HIGH-HEAT RESISTANCE COLD-ROLLED STEEL SHEET WITH EXCELLENT WORKABILITY AND A MANUFACTURING METHOD THEREOF WHICH FORMS FINE Nb-BASED CARBIDE PRECIPITATES BY OPTIMIZING STEEL COMPONENTS AND PROCESSING CONDITIONS

摘要

PURPOSE: A high-heat resistance cold-rolled steel sheet and a manufacturing method thereof are provided to obtain excellent workability and heat resistance at the same time by controlling the volume fraction of an acicular ferrite structure.;CONSTITUTION: A high-heat resistance cold-rolled steel sheet comprises 0.002-0.005wt.% of C, 0.05-0.10wt.% of Nb, 0.07-0.55wt.% of Mn, 0.01-0.10wt.% of Al, 0.003-0.020wt.% of P, 0.002-0.006wt.% of N, 0.015wt.% or less of S, and the remaining amount of Fe and inevitable impurities, where the atomic ratio of Nb to C is 2.5-4.5. The cold-rolled steel sheet comprises equiaxed-phase ferrite and acicular ferrite structures.;COPYRIGHT KIPO 2013