JP2000063935A - Production of nitrided part - Google Patents

Production of nitrided part

Info

Publication number
JP2000063935A
JP2000063935A JP10234315A JP23431598A JP2000063935A JP 2000063935 A JP2000063935 A JP 2000063935A JP 10234315 A JP10234315 A JP 10234315A JP 23431598 A JP23431598 A JP 23431598A JP 2000063935 A JP2000063935 A JP 2000063935A
Authority
JP
Japan
Prior art keywords
less
hardness
core
treatment
steel
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.)
Pending
Application number
JP10234315A
Other languages
Japanese (ja)
Inventor
Tatsuo Fukuzumi
達夫 福住
Miki Watanabe
幹 渡邊
Mitsuki Minoguchi
光樹 蓑口
Original Assignee
Mitsubishi Seiko Muroran Tokushuko Kk
三菱製鋼室蘭特殊鋼株式会社
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 Mitsubishi Seiko Muroran Tokushuko Kk, 三菱製鋼室蘭特殊鋼株式会社 filed Critical Mitsubishi Seiko Muroran Tokushuko Kk
Priority to JP10234315A priority Critical patent/JP2000063935A/en
Publication of JP2000063935A publication Critical patent/JP2000063935A/en
Pending legal-status Critical Current

Links

Abstract

PROBLEM TO BE SOLVED: To provide a material having the strength equal to that of carburizing treated parts at the time of producing parts with a shape easy to be influenced by heat treating distortion and to provide a heat treating method. SOLUTION: A member produced by nitriding steel contg., by weight, 0.20 to 0.50% C, 0.05 to 2.00% Si, 0.30 to 2.50% Mn, <=0.030% P, 0.20 to 2.50% Cr, 0.05 to 0.50% V, 0.010 to 0.150% Al <=0.0020% O 0.0050 to 0.0200% N, one or more kinds among <=2.00% Ni, <=2.00% Mo, <=0.50% Cu, <=0.050% Nb, <=0.050% Ti and <=0.0025% B, and the balance Fe with inevitable impurities is subjected to softening treatment such as annealing treatment to control the hardness of the core part to <=200 HV and is thereafter subjected to working, and the member after the working is heated at the temp. equal to or above the AC3, is cooled at a cooling rate of 0.1 to 1.0 deg.C/sec to control the core part hardness to >=300 HV and is thereafter subjected to nitriding treatment.

