Method for producing steel component

Patent metadata

Field	Value
Publication number	US-9410232-B2
Application number	US-201214352829-A
Country	US
Kind code	B2
Filing date	Oct 31, 2012
Priority date	Nov 1, 2011
Publication date	Aug 9, 2016
Grant date	Aug 9, 2016

Abstract

A method for producing a steel component by performing the treatments of the following sequentially steps 1 and 2 to a steel material containing, by mass %, C: 0.15 to 0.25%, Si: 0.01 to 0.10%, Mn: 0.50 to 0.80%, S: 0.003 to 0.030%, Cr: 0.80 to 1.20%, Mo: 0.30 to 0.45%, Al: 0.015 to 0.050%, and N: 0.010 to 0.025%, wherein Cr/Mn is 1.3 to 2.4, the balance being Fe and impurities, and contents of P and O among the impurities are P: not more than 0.010%, and O: not more than 0.0020%:
step 1: a treatment which holds the steel material at a temperature of 850 to 1000° C. in a carburizing atmosphere or carbonitriding atmosphere, and step 2: a treatment which quenches the carburized or carbonitrided steel material, by using quenching oil having a temperature of 40 to 80° C. and a kinetic viscosity of 20 to 25 mm 2 /s at 40° C.

First claim

What is claimed is:

1. A method for producing a steel component by performing the treatments of the following sequentially steps 1 and 2 to a steel material containing, by mass %,
C: 0.15 to 0.25%,
Si: 0.01 to 0.10%,
Mn: 0.50 to 0.80%,
S: 0.003 to 0.030%,
Cr: 0.80 to 1.20%,
Mo: 0.30 to 0.45%,
Al: 0.015 to 0.050%, and
N: 0.010 to 0.025%, wherein
fn represented by Formula (1) shown below is 1.3 to 2.4, the balance being Fe and impurities, and contents of P and O among the impurities are
P: not more than 0.010%, and
O: not more than 0.0020%:
step 1: a treatment which holds the steel material at a temperature of 850 to 1000° C. in a carburizing atmosphere or carbonitriding atmosphere, and
step 2: a treatment which quenches the carburized or carbonitrided steel material, by using quenching oil having a temperature of 40 to 80° C. and a kinetic viscosity of 20 to 25 mm 2 /s at 40° C.;
fn =Cr/Mn  (1)

where, Cr and Mn in Formula (1) represent the content of each element in mass %.

2. The method for producing a steel component according to claim 1 , wherein the step 1 includes a holding process at a temperature of 850 to 1000° C. in a carburizing atmosphere or carbonitriding atmosphere followed by a holding process at a temperature of 800 to 900° C. in a carburizing atmosphere or carbonitriding atmosphere.

3. The method for producing a steel component according to claim 1 , wherein the steel material contains, in mass %, Nb: not more than 0.08% in lieu of a part of Fe.

Assignees

• Nippon Steel & Sumitomo Metal Corp
• Honda Motor Co Ltd

Inventors

• Horimoto Masayuki
• Imataka Hideki
• Nakaoka Masaomi
• Ninomiya Akihito
• Okada Yoshinari

Classifications

• C22C38/002

  containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60 · CPC title

• C22C38/26

  with niobium or tantalum · CPC title

• C22C38/02

  containing silicon · CPC title

• C22C38/04

  containing manganese · CPC title

• C22C38/00

  Ferrous alloys, e.g. steel alloys (cast-iron alloys C22C37/00) · CPC title