is performed to obtain a test sample. The following performance tests were conducted on the above test samples. 1.10 7- fold rotation bending: The shape factor of the notched test piece was 1.9.
And measure the fatigue limit. 2. Roller pitching test: A surface pressure of 3500 MPa and a slip of -35% were used. The results of the performance test are shown in Table 2.

【0011】[0011]

【表2】 [Table 2]

【0012】表2を参照すると本発明鋼はいずれも表面
硬さは800Hv以上に増大しており、107 回疲れ限
度は550以上、ローラーピッチング寿命は8.5×1
6以上と云う良好な曲げ、疲れ、および面疲れ特性を
示すが、比較鋼は何れも表面硬さが760Hv以下で増
大しておらず、曲げ、疲れ、および面疲れ特性ともに不
充分である。
Referring to Table 2, in all the steels of the present invention, the surface hardness is increased to 800 Hv or more, the fatigue limit of 10 7 times is 550 or more, and the roller pitting life is 8.5 × 1.
Good bending, fatigue, and surface fatigue properties of 0 6 or more are exhibited, but none of the comparative steels has a surface hardness of 760 Hv or less, and the bending, fatigue, and surface fatigue properties are insufficient. .

【0013】[0013]

【発明の効果】したがって本発明においては、浸炭窒化
処理によって優れた曲げ、疲れ、面疲れ特性を示す鋼が
提供される。
As described above, the present invention provides a steel exhibiting excellent bending, fatigue and surface fatigue properties by carbonitriding.

Claims (4)

【特許請求の範囲】[Claims] 【請求項1】C0.15〜0.40重量%,Si 0.1
5重量%以下,Mn 0.40重量%以下,Cr 0.5〜
2.0重量%,Al 0.03〜1.0重量%,N0.0
05〜0.030重量%残余はFe からなる組成を有す
ることを特徴とする浸炭窒化用鋼
1. C0.15 to 0.40% by weight, Si 0.1
5 wt% or less, Mn 0.40 wt% or less, Cr 0.5 to
2.0% by weight, Al 0.03 to 1.0% by weight, N0.0
Steel for carbonitriding, characterized in that it has a composition of Fe in the balance of 05 to 0.030% by weight.
【請求項2】請求項1の組成に更にMo 0.05〜0.
5重量%,Ni 0.1〜1.0重量%,V0.05〜
0.5重量%,Nb 0.01〜0.1重量%の一種また
は二種以上を添加した浸炭窒化用鋼
2. The composition of claim 1 further having a Mo of 0.05 to 0.
5 wt%, Ni 0.1-1.0 wt%, V0.05-
Steel for carbonitriding containing 0.5% by weight and 0.01 to 0.1% by weight of Nb, or one or more of them.
【請求項3】請求項1の組成に更にS0.02〜0.3
0重量%,Pb 0.01〜0.10重量%,Ca 0.0
003〜0.005重量%,Te 0.005〜0.1 0
重量%,Bi 0.01〜0.10重量%の一種または二
種以上を添加した浸炭窒化用鋼
3. The composition of claim 1 further comprising S0.02-0.3.
0% by weight, Pb 0.01 to 0.10% by weight, Ca 0.0
003 to 0.005% by weight, Te 0.005 to 0.10
%, Bi 0.01 to 0.10% by weight, one or two or more carbonitriding steels added
【請求項4】請求項2の組成に更にS0.02〜0.3
0重量%,Pb 0.01〜0.10重量%,Ca 0.0
003〜0.005重量%,Te 0.005〜0.1 0
重量%,Bi 0.01〜0.10重量%の一種または二
種以上を添加した浸炭窒化用鋼
4. The composition of claim 2 further comprising S0.02-0.3.
0% by weight, Pb 0.01 to 0.10% by weight, Ca 0.0
003 to 0.005% by weight, Te 0.005 to 0.10
%, Bi 0.01 to 0.10% by weight, one or two or more carbonitriding steels added
JP6928193A 1993-03-03 1993-03-03 Carbo-nitriding steel Withdrawn JPH06256898A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP6928193A JPH06256898A (en) 1993-03-03 1993-03-03 Carbo-nitriding steel

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP6928193A JPH06256898A (en) 1993-03-03 1993-03-03 Carbo-nitriding steel

Publications (1)

Publication Number Publication Date
JPH06256898A true JPH06256898A (en) 1994-09-13

Family

ID=13398095

Family Applications (1)

Application Number Title Priority Date Filing Date
JP6928193A Withdrawn JPH06256898A (en) 1993-03-03 1993-03-03 Carbo-nitriding steel

Country Status (1)

Country Link
JP (1) JPH06256898A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012073896A1 (en) * 2010-11-29 2012-06-07 住友金属工業株式会社 Rolled steel bar or wire for hot forging

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012073896A1 (en) * 2010-11-29 2012-06-07 住友金属工業株式会社 Rolled steel bar or wire for hot forging
JP5333682B2 (en) * 2010-11-29 2013-11-06 新日鐵住金株式会社 Rolled steel bar or wire rod for hot forging
JPWO2012073896A1 (en) * 2010-11-29 2014-05-19 新日鐵住金株式会社 Rolled steel bar or wire rod for hot forging

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