Spring steel of high strength and high toughness, as well as production method therefor

摘要

The disclosed spring steel for automotive suspension spring provides a combination of excellent mechanical properties, high strength and toughness, and deformation resistance. The spring steel comprises, in weight percent, 0.5 to 0.7% carbon, 1.0 to 3.0% silicon, 0.3 to 1.5% manganese, 0.3 to 1.0% chromium, 0.05 to 0.3% vanadium, 0.5 to 3% nickel, phosphorus and sulfur each not exceeding 0.02%, and the balance of iron and inevitable impurities. The spring steel is produced by the processes of heating for austenization of the spring steel having the same chemical composition as mentioned above as a starting material at 830 to 870deg.C, and then tempering of the heated spring steel at 320 to 420deg.C.