Description

【発明の詳細な説明】Detailed Description of the Invention
【0001】[0001]
【発明の属する技術分野】本発明は、機械構造用部品に
使用される部品の製造方法に関するものである。本発明
を用いることにより熱処理歪みが小さく、加工コストが
安価で、浸炭部品と同等以上の強度特性を有する部品を
製造することが可能となる。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a component used for a machine structural component. By using the present invention, it is possible to manufacture a part that has a small heat treatment distortion, a low processing cost, and strength characteristics equal to or higher than those of a carburized part.
【0002】[0002]
【従来の技術】従来、自動車用部品、機械構造用部品等
には肌焼鋼を浸炭焼入れ・焼戻しした部品が多く使用さ
れている。部品によっては焼入れ・焼戻しの際の熱処理
歪みが問題とされるものがあり、熱処理歪みの発生防止
を目的とした材料および製造方法が実施されている。
2. Description of the Related Art Conventionally, carburized and tempered parts of case-hardening steel are often used for automobile parts, machine structural parts and the like. Some parts have a problem of heat treatment distortion at the time of quenching and tempering, and materials and manufacturing methods for preventing occurrence of heat treatment distortion are implemented.
【0003】熱処理歪みの発生防止を目的とした材料は
低歪み浸炭用鋼として提案されている。しかしながら、
歪みの発生を完全に無くすことは不可能で、熱処理歪み
の影響を受けやすい形状の部品、例えば、肉厚の薄い円
筒形状の部品への適用は困難であった。
A material intended to prevent the occurrence of heat treatment strain has been proposed as a low strain carburizing steel. However,
It is impossible to completely eliminate the occurrence of strain, and it has been difficult to apply it to parts having a shape that is easily affected by heat treatment distortion, for example, a thin cylindrical part.
【0004】そこで、製造方法により熱処理歪みの発生
を防止する方法が実施されている。浸炭後直接焼入れを
せずに、一旦炉冷し、部品表面の炭素濃度を上昇させた
上で、部品を芯金などで固定し、再度加熱し焼入れする
製造方法(以下、浸炭なまし後芯金焼入れ処理)であ
る。この製造方法によれば、熱処理歪みの影響を受けや
すい形状の部品でも熱処理歪みが小さくなり、適用可能
となった。
Therefore, a method for preventing the occurrence of heat treatment distortion by a manufacturing method is implemented. After carburizing, without directly quenching, the furnace is once cooled, the carbon concentration on the surface of the component is increased, then the component is fixed with a core metal, etc., and then heated again for quenching (hereinafter referred to as carburized after-core Gold quenching process). According to this manufacturing method, the heat treatment strain is reduced even in a component having a shape that is easily affected by the heat treatment strain, and it can be applied.
【0005】また、窒化処理による表面硬化方法も熱処
理歪みを小さくする製造方法として提案されている。
Also, a surface hardening method by nitriding treatment has been proposed as a manufacturing method for reducing strain in heat treatment.
【0006】前者の浸炭なまし後芯金焼入れによる製造
方法では熱処理コストが大きく、後者の窒化処理では窒
化処理前に部品仕上がり形状に加工しなければならな
く、浸炭処理した部品と同様の強度を得るには浸炭部品
と同等の心部硬さの部材を加工することが必要となり、
加工コストが大きくなっていた。
The former manufacturing method by carburizing and annealing after core bar quenching requires a large heat treatment cost, and the latter nitriding treatment requires processing into a finished shape of the component before the nitriding treatment, and the same strength as that of the carburized component is obtained. In order to obtain it, it is necessary to process a member with the same core hardness as the carburized parts,
The processing cost was increasing.
【0007】[0007]
【発明が解決しようとする課題】本発明は熱処理歪みの
影響を受けやすい形状の部品の製造において、浸炭処理
部品と同等の強度を得るのに、従来技術による方法より
も熱処理および加工コストを低減させる製造方法を材料
を含めた製造方法により提供することを目的とする。
According to the present invention, in the manufacture of a part having a shape which is easily affected by heat treatment distortion, the heat treatment and the processing cost are reduced as compared with the conventional method in order to obtain the same strength as the carburized part. It is an object of the present invention to provide a manufacturing method including a material by a manufacturing method including materials.
【0008】[0008]
【課題を解決するための手段】本発明者は、従来技術で
は達成が困難であった上記の課題を解決するため様々な
検討を行った結果、以下の知見を得て本発明に到達し
た。
As a result of various studies to solve the above-mentioned problems that were difficult to achieve by the prior art, the present inventor has arrived at the present invention with the following findings.
【0009】熱処理歪みを低減する表面硬化処理方法と
しては窒化処理が有効であり、また、浸炭なまし後芯金
焼入れ処理と比較して熱処理コストの低減が可能である
ことから、熱処理歪みの影響を受けやすい部品の表面硬
化処理方法としては焼入れ作業工程を伴わない窒化処理
が適当である。
The nitriding treatment is effective as a surface hardening treatment method for reducing the heat treatment distortion, and the heat treatment cost can be reduced as compared with the carburizing and post-core metal quenching treatment. A nitriding treatment that does not involve a quenching work step is suitable as a surface hardening treatment method for parts that are susceptible to damage.
【0010】窒化処理を採用するにあたっては浸炭部品
と同等の強度を持たせるため浸炭部品と同等の心部硬さ
の確保が要求される。一方、切削加工コストを低減する
