STEEL FOR BEARING HAVING EXCELLENT THERMAL DEFORMATION RESISTANCE AND METHOD FOR MANUFACTURING THEREOF

摘要

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel wire for bearings widely used in the automobile and machinery industries, such as engines, transmissions and wheels of automobiles, rolling rolls of steel machines, construction machinery, and the like, and more particularly, to steel wire for bearings. By adding silicon, which is a solid solution to the substrate, to minimize the density change in the material during heating and cooling, the steel wire for bearings with excellent heat deformation resistance and minimization of microstructure degradation due to temperature change and its manufacturing method It is about. To this end, the steel wire manufacturing method of the present invention, in weight%, C: 0.9 ~ 1.4%, Si: 1.5 ~ 3.0%, Mn: 0.3 ~ 0.7%, Cr: 0.8 ~ 1.5%, the remaining Fe and other unavoidable Performing a spheroidizing heat treatment of the steel wire including the element at a two-phase temperature of 850 to 900 ° C. for 1 to 3 hours; Cooling the heat treated steel wire at a rate of 0.3 ° C./s or less; Performing a homogenization heat treatment of the cooled steel wire at 830 ° C. for at least 1 hour and quenching at a cooling rate of 5˜10 ° C./s; It includes the step of soaking the quenched steel wire at less than 300 ℃ 1 hour.