Patent ID: 9097306
Filing Date: 2015-08-04
Classification: B21B,B21F,C21D,C22C,F16F,Y10T

Abstract:
1. A steel wire rod for high-strength springs, as a steel wire rod having been hot-rolled and exhibiting excellent wire drawability, the steel wire rod comprising C in a content of 0.4% to 0.8%; Si in a content of 0.5% to 2.5%; Mn in a content of 0.3% to 2.0%; and Cr in a content of 0.4% to 3.0% and further comprising at least one element selected from the group consisting of V in a content of 0.05% to 0.5%, Nb in a content of 0.05% to 0.5%, Ni in a content of 0.1% to 2.0%, and Mo in a content of 0.1% to 0.5%, in mass percent, wherein the steel wire rod further comprises iron and inevitable impurities, the steel wire rod has a structure mainly including pearlite, the steel wire rod has an average Pave and a standard deviation Pσ of pearlite nodule size numbers, and Pave and Pσ respectively satisfy conditions specified by following Expressions (1) and (2):