には200HV以下のような心部硬さが軟らかいことが
要求される。この相反する心部硬さの要求は、窒化処理
部材を軟化処理して心部硬さを低下させた後に切削加工
を行い、その後に焼準することで焼入れによる熱処理歪
みを発生させることなく浸炭部品と同等の心部硬さを確
保する方法で解決することが可能である。
When adopting the nitriding treatment, it is required to secure the core hardness equal to that of the carburized component in order to have the same strength as that of the carburized component. On the other hand, in order to reduce the cutting cost, it is required that the core hardness is 200 HV or less. The contradictory requirements for core hardness are carburizing without causing heat treatment distortion due to quenching by softening the nitriding member to reduce core hardness, then cutting, and then normalizing. It is possible to solve it by a method of ensuring the core hardness equivalent to that of the component.
【0011】切削加工後の焼準で浸炭部品と同等の心部
硬さを得ることができ、かつ、良好な窒化特性を得るた
めには特定の化学成分とすることが必要である。
In order to obtain a core hardness equivalent to that of a carburized part by normalizing after cutting and to obtain good nitriding characteristics, it is necessary to use a specific chemical composition.
【0012】本発明は以上の知見からなされたものであ
って、第1発明は重量%で、C:0.20〜0.50
%、Si:0.05〜2.00%、Mn:0.30〜
2.50%、P:0.030%以下、Cr:0.20〜
2.50%、V:0.05〜0.50%、Al:0.0
10〜0.150%、O:0.0020%以下、N:
0.0050〜0.0200%およびNi:2.00%
以下、Mo:2.00%以下、Cu:0.50%以下、
Nb:0.050%以下、Ti:0.050%以下、
B:0.0025%以下のうち1種又は2種以上を含有
し、残部がFeおよび不可避的な不純物からなる窒化鋼
から製造された部材を軟化処理、例えば焼なまし処理に
より心部硬さを200HV以下とした後に加工を行い、
加工後の部材をAC3温度以上に加熱し、0.1〜1.
0℃/秒の冷却速度で冷却し、心部硬さを300HV以
上とした後に窒化処理を行うことを特徴とする窒化部品
の製造方法で、第2発明は、重量%で、C:0.20〜
0.50%、Si:0.05〜2.00%、Mn:0.
30〜2.50%、P:0.030%以下、Cr:0.
20〜2.50%、V:0.05〜0.50%、Al:
0.010〜0.150%、O:0.0020%以下、
N:0.0050〜0.0200%およびNi:2.0
0%以下、Mo:2.00%以下、Cu:0.50%以
下、Nb:0.050%以下、Ti:0.050%以
下、B:0.0025%以下のうち1種又は2種以上を
含み、さらに、S:0.005〜0.10%、Pb:
0.01〜0.30%、Ca:0.0005〜0.01
%、Zr:0.01〜0.20%、Te:0.001〜
0.050%、Bi:0.01〜0.30%のうち1種
または2種以上を含有し、残部がFeおよび不可避的な
不純物からなる窒化鋼から製造された部材を軟化処理、
例えば焼なまし処理により心部硬さを200HV以下と
した後に加工を行い、加工後の部材をAC3温度以上に
加熱し、0.1〜1.0℃/秒の冷却速度で冷却し、心
部硬さを300HV以上とした後に窒化処理を行うこと
を特徴とする窒化部品の製造方法である。
The present invention has been made based on the above findings, and the first invention is C: 0.20 to 0.50 in% by weight.
%, Si: 0.05 to 2.00%, Mn: 0.30
2.50%, P: 0.030% or less, Cr: 0.20
2.50%, V: 0.05 to 0.50%, Al: 0.0
10 to 0.150%, O: 0.0020% or less, N:
0.0050-0.0200% and Ni: 2.00%
Below, Mo: 2.00% or less, Cu: 0.50% or less,
Nb: 0.050% or less, Ti: 0.050% or less,
B: The hardness of the core portion is softened, for example, annealed, by softening, for example, a member made of nitrided steel containing one or more of 0.0025% or less and the balance of Fe and inevitable impurities. Is set to 200 HV or less and then processed,
The processed member is heated to an AC3 temperature or higher, and 0.1-1.
A second aspect of the present invention is a method for manufacturing a nitrided component, which comprises cooling at a cooling rate of 0 ° C./sec and setting a core hardness to 300 HV or more, and then performing a nitriding treatment. 20 ~
0.50%, Si: 0.05 to 2.00%, Mn: 0.
30 to 2.50%, P: 0.030% or less, Cr: 0.
20 to 2.50%, V: 0.05 to 0.50%, Al:
0.010 to 0.150%, O: 0.0020% or less,
N: 0.0050 to 0.0200% and Ni: 2.0
1% or less of 0% or less, Mo: 2.00% or less, Cu: 0.50% or less, Nb: 0.050% or less, Ti: 0.050% or less, B: 0.0025% or less. Including the above, further, S: 0.005-0.10%, Pb:
0.01-0.30%, Ca: 0.0005-0.01
%, Zr: 0.01 to 0.20%, Te: 0.001 to
0.050%, Bi: 0.01 to 0.30%, one or more kinds are contained, and the balance is made of a steel made of nitrided steel consisting of Fe and unavoidable impurities.
For example, after the core hardness is reduced to 200 HV or less by annealing, processing is performed, the processed member is heated to AC3 temperature or higher, and cooled at a cooling rate of 0.1 to 1.0 ° C./sec. It is a method for manufacturing a nitrided component, which is characterized by performing a nitriding treatment after setting a part hardness to 300 HV or more.
【0013】次に本発明の上記組成および製造工程につ
いて限定理由を説明する。
Next, the reasons for limiting the composition and manufacturing process of the present invention will be described.
【0014】C:Cは強度を確保するために必要な元素
で0.20%以上の含有とする。しかし、0.50%を
超える多量の含有は靭性を低下させる。また、窒化処理
の際にNが入りにくくなる。したがって、Cの含有量は
0.20〜0.50%の範囲とした。
C: C is an element necessary for ensuring strength, and is contained at 0.20% or more. However, a large content exceeding 0.50% reduces toughness. Further, it becomes difficult for N to enter during the nitriding treatment. Therefore, the content of C is set to the range of 0.20 to 0.50%.
【0015】Si:Siは脱酸のために添加する必要が
ある。また、心部硬さの確保のために添加することが可
能であるが、過剰な添加は軟化処理後の硬さを上昇さ
せ、加工性を悪化させるので0.05〜2.00%とし
た。
