HIGH-STRENGTH STRUCTURAL STEEL AND A MANUFACTURING METHOD THEREOF USING A SMALL AMOUNT OF ADDITIONAL ALLOY ELEMENTS INCLUDING ALUMINUM, VANADIUM, AND NITROGEN

摘要

PURPOSE: High-strength structural steel and a manufacturing method thereof using a small amount of additional alloy elements are provided to secure a yield strength of 450MPa or more and an impact value of 100J or more by controlling the content and cooling conditions of aluminum, vanadium, and nitrogen, excluding controlled rolling.;CONSTITUTION: High-strength structural steel comprises carbon of 0.14-0.16 weight%, silicon of 0.25-0.35 weight%, manganese of 1.25-1.35 weight%, phosphorus of 0.03 weight% or less, sulfur of 0.015 weight% or less, nickel of 0.1-0.15 weight%, chrome of 0.07-0.15 weight%, copper of 0.15-0.2 weight%, vanadium of 0.04-0.06 weight%, aluminum of 0.04-0.06 weight%, nitrogen of 0.008-0.012 weight%, and iron and inevitable impurities of the remaining amount. A manufacturing method for the high-strength structural steel comprises the steps of: reheating steel slab(S110), rolling the steel(S120), and cooling the steel(S130).;COPYRIGHT KIPO 2012