Patent ID: 9005378
Filing Date: 2015-04-14
Classification: C22C

Abstract:
1. A spring steel wire rod comprising: Fe; C in a range of 0.35 to 0.65% mass; Si in a range of 1.4 to 2.2% mass; Mn in a range of 0.10 to 1.0% mass; Cr in a range of 0.1 to 2.0% mass; P not more than 0.025% mass (0% excluded); and S not more than 0.025% mass (0% excluded), wherein an average grain size Dc of a central part of the steel wire rod is more than 20 μm and not more than 80 μm, and an average grain size Ds of a surface layer part of the steel wire rod is not less than 3.0 μm and not more than 16.0 μm.