| 摘要 |
PROBLEM TO BE SOLVED: To provide a spring having a high durability in actual use and sagging resistance of the same level as or higher than conventional ones through improvement of the corrosion fatigue resistance. SOLUTION: The spring uses as a material a steel including, by weight, C: 0.35 to 0.55%, Si: 1.60 to 3.00%, Mn: 0.20 to 1.50%, S: 0.010% or less, Ni: 0.40 to 3.00%, Cr: 0.10 to 1.50%, V: 0.05 to 0.50% and Fe balance. The steel is heat treated to have a hardness of 50.5 to 55.0 HRC and shot-peened at a moderate temperature to render a residual stress of -600 MPa or more at a depth of 0.2 mm below the surface. The temperature at which the spring is shot-peened is preferably 100 to 300°C, and the hardness of shot particles for the shot-peening is preferably 450 to 600 Hv. COPYRIGHT: (C)2008,JPO&INPIT
|
