STEEL WIRE FOR MECHANICAL STRUCTURAL PARTS

摘要

Provided is a steel wire for mechanical structural parts, which can reduce deformation resistance during cold working, can improve cracking resistance, and can exhibit excellent cold workability. The steel wire for mechanical structural parts according to the present invention contains, in % by mass, 0.3 to 0.6% of C, 0.05 to 0.5% of Si, 0.2 to 1.7% of Mn, more than 0% and 0.03% or less of P, 0.001 to 0.05% of S, 0.005 to 0.1% of Al and 0 to 0.015% of N, with the remainder being iron and unavoidable impurities. In the steel wire, the metal structure of the steel is composed of ferrite and cementite, and the ratio of the number of cementite grains present on the ferrite grain boundary is 40% or more relative to the total number of all of cementite grains.