Steel for nitrocarburizing, nitrocarburized steel part, and producing method of nitrocarburized steel part

Patent metadata

Field	Value
Publication number	US-9284632-B2
Application number	US-201113138992-A
Country	US
Kind code	B2
Filing date	Jan 25, 2011
Priority date	Mar 16, 2010
Publication date	Mar 15, 2016
Grant date	Mar 15, 2016

Abstract

Steel for nitrocarburizing includes, by mass %, C: 0% to less than 0.15%; Si: 0.01% to 1.00%; Mn: 0.01% to 1.00%; S: 0.0001% to 0.050%; Al: 0.0001% to 0.050%; Ti: more than 0.50% to 1.50%; N: 0.0005% to 0.0100%; and the balance consisting of Fe and inevitable impurities, in which P is limited to 0.050% or less; O is limited to 0.0060% or less; and the amount of Ti [Ti %], the amount of C [C %], the amount of N [N %], and the amount of S [S %] satisfy 0.48<[Ti %]−47.9×([C %]/12+[N %]/14+[S %]/32)≦1.20.

First claim

What is claimed is:

1. A steel for nitrocarburizing, consisting of, by mass %:
C: 0% to 0.067%;
Si: 0.01% to 1.00%;
Mn: 0.29% to 1.00%;
S: 0.0001% to 0.050%;
Al: 0.0001% to 0.050%;
Ti: more than 0.50% to 1.50%;
N: 0.0005% to 0.0100%; and
a balance consisting of Fe and inevitable impurities,
wherein P is limited to 0.050% or less;
O is limited to 0.0060% or less; and
an amount of Ti [Ti %], an amount of C [C %], an amount of N [N %], and an amount of S [S %] satisfy 0.48<[Ti %]−47.9×([C %]/12+[N %]/14+[S %]/32)≦1.20.

2. The steel for nitrocarburizing according to claim 1 , wherein the amount of Ti [Ti] is 0.60% to 1.50%.

3. A steel for nitrocarburizing, consisting of, by mass %:
C: 0% to 0.067%;
Si: 0.01% to 1.00%;
Mn: 0.29% to 1.00%;
S: 0.0001% to 0.050%;
Al: 0.0001% to 0.050%;
Ti: more than 0.50% to 1.50%;
N: 0.0005% to 0.0100%;
at least one of
Cr: 0.01% to less than 0.30%;
Mo: 0.01% to 1.00%;
V: 0.005% to 0.50%;
Nb: 0.005% to 0.10%;
Cu: 0.05% to 2.00%;
Ni: 0.05% to less than 2.00%; or
B: 0.0005% to 0.0050%; and

a balance consisting of Fe and inevitable impurities,
wherein P is limited to 0.050% or less;
O is limited to 0.0060% or less; and
an amount of Ti [Ti %], an amount of C [C %], an amount of N [N %], and an amount of S [S %] satisfy 0.48<[Ti %]−47.9×([C %]/12+[N %]/14+[S %]/32)≦1.20.

4. The steel for nitrocarburizing according to claim 3 , wherein the amount of Ti [Ti] is 0.60% to 1.50%.

Assignees

• Kubota Manabu
• Nippon Steel & Sumitomo Metal Corp

Inventors

• Kubota Manabu

Classifications

• C21D8/1255

  with diffusion of elements, e.g. decarburising, nitriding · CPC title

• C22C38/50 Primary

  with titanium or zirconium · CPC title

• C22C38/02 Primary

  containing silicon · CPC title

• C22C38/12

  containing tungsten, tantalum, molybdenum, vanadium, or niobium · CPC title

• C22C38/42

  with copper · CPC title