HIGH-STRENGTH SPRING STEEL WIRE, HIGH-STRENGTH SPRINGS AND PROCESSES FOR PRODUCTION OF BOTH

摘要

The present invention provides high strength spring and high strength spring steel wire superior in corrosion fatigue characteristics and methods of production of the same, that is, a high strength spring steel wire and high strength spring containing, by mass%, C: 0.35 to 0.50%, Si: 1.00 to 3.00%, and Mn: 0.10 to 2.00%, restricting P to 0.015% or less and S to 0.015% or less, having a balance of Fe and unavoidable impurities, and, when raising the temperature in the range from 50°C to 600°C by 0.25°C/s and measuring the differential scanning calories, having the only peak of the exothermic reaction present at 450°C or more. A method of production of high strength spring characterized by tempering under conditions where the tempering temperature T[K], tempering time t[s], and content Si% [mass%] of Si satisfy the following: 16000‰¤(T-40×[Si%])×(31.7+logt)‰¤23000.