STEEL FOR SPRING, AND METHOD FOR PRODUCING SPRING

摘要

Provided is a steel for a high strength spring, in which excellent decarburization resistance and scale strippability are achieved by optimizing the quantities of Sb and Sn, in addition to C, Si, Mn and Cr, added to a conventional steel for a high strength spring. This steel contains, under prescribed conditions, more than 0.45 mass % but less than 0.65 mass % of C, 0.15-0.70 mass % of Si, 0.10-1.00 mass % of Mn, 0.20-1.50 mass % of Cr, not more than 0.025 mass % of P, not more than 0.025 mass % of S, not more than 0.0015 mass % of O, not less than 0.010 mass % but less than 0.030 mass % of Sb, and 0.010-0.030 mass % of Sn.