Method for improving the structure of a steel component after heating and stell component obtained by the method

Patent metadata

Field	Value
Publication number	US-2016348204-A1
Application number	US-201615163636-A
Country	US
Kind code	A1
Filing date	May 24, 2016
Priority date	May 25, 2015
Publication date	Dec 1, 2016
Grant date	—

Abstract

The present disclosure relates to a method for improving the steel structure of a steel component after heating including the steps of heating the steel component to a temperature of at least 1100° C., quenching the steel component to a temperature above the martensite start temperature (Ms) to form bainite, and maintaining the steel component at that temperature for a holding time sufficient for transformation of all austenite to bainite, re-heating the steel component to a temperature of at least 580° C. but below the Ac 1 transformation temperature, and maintaining the steel component at that temperature for the steel component to exhibit a hardness of 45 Rockwell hardness C or below, and cooling the steel component.

First claim

1 . A method for restoring a steel structure for a steel component after heating characterized in that it comprises the steps of:
a) heating a steel component to a temperature of at least 1100° C., b) quenching the steel component to a temperature above the martensite start temperature (Ms) to form bainite, and maintaining the steel component at that temperature for a holding time sufficient for transformation of all austenite to bainite, c) re-heating the steel ring to a temperature of at least 580° C. but below the Ac 1 transformation temperature, and maintaining the steel ring at that temperature for the steel ring to exhibit a hardness of 45 Rockwell hardness C or below, d) cooling the steel ring.

2 . Method according to claim 1 , characterized in that step a) comprises forming the steel component by hot rolling, forging and/or hot drawing at a temperature of at least 1100° C.

3 . Method according to claim 1 , characterized in that step a) comprises welding the steel component at a temperature of at least 1100° C. to form a welding joint.

4 . Method according to claim 3 , characterized in that the welding joint is a flash butt welded joint.

5 . Method according to claim 1 , characterized in that comprises quenching the steel component to a temperature above Ms and below 450° C. to form bainite, and maintaining the steel component at that temperature for a holding time sufficient for transformation of all austenite to bainite.

6 . Method according to claim 1 , characterized in that step b) comprises quenching the steel component to a temperature of 300 to 350° C. to form bainite, and maintaining the steel component at that temperature for a holding time sufficient for transformation of all austenite to bainite.

7 . Method according to claim 1 , characterized in that the steel component is a high-carbon steel component.

8 . Method according to claim 1 , characterized in that the steel component is a bearing component.

9 . Method according to claim 8 , characterized in that the bearing component is a bearing ring.

10 . Steel component characterized in that it is manufactured using a method for restoring a steel structure for a steel component after heating characterized in that it comprises the steps of
a) heating a steel component to a temperature of at least 1100° C., b) quenching the steel component to a temperature above the martensite start temperature (Ms) to form bainite and maintaining the steel component at that temperature for a holding time sufficient for transformation of all austenite to bainite, c) re-heating the steel ring to a temperature of at least 580° C. but below the Ac 1 transformation temperature, and maintaining the steel ring at that temperature for the steel ring to exhibit a hardness of 45 Rockwell hardness C or below, and d) cooling the steel ring.

11 . Steel component according to claim 10 , characterized in that it is a steel ring.

12 . Steel component according to claim 11 , characterized in that it is a bearing ring.

Assignees

• Skf Ab

Inventors

• Larsson Staffan

Classifications

• F16C33/64

  Special methods of manufacture · CPC title

• F16C33/62

  Selection of substances · CPC title

• F16C2202/04

  Hardness · CPC title

• C22C38/02

  containing silicon · CPC title

• C22C38/04

  containing manganese · CPC title