| 摘要 |
PURPOSE: To produce a spring steel having medium strength and securing corrosion resistance by a simplified process and accordingly at a low cost. CONSTITUTION: This spring steel has an alloy composition which consists of 0.3-0.6% C, 1.0-2.0% Si, 0.1-<0.5% Mn, 0.4-1.0% Cr, 0.1-0.3% V, >0.5-1.2% Ni, 0.1-0.3% Cu, and the balance Fe and in which the contents of S and O are regulated to <=0.005% and <=0.0015%, respectively. It is preferable that 0.001-0.005% Ca is incorporated. In order to attain the fatigue limit under corrosive environment, distinctly higher than that of conventional steel (SUP7), the contents of S, Ni, Cr, Cu, and V are further regulated to specific values selected in the above ranges, respectively. Moreover, in order to obtain low as-normalized hardness capable of obviating the necessity of annealing prior to working, the contents of C, Si, Mn, Cr, and Ni are further regulated to specific values selected in the above ranges, respectively.
|
