HIGH STRENGTH AND HIGH TOUGHNESS STEEL WIRE ROD FOR A SPRING AND A MANUFACTURING METHOD THEREOF, AND A SPRING MANUFACTURING METHOD

摘要

PURPOSE: A high strength and high toughness steel wire rod for a spring and a manufacturing method thereof, and a spring manufacturing method are provided to prevent the reduction of area decreasing rate of a steel wire rod and improve the strength of the steel wire rod through cold-rolling of the steel wire rod at the room temperature.;CONSTITUTION: A high strength and high toughness steel wire rod for a spring comprises C 0.4~0.7 weight%, Si 1.5~3.5 weight%, Mn 0.3~1.0 weight%, Cr 0.01~1.5 weight%, Mo 0.01~1.0 weight%, Ni 0.01~1.0 weight%, Cu 0.01~1.0 weight%, B 0.005~0.02 weight%, O 0.0015 weight% or less, Al 0.1 weight% or less, P 0.02 weight% or less, S 0.02 weight% or less, and the rest Fe and other inevitable impurities.;COPYRIGHT KIPO 2010