Si: Si must be added for deoxidation. Further, it can be added to secure the core hardness, but excessive addition raises the hardness after the softening treatment and deteriorates the workability, so it was made 0.05 to 2.00%. .
【0016】Mn:MnはSiと同様に脱酸のために添
加する。また、心部硬さの確保およびSと結合して被削
性を高めるため0.30%以上の添加が必要である。し
かし、過剰な添加は軟化処理後の硬さを上昇させ、加工
性を悪化させるので2.50%以下とした。
Mn: Mn is added for deoxidation like Si. In addition, 0.30% or more is required to secure the hardness of the core and to improve machinability by combining with S. However, excessive addition increases the hardness after the softening treatment and deteriorates the workability, so the content was made 2.50% or less.
【0017】P:含有量が多くなると、機械的性質、特
に衝撃特性に悪影響をおよぼすので0.030%以下と
した。
P: When the content is high, mechanical properties, particularly impact properties are adversely affected, so the content was made 0.030% or less.
【0018】Ni:心部硬さの確保と靭性の向上のため
に添加することが可能であるが、過剰な添加は軟化処理
後の硬さを上昇させ、加工性を悪化させ、また、コスト
高となるので2.00%以下とした。
Ni: Ni can be added to secure core hardness and improve toughness, but excessive addition increases hardness after softening treatment, deteriorates workability, and reduces cost. Since it becomes high, it is set to 2.00% or less.
【0019】Cr:心部硬さの確保のために添加するこ
とが必要である。また、窒化処理後の表面硬さを上昇さ
せることが可能である。しかし、過剰な添加は軟化処理
後の硬さを上昇させ、加工性を悪化させるので0.20
〜2.50%とした。
Cr: It is necessary to add Cr in order to secure core hardness. Further, it is possible to increase the surface hardness after the nitriding treatment. However, excessive addition raises the hardness after the softening treatment and deteriorates the workability, so 0.20.
˜2.50%.
【0020】Mo:心部硬さの確保と靭性の向上のため
に添加することが可能である。また、窒化処理後の硬化
層深さを上昇させることが可能である。しかし、過剰な
添加は軟化処理後の硬さを上昇させ、加工性を悪化さ
せ、また、コスト高となるので2.00%以下とした。
Mo: Mo can be added to secure the hardness of the core and improve the toughness. Further, it is possible to increase the depth of the hardened layer after the nitriding treatment. However, excessive addition raises the hardness after the softening treatment, deteriorates the workability, and increases the cost, so the content was made 2.00% or less.
【0021】Cu:心部硬さの確保のために添加するこ
とが可能である。しかし、過剰な添加は熱間加工性を悪
化させる。また、靭性が低下するので0.50%以下と
した。
Cu: It is possible to add Cu to secure the hardness of the core. However, excessive addition deteriorates hot workability. Further, since the toughness decreases, the content is set to 0.50% or less.
【0022】V:心部硬さの確保のために添加する必要
がある。また、窒化処理後の硬化層深さを上昇させるこ
とが可能である。しかし、過剰な添加は軟化処理後の硬
さを上昇させ、加工性を悪化させる。また、靭性低下お
よびコスト高となるので0.05〜0.50%とした。
V: Need to be added to secure the hardness of the core. Further, it is possible to increase the depth of the hardened layer after the nitriding treatment. However, excessive addition increases the hardness after the softening treatment and deteriorates the workability. Further, the toughness decreases and the cost increases, so the content is set to 0.05 to 0.50%.
【0023】Nb:炭窒化物を形成することにより結晶
粒を細粒化し、靭性を向上させることが可能である。し
かし、過剰な添加はコスト高となるので0.050%以
下とした。
Nb: By forming a carbonitride, it is possible to make crystal grains finer and improve toughness. However, excessive addition increases cost, so the content was made 0.050% or less.
【0024】Ti:炭窒化物を形成することにより結晶
粒を細粒化し、靭性を向上させることが可能である。し
かし、過剰な添加はコスト高となるので0.050%以
下とした。
By forming Ti: carbonitride, it is possible to make the crystal grains finer and improve the toughness. However, excessive addition increases cost, so the content was made 0.050% or less.
【0025】B:心部硬さの確保のために添加すること
が可能である。しかし、過剰な添加は熱間加工性を悪化
させるので0.0025%以下とした。
B: It can be added to secure the hardness of the core. However, excessive addition deteriorates the hot workability, so the content was made 0.0025% or less.
【0026】Al:AlはNと結合してAlNを生成
し、オーステナイト結晶粒度を細粒化する作用を有する
元素であり、0.010%未満の含有ではその作用が十
分ではない。一方、0.150%を超える含有は窒化層
を脆化させる。従って、0.010〜0.150%の範
囲とした。
Al: Al is an element having a function of combining with N to form AlN and reducing the austenite grain size, and if the content thereof is less than 0.010%, the function is not sufficient. On the other hand, if the content exceeds 0.150%, the nitride layer becomes brittle. Therefore, the range is set to 0.010 to 0.150%.
【0027】O:含有量が多くなると疲労特性に悪影響
をおよぼすので0.0020%以下とした。
O: When the content is large, the fatigue characteristics are adversely affected, so the content was made 0.0020% or less.
【0028】N:Nは窒化物を生成し、オーステナイト
結晶粒度を細粒化する作用を有する元素であり、0.0
050%未満の含有では、その作用が十分ではない。一
方、0.0200%を超える含有ではその作用が飽和し
てしまう。従って、0.0050〜0.0200%の範
囲とした。
N: N is an element having a function of forming a nitride and refining the austenite grain size.
If it is less than 050%, its action is not sufficient. On the other hand, when the content exceeds 0.0200%, the action is saturated. Therefore, the range is 0.0050 to 0.0200%.
