Patent ID: 9212405
Filing Date: 2015-12-15
Classification: B21C,B32B,C21D,C22C

Abstract:
1. A steel wire obtained by performing at least once a wire drawing and a reheating patenting treatment on a wire rod with a composition including: C: 1.12-1.30 mass %; Si: 0.1-1.5 mass %; Mn: 0.1-1.0 mass %; Al: 0-0.1 mass %; Ti: 0-0.1 mass %; P: 0-0.02 mass %; S: 0-0.02 mass %; N: 10-50 ppm; 0: 10-40 ppm; Cr: 0-0.5 mass %; Ni: 0-0.5 mass %; Co: 0-0.5 mass %; V: 0-0.5 mass %; Cu: 0-0.5 mass %; Nb: 0-0.1 mass %; Mo: 0-0.2 mass %; W: 0-0.2 mass %; B: 0-30 ppm; REM: 0-50 ppm; Ca: 0-50 ppm; Mg: 0-50 ppm; Zr: 0-100 ppm; and the balance including Fe and inevitable impurities, in which 97% or more of an area in a cross-section perpendicular to the longitudinal direction of the wire rod is occupied by a pearlite, and 0.5% or less of an area in a central area of the cross-section and 0.5% or less of an area in a first surface layer area in the cross-section are occupied by a pro-eutectoid cementite, wherein: the steel wire has a diameter of 0.1-0.4 mm and a tensile strength of 4200 MPa or higher; and 0.5% or less of an area in a second surface layer area in the cross-section perpendicular to the longitudinal direction of the steel wire is occupied by a pro-eutectoid cementite.