| 摘要 |
Disclosed are a high strength and cold rolled steel plate with excellent surface quality of thin slabs, and a manufacturing method thereof. According to an embodiment of the present invention, the high strength and cold rolled steel plate comprises: 0.04-0.07 wt% of C; 0.01-0.7 wt% of Si; 1.6-2.3 wt% of Mn; 0.001-0.06 wt% of P; 0.001-0.02 wt% of S; 0.001-0.1wt% of Al; 0.0001-0.15 wt% of Cu; 0.0001-0.005% of B; 0.001-0.013 wt% of N; 0.001-0.4 wt% of Cr; 0.001-0.1 wt% of Ti; 0.001-0.05 wt% of Nb; 0.001-0.1 wt% of V; and the remaining consisting of Fe and inevitable impurities. Content of C, Si, Mn, P, and Cr satisfies the relationship formula 1, where formula 1 is represented by 0.05<=0.8-(wt%C)+0.2(wt%Si)-0.4(wt%Mn)+1.5(wt%P)+0.3(wt%Cr)<=0.2. Content of the Mg, S, and Cu satisfies the relationship formula 2, where formula 2 is represented by 0.01<={(wt%Mn)/(wt%S)}X(wt%Cu)<=80. In the relationship formulas, parentheses individually represents wt% value for each corresponding element. |