【0029】S、Pb、Ca、Zr、Te、Bi:S、
Pb、Ca、Zr、Te、Biは被削性の向上に効果が
ある元素で、必要に応じて単独あるいは重複して含有さ
せることができる。その効果を得るには、Sは0.00
5%、Pbは0.01%、Caは0.0005%、Zr
は0.01%、Teは0.001%、Biは0.01%
以上の含有が必要である。しかし、Sは0.10%、P
bは0.30%、Caは0.01%、Zrは0.20
%、Teは0.050%、Biは0.30%、を超える
含有は靭性を低下させる。従って、Sの含有量は0.0
05〜0.10%、Pbの含有量は0.01〜0.30
%、Caの含有量は0.0005〜0.01%、Zrの
含有量は0.01〜0.20%、Teの含有量は0.0
01〜0.050%、Biの含有量は0.01〜0.3
0%範囲とした。
S, Pb, Ca, Zr, Te, Bi: S,
Pb, Ca, Zr, Te, and Bi are elements effective in improving machinability, and can be contained alone or in duplicate if necessary. To obtain that effect, S is 0.00
5%, Pb 0.01%, Ca 0.0005%, Zr
0.01%, Te 0.001%, Bi 0.01%
The above contents are required. However, S is 0.10%, P
b is 0.30%, Ca is 0.01%, Zr is 0.20
%, Te is 0.050%, Bi is 0.30%, and the content exceeding these decreases toughness. Therefore, the S content is 0.0
05-0.10%, Pb content is 0.01-0.30
%, The content of Ca is 0.0005 to 0.01%, the content of Zr is 0.01 to 0.20%, and the content of Te is 0.0.
01-0.050%, Bi content 0.01-0.3
The range was 0%.
【0030】軟化処理:上記化学組成範囲の鋼材は圧延
後また熱間鍛造後に空冷した場合、心部硬さが高硬度と
なるため、その部材をそのまま加工するとコスト高とな
る。部材の加工を低コストとするため、軟化処理を実施
することにより心部硬さを200HV以下にすることが
必要である。焼鈍、球状化焼鈍、サイクルアニーリン
グ、圧延後の制御冷却など部材の硬さが低下する処理方
法であれば軟化処理の方法は問わない。また、心部硬さ
を200HV以下としたのは、200HVを越えると後
工程の加工において加工コストが大きくなるからであ
る。
Softening treatment: When a steel material having the above chemical composition range is air-cooled after rolling or hot forging, the hardness of the core portion becomes high, so that if the member is directly processed, the cost becomes high. In order to reduce the cost of processing the member, it is necessary to reduce the core hardness to 200 HV or less by performing the softening treatment. Any softening method may be used as long as it is a processing method such as annealing, spheroidizing annealing, cycle annealing, and controlled cooling after rolling, which reduces the hardness of the member. The reason why the core hardness is set to 200 HV or less is that if the hardness exceeds 200 HV, the processing cost will increase in the subsequent processing.
【0031】加工:窒化処理品の形状に仕上げるため、
部材の加工が必要である。切削加工、冷間鍛造、冷間引
き抜きなど窒化処理品の形状に仕上げることが可能な加
工方法であれば方法は問わない。
Processing: In order to finish the shape of the nitrided product,
Processing of the member is necessary. Any method may be used as long as it is a processing method capable of finishing the shape of the nitrided product such as cutting, cold forging, and cold drawing.
【0032】加工後の熱処理:軟化処理、加工を実施し
た部材をそのまま窒化処理した場合、浸炭部品同等以上
の心部硬さが得られないため、加工後に熱処理し、心部
硬さを300HV以上にすることが必要である。本発明
鋼を用いれば、AC3温度以上に加熱し、0.1〜1.
0℃/秒の冷却速度で冷却することにより300HV以
上の心部硬さが得られる。加熱中の雰囲気はスケールが
発生しない無酸化雰囲気が望ましいが、酸化雰囲気であ
っても焼準後にスケール除去を行うことで適用可能とな
る。また、熱処理後の硬さを300HV以上としたの
は、浸炭部品の心部硬さを想定しているためである。
Heat treatment after working: When a softened and worked member is subjected to nitriding treatment as it is, a core hardness equal to or higher than that of a carburized part cannot be obtained. It is necessary to When the steel of the present invention is used, the steel is heated to an AC3 temperature or higher to 0.1-1.
By cooling at a cooling rate of 0 ° C./sec, a core hardness of 300 HV or higher can be obtained. The atmosphere during heating is preferably a non-oxidizing atmosphere in which no scale is generated, but even an oxidizing atmosphere can be applied by removing the scale after normalizing. The hardness after heat treatment is set to 300 HV or more because the core hardness of the carburized part is assumed.
【0033】窒化処理:ガス窒化、塩浴窒化、ガス軟窒
化、イオン窒化のいずれによってもよく、限定しない。
Nitriding treatment: Any of gas nitriding, salt bath nitriding, gas soft nitriding, and ion nitriding may be used without limitation.
【0034】[0034]
【発明の実施の形態】次に実施例を比較鋼と対比して説
明する。
BEST MODE FOR CARRYING OUT THE INVENTION Next, examples will be described in comparison with comparative steels.
【0035】実施例1 表1に示す化学組成の鋼を溶解し、作成した鋼塊を直径
100mm丸棒に鍛伸したものを供試材とした。表1に
おいて1〜17鋼は本発明鋼であり、1〜10は第1発
明鋼、11〜17は第2発明鋼である。また、18〜2
4鋼は比較鋼である。
Example 1 Steels having the chemical compositions shown in Table 1 were melted, and the prepared ingots were forged into a round bar having a diameter of 100 mm, which was used as a test material. In Table 1, 1 to 17 steels are the present invention steels, 1 to 10 are the first invention steels, and 11 to 17 are the second invention steels. Also, 18-2
Steel No. 4 is a comparative steel.
【0036】[0036]
【表1】 [Table 1]
【0037】供試材を900℃に加熱後、炉中にて50
℃/hrの冷却速度で室温まで冷却することにより軟化
処理し、その心部硬さを測定した。軟化処理した部材を
外径90mm、内径80mm、高さ70mmの円筒形に
切削加工した。円筒形部品を窒素雰囲気中で900℃に
加熱後、室温まで空冷し(平均冷却速度0.15℃/
秒)、その心部硬さを測定した。表2に軟化処理後の心
部硬さの測定結果および加工後の熱処理後の心部硬さの
測定結果を示す。
After heating the test material to 900 ° C., 50 in a furnace
