STEEL FOR HIGH STRENGTH SPRING HAVING SUPERIOR FRESH PROCESSING AND METHOD FOR MANUFACTURING WIRE ROD AND STEEL WIRE USING THE STEEL

摘要

PURPOSE: A steel for high strength spring having fresh processing and a method for manufacturing wire rod and steel wire using the steel are provided to economically manufacture high strength cold formed spring steel wire having a tensile strength by manufacturing wire rod having high strength ferrite + pearlite microstructure in a Stelmor equipment. CONSTITUTION: A steel for high strength spring having superior fresh processing consists of 0.40 to 0.65 wt% of carbon, 1.2 to 1.8 wt% of silicon, 0.3 to 0.8 wt% of manganese, 0.3 to 0.6 wt% of chromium, 0.05 to 0.20 wt% of molybdenum, 0.05 to 0.20 wt% of tungsten, 30 to 120 ppm of nitrogen, 0.02 wt% or less of phosphorous and sulfur, and balance of Fe and inevitable impurities.