摘要 |
A spring steel of medium strength and sufficient corrosion resistance prepared by simple procedures, and therefore, at a low cost, is provided. The spring steel has the alloy composition of: C 0.3-0.6%, Si 1.0-2.0%, Mn 0.1% to less than 0.5%, Cr 0.4-1.0%, V 0.1-0.3%, Ni more than 0.5% to 1.2%, Cu 0.1-0.3% and the balance of Fe, wherein S being at highest 0.005%, and [O], at highest 0.0015%. Addition of Ca 0.001-0.005% is preferable. In order to ensure clearly improved fatigue limit under corrosive environment to the conventional steel, SUP7, specific contents of S, Ni, Cr, Cu and V are chosen in the range set forth above. For the purpose of obtaining such a low hardness after normalizing at which annealing prior to processing is unnecessary contents of C, Si, Mn, Cr and Ni are further chosen in the above ranges.
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