The core was softened by cooling to room temperature at a cooling rate of ° C / hr, and its core hardness was measured. The softened member was cut into a cylindrical shape having an outer diameter of 90 mm, an inner diameter of 80 mm and a height of 70 mm. The cylindrical part was heated to 900 ° C in a nitrogen atmosphere and then air-cooled to room temperature (average cooling rate 0.15 ° C /
Second), and the hardness of the core was measured. Table 2 shows the measurement results of the core hardness after the softening treatment and the core hardness after the heat treatment after processing.
【0038】[0038]
【表2】 [Table 2]
【0039】表2の結果から明らかなように比較鋼であ
る18〜24鋼を本発明鋼と比較すると、18鋼はC含
有量が少ないため加工後の熱処理後の心部硬さが300
HVより低く、19鋼、20鋼、21鋼、22鋼、23
鋼、24鋼はそれぞれSi、Mn、Ni、Cr、Mo、
V含有量が高いため軟化処理後の心部硬さが200HV
より高くなっているものである。
As is clear from the results shown in Table 2, when the comparative steels 18 to 24 are compared with the steels of the present invention, since the 18 steel has a small C content, the core hardness after heat treatment after working is 300.
Lower than HV, 19 steel, 20 steel, 21 steel, 22 steel, 23
Steel, 24 steel are Si, Mn, Ni, Cr, Mo,
Core content after softening is 200 HV due to high V content
It is higher.
【0040】実施例2 表3に示す化学組成の鋼を溶解し、作製した鋼塊を直径
100mm丸棒に鍛伸したものを供試材とした。表3に
おいて、25、26鋼は本発明鋼であり、25鋼は第1
発明鋼、26鋼は第2発明鋼である。また、27鋼は浸
炭なまし後芯金焼入れ処理に使用されている現用鋼であ
る。
Example 2 Steels having the chemical compositions shown in Table 3 were melted, and the produced steel ingots were forged into a round bar having a diameter of 100 mm, which was used as a test material. In Table 3, 25 and 26 steels are steels of the present invention, and 25th steel is the first steel.
Invention Steel and 26 Steel are second invention steels. Further, No. 27 steel is the current steel used for the carburizing and annealing after core bar quenching.
【0041】[0041]
【表3】 [Table 3]
【0042】本発明鋼25、26鋼の供試材については
900℃に加熱後、炉中にて50℃/hrの冷却速度で
室温まで冷却することにより軟化処理した。この軟化処
理した部材を図1に示す形状に切削加工した。この部品
を窒素雰囲気中で900℃に加熱後、室温まで空冷(平
均冷却速度0.15℃/秒)した。そして、570℃×
3hrのガス軟窒化処理を施した。現用鋼27鋼の供試
材については焼ならし後、図1に示す形状に切削加工し
た。この部品2個製作し、一方は浸炭なまし後芯金焼入
れを実施、もう一方は通常の浸炭処理を実施した。
The test materials of the invention steels 25 and 26 were softened by heating them to 900 ° C. and then cooling them to room temperature at a cooling rate of 50 ° C./hr in a furnace. This softened member was cut into the shape shown in FIG. This part was heated to 900 ° C. in a nitrogen atmosphere and then air-cooled to room temperature (average cooling rate 0.15 ° C./sec). And 570 ℃ ×
The gas soft nitriding treatment was performed for 3 hours. The test material of the current steel 27 steel was normalized and then cut into the shape shown in FIG. Two of these parts were manufactured, one of which was carburized and then cored and quenched, and the other of which was subjected to normal carburizing treatment.
【0043】表4に表面硬化処理後の各供試材の心部硬
さ、表面硬さ、500HVまでの硬化層深さおよび供試
材の外周の歪み変形量の測定結果を示す。この結果から
明らかなように本発明による製造方法によって製造され
た部品は浸炭処理部品と同等の特性を有しており、熱処
理歪みについても減少している。
Table 4 shows the measurement results of the core hardness, the surface hardness, the depth of the hardened layer up to 500 HV, and the strain deformation amount of the outer circumference of each test material after the surface hardening treatment. As is clear from this result, the parts manufactured by the manufacturing method according to the present invention have the same characteristics as the carburized parts, and the heat treatment distortion is also reduced.
【0044】[0044]
【表4】 [Table 4]
【0045】[0045]
【発明の効果】以上説明したように、本発明鋼を本発明
方法により製造することによって熱処理歪みが小さく、
加工コストが安価で浸炭部品と同等以上の強度特性を有
する部品を製造することができる。
As described above, when the steel of the present invention is manufactured by the method of the present invention, the heat treatment strain is small,
It is possible to manufacture a component which has a low processing cost and has strength characteristics equal to or higher than those of the carburized component.
【図面の簡単な説明】[Brief description of drawings]
【図1】実施例2の試験に供した試料の寸法を示す斜視
図である。
FIG. 1 is a perspective view showing dimensions of a sample used in a test of Example 2.
───────────────────────────────────────────────────── 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) C22C 38/58 C22C 38/58 (72)発明者 蓑口 光樹 北海道室蘭市仲町12番地 三菱製鋼室蘭特 殊鋼株式会社室蘭製作所内 Fターム(参考) 4K028 AA02 AB01 AC08 ─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. 7 Identification code FI theme code (reference) C22C 38/58 C22C 38/58 (72) Inventor Mitsuki Minoguchi 12 Nakamachi, Muroran-shi, Hokkaido Mitsubishi Steel Muroran Special Steel Muroran Manufacturing Co., Ltd. F-term (reference) 4K028 AA02 AB01 AC08

