High-strength steel wire excelling in resistance to strain aging embrittlement and longitudinal cracking, and method for production thereof

摘要

Disclosed herein is a high-strength high-carbon steel wire which, owing to its high strength as well as good ductility, is excellent in resistance to strain aging embrittlement and longitudinal cracking.;The steel wire is characterized by having a chemical composition (in mass%) including C : 0.75-1.20%, Si : 0.1-1.5%, Mn : 0.3-1.2%, P : no more than 0.02%, S : no more than 0.02%, Al : no more than 0.005%, and N : no more than 0.008%, with the remainder being Fe and inevitable impurities. The steel wire is further characterized by having worked pearlite structure containing lamellar cementite in amorphous form, a diameter (D) ranging from 0.15 to 0.4 mm, a metal lubricating film as the surface layer whose main phase is composed of at least one of Cu, Ni, and Zn or an alloy thereof, and tensile strength no lower than (3500 × D^-0.145) MPa and no higher than (3500 × D^-0.145 + 87 × [C]^-5) MPa, where [C] denotes C content in %.