公开(公告)号：EP1801253B1

公开(公告)日：2014-11-05

申请号：EP04772233.5

申请日：2004-08-26

申请人： Daido Tokushuko Kabushiki Kaisha ,  NHK SPRING COMPANY LIMITED

发明人： KIMURA, Kazuyoshi, c/o DAIDO TOKUSHUKO K.K. ,  KOYAMA, Hiroshi ,  TANGE, Akira, c/o NHK Spring Co., Ltd ,  OKUYAMA, Isamu, c/o NHK Spring Co., Ltd ,  HISANO, Yosuke, c/o NHK Spring Co., Ltd ,  YONEGUCHI, Akio, c/o NHK Spring Co., Ltd

IPC分类号： C22C38/00 ,  C22C38/38 ,  C21D8/00 ,  B24C1/10

CPC分类号： F16F1/021 ,  B24C1/10 ,  C22C38/04 ,  C22C38/06 ,  C22C38/34 ,  C22C38/42 ,  C22C38/50

公开(公告)号：EP1801253A1

公开(公告)日：2007-06-27

申请号：EP04772233.5

申请日：2004-08-26

申请人： Daido Tokushuko Kabushiki Kaisha ,  NHK SPRING COMPANY LIMITED

发明人： KIMURA, Kazuyoshi, c/o DAIDO TOKUSHUKO K.K. ,  KOYAMA, Hiroshi ,  TANGE, Akira, c/o NHK Spring Co., Ltd ,  OKUYAMA, Isamu, c/o NHK Spring Co., Ltd ,  HISANO, Yosuke, c/o NHK Spring Co., Ltd ,  YONEGUCHI, Akio, c/o NHK Spring Co., Ltd

IPC分类号： C22C38/00 ,  C22C38/38 ,  C21D8/00 ,  B24C1/10

CPC分类号： F16F1/021 ,  B24C1/10 ,  C22C38/04 ,  C22C38/06 ,  C22C38/34 ,  C22C38/42 ,  C22C38/50

摘要： A high strength spring steel of this invention is characterized in containing, in percent of mass, of C: 0.36-0.48%; Si: 1.80-2.80%; Mn: 0.20-1.40%; P: 0.015% or less; S: 0.010% or less; Cu: 0.10-0.500; Ni: 0.10-2.00%; Cr: 0.05-1.20%; s-Al: 0.005-0.040%; N: 0.002-0.012%; 0: 0.002% or less, while the remainder is constituted of Fe and inevitable impurities and the quantity of inclusions of 10µm or larger in diameter per field of vision of 100mm 2 is 10 or less. A manufacturing method of high strength spring of this invention is characterized in that the high strength spring steel which is tempered to HRC52 or higher is formed into a spring shape by hot forming or cold forming and warm shot peening is carried out so as to produce a high strength spring of 1176 MPa or higher in maximum shearing stress.