Claims (2)

    【特許請求の範囲】[Claims]
  1. 【請求項1】 重量%で、C:0.20〜0.50%、
    Si:0.05〜2.00%、Mn:0.30〜2.5
    0%、P:0.030%以下、Cr:0.20〜2.5
    0%、V:0.05〜0.50%、Al:0.010〜
    0.150%、O:0.0020%以下、N:0.00
    50〜0.0200%およびNi:2.00%以下、M
    o:2.00%以下、Cu:0.50%以下、Nb:
    0.050%以下、Ti:0.050%以下、B:0.
    0025%以下のうち1種又は2種以上を含有し、残部
    がFeおよび不可避的な不純物からなる窒化鋼から製造
    された部材を軟化処理、例えば焼なまし処理により心部
    硬さを200HV以下とした後に加工を行い、加工後の
    部材をAC3温度以上に加熱し、0.1〜1.0℃/秒
    の冷却速度で冷却し、心部硬さを300HV以上とした
    後に窒化処理を行うことを特徴とする窒化部品の製造方
    法。
    1. C: 0.20 to 0.50% by weight,
    Si: 0.05 to 2.00%, Mn: 0.30 to 2.5
    0%, P: 0.030% or less, Cr: 0.20 to 2.5
    0%, V: 0.05 to 0.50%, Al: 0.010
    0.150%, O: 0.0020% or less, N: 0.00
    50 to 0.0200% and Ni: 2.00% or less, M
    o: 2.00% or less, Cu: 0.50% or less, Nb:
    0.050% or less, Ti: 0.050% or less, B: 0.
    A member made of nitriding steel containing one or two or more of 0025% or less and the balance being Fe and inevitable impurities has a core hardness of 200 HV or less by softening treatment, for example, annealing treatment. After that, it is processed, the processed member is heated to AC3 temperature or higher, cooled at a cooling rate of 0.1 to 1.0 ° C./sec, and the core hardness is set to 300 HV or higher, and then nitriding is performed. A method for manufacturing a nitrided part, comprising:
  2. 【請求項2】 重量%で、C:0.20〜0.50%、
    Si:0.05〜2.00%、Mn:0.30〜2.5
    0%、P:0.030%以下、Cr:0.20〜2.5
    0%、V:0.05〜0.50%、Al:0.010〜
    0.150%、O:0.0020%以下、N:0.00
    50〜0.0200%およびNi:2.00%以下、M
    o:2.00%以下、Cu:0.50%以下、Nb:
    0.050%以下、Ti:0.050%以下、B:0.
    0025%以下のうち1種又は2種以上を含み、さら
    に、S:0.005〜0.10%、Pb:0.01〜
    0.30%、Ca:0.0005〜0.01%、Zr:
    0.01〜0.20%、Te:0.001〜0.050
    %、Bi:0.01〜0.30%のうち1種または2種
    以上を含有し、残部がFeおよび不可避的な不純物から
    なる窒化鋼から製造された部材を軟化処理、例えば焼な
    まし処理により心部硬さを200HV以下とした後に加
    工を行い、加工後の部材をAC3温度以上に加熱し、
    0.1〜1.0℃/秒の冷却速度で冷却し、心部硬さを
    300HV以上とした後に窒化処理を行うことを特徴と
    する窒化部品の製造方法。
    2. C: 0.20 to 0.50% by weight,
    Si: 0.05 to 2.00%, Mn: 0.30 to 2.5
    0%, P: 0.030% or less, Cr: 0.20 to 2.5
    0%, V: 0.05 to 0.50%, Al: 0.010
    0.150%, O: 0.0020% or less, N: 0.00
    50 to 0.0200% and Ni: 2.00% or less, M
    o: 2.00% or less, Cu: 0.50% or less, Nb:
    0.050% or less, Ti: 0.050% or less, B: 0.
    One or more of 0025% or less are included, and further S: 0.005 to 0.10%, Pb: 0.01 to.
    0.30%, Ca: 0.0005 to 0.01%, Zr:
    0.01-0.20%, Te: 0.001-0.050
    %, Bi: 0.01 to 0.30%, one or more of which are contained, and the balance made of a nitrided steel made of Fe and inevitable impurities is softened, for example, annealed. After the core hardness is set to 200 HV or less, processing is performed, and the processed member is heated to AC3 temperature or higher,
    A method for producing a nitrided component, which comprises cooling at a cooling rate of 0.1 to 1.0 ° C./second and setting a core hardness to 300 HV or more, and then performing a nitriding treatment.
JP10234315A 1998-08-20 1998-08-20 Production of nitrided part Pending JP2000063935A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
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Application Number Priority Date Filing Date Title
JP10234315A JP2000063935A (en) 1998-08-20 1998-08-20 Production of nitrided part

