发明名称 |
COIL SPRING, AND METHOD FOR MANUFACTURING SAME |
摘要 |
To provide a coil spring having excellent fatigue resistance. Disclosed is a coil spring made of steel, including (in % by mass, the same shall apply for a chemical composition): C: 0.40 to 0.70%; Si: 1.50 to 3.50%; Mn: 0.30 to 1.50%; Cr: 0.10 to 1.50%; V: 0.50 to 1.00%, and Al: 0.01% or less (excluding 0%), with the balance being iron and inevitable impurities, wherein an average crystal grain size number of prior austenite crystals in a depth of 0.3 mm from a surface is 11.0 or more, while a difference in grain size number between the respective prior austenite crystals is in a range of less than 3 from a grain size number observed at the maximum frequency, and wherein a carburized layer is provided in a depth of 0.30 to 1.00 mm from the surface, while an average Vickers hardness is 600 or higher at a position in a depth of (1/4) × diameter in the depth direction from the surface. |
申请公布号 |
EP3020841(A4) |
申请公布日期 |
2017.03.29 |
申请号 |
EP20140823237 |
申请日期 |
2014.07.08 |
申请人 |
NHK Spring Co., Ltd.;Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.);Shinko Wire Co., Ltd. |
发明人 |
YAMAMOTO, Fumio;TSURUGAI, Kengo;YOSHIHARA, Nao;MASUMOTO, Kei;OURA, Hiroshi;JINBO, Tetsuo;MAEHATA, Toshio;YAMAMOTO, Yoshiharu |
分类号 |
C22C38/00;C21D1/06;C21D1/773;C21D6/00;C21D9/02;C22C38/04;C22C38/06;C22C38/24;C22C38/26;C22C38/34;C22C38/46;C22C38/48;C23C8/22 |
主分类号 |
C22C38/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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