LOW DENSITY GRAVITY AND HIGH STRENGTH HOT ROLLED STEEL, COLD ROLLED STEEL AND GALVANIZED STEEL WITH EXCELLENT RIDGING RESISTIBILITY AND A MANUFACTURING METHOD THEREOF

摘要

PURPOSE: A low density gravity and high strength hot rolled steel, cold rolled steel and galvanized steel with excellent ridging resistibility and a manufacturing method thereof are provided to control alloy component included in the steel material and to make a steel sheet have tensile strength more than 600MPa.;CONSTITUTION: A low density gravity and high strength hot rolled steel with excellent ridging resistibility comprises 0.2~0.8% C, 2~10% Mn, 3~15% Al, 0.01% or less N and 0.015% or less S. Mn and Al is Mn/Al:0.4~1.00. The retained austenite is included within organization over 1%.;COPYRIGHT KIPO 2010