公开(公告)号：EP1201773B1

公开(公告)日：2009-04-22

申请号：EP00937195.6

申请日：2000-06-08

Applicant: NHK SPRING CO., LTD.

Inventor： TANGE, Akira ,  ANDO, Kotoji ,  WATANABE, Koji

IPC: C21D7/06

CPC classification number: C21D9/02 ,  C21D7/06 ,  F16F1/021 ,  F16F2226/00 ,  Y10S148/908 ,  Y10T29/479

Abstract: Spring steel having a hardness expressed by a Brinell ball indentation diameter of at least 2.7 mm is kept insulated at 150 to 350 DEG C, and is subjected to warm stress peening with a stress given to the spring steel at the above temperature.

公开(公告)号：EP1201773A9

公开(公告)日：2002-07-31

申请号：EP00937195.6

申请日：2000-06-08

Applicant: NHK Spring Co., Ltd.

Inventor： TANGE, Akira ,  ANDO, Kotoji ,  WATANABE, Koji

IPC: C21D7/06

CPC classification number: C21D9/02 ,  C21D7/06 ,  F16F1/021 ,  F16F2226/00 ,  Y10S148/908 ,  Y10T29/479

Abstract: In a production process for highly strengthened springs, the process comprises performing a first shot peening to a spring steel having a hardness of a diameter of 2.7 mm or less on a Brinell ball mark while applying stress to the springs at a warm temperature in the range of 150 to 350°C.

公开(公告)号：EP1201773A1

公开(公告)日：2002-05-02

申请号：EP00937195.6

申请日：2000-06-08

Applicant: NHK Spring Co., Ltd.

Inventor： TANGE, Akira ,  ANDO, Kotoji ,  WATANABE, Koji

IPC: C21D7/06

CPC classification number: C21D9/02 ,  C21D7/06 ,  F16F1/021 ,  F16F2226/00 ,  Y10S148/908 ,  Y10T29/479

Abstract: In a production process for highly strengthened springs, the process comprises performing a first shot peening to a spring steel having a hardness of a diameter of 2.7 mm or less on a Brinell ball mark while applying stress to the springs at a warm temperature in the range of 150 to 350°C.