发明名称 |
Spring and manufacture method thereof |
摘要 |
A spring with superior fatigue resistance is provided by decreasing the material cost while simplifying the production process. Disclosed is a spring including: a composition consisting of, by mass %, 0.5 to 0.7% of C, 1.0 to 2.0% of Si, 0.1 to 1.0% of Mn, 0.1 to 1.0% of Cr, not more than 0.035% of P, not more than 0.035% of S, and the balance of Fe and impurities; a structure including not less than 95% of tempered martensitic structure; a compressive residual stress layer formed to a depth of 0.35 mm to D/4, in which D (mm) is a diameter; the compressive residual stress layer having maximum compressive residual stress of 800 to 2000 MPa; a center portion with Vickers hardness of 550 to 700 HV; and a high hardness layer with greater hardness than the center portion. |
申请公布号 |
US9341223(B2) |
申请公布日期 |
2016.05.17 |
申请号 |
US201214002798 |
申请日期 |
2012.03.01 |
申请人 |
NHK SPRING CO., LTD. |
发明人 |
Suzuki Takeshi;Ono Yoshiki;Kurokawa Shimpei |
分类号 |
F16F1/06;F16F1/02;C21D7/06;C21D9/02;C22C38/02;C22C38/04;C22C38/18;C22C38/34;B21F35/00 |
主分类号 |
F16F1/06 |
代理机构 |
Oliff PLC |
代理人 |
Oliff PLC |
主权项 |
1. A spring comprising:
a composition consisting of, by mass %, 0.5 to 0.7% of C, 1.0 to 2.0% of Si, 0.1 to 1.0% of Mn, 0.1 to 1.0% of Cr, not more than 0.035% of P, not more than 0.035% of S, and the balance of Fe and inevitable impurities; a structure including not less than 95% of tempered martensitic structure by area ratio in a cross section of a wire material; a compressive residual stress layer formed from a surface to a depth of 0.35 mm to D/4, in which D (mm) is a circle-equivalent diameter of a cross section, the compressive residual stress layer having maximum compressive residual stress of 800 to 2000 MPa; a center portion with Vickers hardness of 550 to 700 HV in the cross section; and a high hardness layer with greater hardness than the center portion by 50 to 500 HV from a surface to a depth of 0.05 to 0.3 mm. |
地址 |
Yokohama JP |