| 摘要 |
PROBLEM TO BE SOLVED: To provide spring steel excellent in fatigue strength in corrosive and non-corrosive environments and resistance to permanent set after repeated use. SOLUTION: The spring steel comprises, by mass%, 0.45-0.70% C, 1.65-2.50% Si, 0.20-0.75% Mn, 0.60-2% Cr, 0.15-1% Ni, from trace amount to 1% Mo, 0.003-0.8% V, 0.10-1% Cu, 0.020-0.2% Ti, from trace amount to 0.2% Nb, 0.002-0.050% Al, from trace amount to 0.015% P, from trace amount to 0.015% S, from trace amount to 0.0020% O, 0.0020-0.0110% N and the balance substantially being Fe and unavoidable impurities. Moreover, Ceq, which is calculated by the formula: Ceq.=[C]+0.12[Si]+0.17[Mn]-0.1[Ni]+0.13[Cr]-0.24[V], is 0.80-1.00%, and Rockwell hardness HRC of the spring steel after quenching and tempering is 55 or more. COPYRIGHT: (C)2007,JPO&INPIT
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