Patent ID: 8168011
Filing Date: 2012-05-01
Classification: C21D,C22C

Abstract:
1. A steel wire rod comprising in mass %, C: 0.70 to 1.10%, Si: 0.1 to 1.5%, Mn: 0.1 to 1.0% Al: 0.01% or less, Ti: 0.01% or less, N: 10 to 60 mass ppm, B: not less than (0.77×N (mass ppm)−17.4) mass ppm or 3 mass ppm, whichever is greater, and not greater than 52 mass ppm, and having a balance of Fe and unavoidable impurities; and a post-patenting pearlite structure of an area ratio of 97% or greater and a balance of non-pearlite structures including bainite, degenerate-pearlite and pro-eutectoid ferrite, wherein the wire rod has an average pearlite block size of 10 μm or more, whose fracture reduction of area RA satisfies Expressions (1), (2) and (3) below and whose tensile strength TS satisfies Expression (4) below: where RAmin=a−b×pearlite block size (μm),