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Publication Number Publication Date
JP2000063935A true JP2000063935A (en) 2000-02-29

Family

ID=16969092

Family Applications (1)

Application Number Title Priority Date Filing Date
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Country Status (1)

Country Link
JP (1) JP2000063935A (en)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006063378A (en) * 2004-08-26 2006-03-09 Daido Steel Co Ltd Method for producing machine parts with cold-forging and soft-nitriding
EP1803831A2 (en) * 2005-12-28 2007-07-04 HONDA MOTOR CO., Ltd. Nitrocarburized microalloyed steel member
US7622009B2 (en) 2001-03-21 2009-11-24 Honda Giken Kogyo Kabushiki Kaisha Steel material
US7655100B2 (en) 2001-03-21 2010-02-02 Honda Giken Kogyo Kabushiki Kaisha Method for preparation of steel material
JP2011179048A (en) * 2010-02-26 2011-09-15 Jfe Steel Corp Steel for carburizing having excellent cold workability
JP2014019920A (en) * 2012-07-20 2014-02-03 Nippon Steel & Sumitomo Metal Steel material for carburized or carbonitrided component
US9127342B2 (en) 2011-09-19 2015-09-08 Hyundai Motor Company High-strength transmission gear and method of manufacturing the same
CN109790591A (en) * 2016-10-13 2019-05-21 卡特彼勒公司 A kind of nitridation track pin for machine track chain component
JP6525115B1 (en) * 2018-06-27 2019-06-05 日本製鉄株式会社 Nitriding bars and machine parts

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7622009B2 (en) 2001-03-21 2009-11-24 Honda Giken Kogyo Kabushiki Kaisha Steel material
US7655100B2 (en) 2001-03-21 2010-02-02 Honda Giken Kogyo Kabushiki Kaisha Method for preparation of steel material
JP2006063378A (en) * 2004-08-26 2006-03-09 Daido Steel Co Ltd Method for producing machine parts with cold-forging and soft-nitriding
JP4507763B2 (en) * 2004-08-26 2010-07-21 大同特殊鋼株式会社 Manufacturing method of machine parts by cold forging-soft nitriding
EP1803831A2 (en) * 2005-12-28 2007-07-04 HONDA MOTOR CO., Ltd. Nitrocarburized microalloyed steel member
EP1803831A3 (en) * 2005-12-28 2011-02-23 Honda Motor Co., Ltd. Nitrocarburized microalloyed steel member
JP2011179048A (en) * 2010-02-26 2011-09-15 Jfe Steel Corp Steel for carburizing having excellent cold workability
US9127342B2 (en) 2011-09-19 2015-09-08 Hyundai Motor Company High-strength transmission gear and method of manufacturing the same
JP2014019920A (en) * 2012-07-20 2014-02-03 Nippon Steel & Sumitomo Metal Steel material for carburized or carbonitrided component
CN109790591A (en) * 2016-10-13 2019-05-21 卡特彼勒公司 A kind of nitridation track pin for machine track chain component
JP6525115B1 (en) * 2018-06-27 2019-06-05 日本製鉄株式会社 Nitriding bars and machine parts
WO2020003425A1 (en) * 2018-06-27 2020-01-02 日本製鉄株式会社 Reinforcing bar for nitriding, and machine component

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