| 摘要 |
Disclosed are a high strength and cold rolled steel plate with excellent surface quality of thin slabs, weldability, and bendability; 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; 1.5-2.3 wt% of Mn; 0.001-0.06 wt% of P; 0.001-0.02 wt% of S; 0.001-0.1 wt% of Al; 0.0001-0.15 wt% of Cu; 0.0001-0.005 wt% of B; 0.001-0.013 wt% of N; 0.001-0.7 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 the C, Si, Mn, P, and Cr satisfies the relationship formula 1, where the relationship formula 1 is represented by 0.001<=0.05-(wt%C)+0.01(wt%Si)+0.01(wt%Mn)-0.06(wt%P)+0.01(wt%Cr)<=0.025. Content of the C, Si, Mn, P and S satisfies the relationship formula 2, where the relationship formula 2 is represented by 0.1<={(wt%C)+(wt%Si)/30+(wt%Mn)/20+(wt%P)×2+(Wt%S)×4}<=0.5. In the relationship formulas, contents inside the parentheses represent wt% value for each corresponding element. |
