Bearing steel having improved fatigue durability and method of manufacturing the same

Patent metadata

Field	Value
Publication number	US-10060014-B2
Application number	US-201514918257-A
Country	US
Kind code	B2
Filing date	Oct 20, 2015
Priority date	Nov 21, 2014
Publication date	Aug 28, 2018
Grant date	Aug 28, 2018

Abstract

A bearing steel includes 1.0 to 1.3 wt % carbon; 0.9 to 1.6 wt % silicon; 0.5 to 1.0 wt % manganese; 1.5 to 2.5 wt % nickel; 1.5 to 2.5 wt % chromium; 0.2 to 0.5 wt % molybdenum; 0.01 to 0.06 wt % aluminum; 0.01 to 0.1 wt % copper; at least one selected from the group consisting of more than 0 wt % and less than 0.38 wt % vanadium and more than 0 wt % and less than 0.02 wt % niobium; and a balance of iron.

First claim

What is claimed is:

1. A bearing steel consisting of: based on a total weight of the bearing steel,
1.0 to 1.3 wt % carbon;
0.9 to 1.6 wt % silicon;
0.5 to 1.0 wt % manganese;
1.5 to 2.5 wt % nickel;
1.5 to 2.5 wt % chromium;
0.2 to 0.5 wt % molybdenum;
0.01 to 0.06 wt % aluminum;
0.01 to 0.1 wt % copper;
at least one selected from the group consisting of more than 0 wt % and less than 0.38 wt % vanadium and more than 0 wt % and less than 0.02 wt % niobium; and a balance of iron and inevitable impurities;
wherein the bearing steel is characterized in that spheroidized complex carbides including Me 3 C, Me 7 C 3 , Me 23 C 6 , or MeC carbides, where Me is a metal ion, is contained therein.

2. The bearing steel of claim 1 , wherein the bearing steel contains at most 0.006 wt % nitrogen, 0.001 wt % oxygen, 0.03 wt % phosphorus, and 0.01 wt % sulfur as inevitable impurities.

3. The bearing steel of claim 1 , wherein Me of the MeC carbide is one or more selected from the group consisting of chromium, iron, vanadium, niobium, and molybdenum.

4. The bearing steel of claim 1 , wherein Me of the Me 3 C, Me 7 C 3 , and Me 23 C 6 carbides is at least one selected from the group consisting of chromium, iron, and manganese.

Assignees

• Hyundai Motor Co Ltd

Inventors

• Cha Sung-Chul
• Lee Si-Yup
• Ko Young-Sang
• Bae Moon-Ki
• Hong Seung-Hyun

Classifications

• C21D8/06

  during manufacturing of rods or wires · CPC title

• C21D1/18

  Hardening (C21D1/02 takes precedence); Quenching with or without subsequent tempering (quenching devices C21D1/62) · CPC title

• C21D1/32

  Soft annealing, e.g. spheroidising · CPC title

• C21D9/525

  for wire, for rods (C21D9/54 takes precedence) · CPC title

• C22C38/02 Primary

  containing silicon · CPC title