| 摘要 |
Provided is a spring steel that ultimately forms a high strength spring by maximizing a temper softening resistance effect achieved by alloying elements while suppressing the generation of a SiO2 hard inclusion or the occurrence of decarbonization, which cause a deterioration in the fatigue characteristics of a spring. This spring steel is characterized by containing, in terms of mass %, 0.50 to 0.70% of C, 1.00 to 5.00% of Si, 0.30 to 2.00% of Mn, 0.0002 to 0.0500% of P, 0.0002 to 0.0500% of S, 0.10 to 3.50% of Cr, 0.0005 to 0.0500% of Al and 0.0020 to 0.0100% of N, with the remainder comprising Fe and unavoidable impurities, wherein the value of H, as defined by formula (a) is 160 or higher and the value of C, as defined by formula (b), is 3.25 or lower. H = 33.6[C] + 10.0[Si] + 5.95[Mn] + 11.1[Cr] + 90.0···(a) C = [Si]/[Mn]···(b). |
