| 摘要 |
<p>PURPOSE: A cold-rolled steel sheet and a manufacturing method thereof are provided to obtain a cold-rolled steel sheet with excellent corrosion resistance by forming Cu-based sulfide on the surface of the steel sheet. CONSTITUTION: A cold-rolled steel sheet comprises C of 0.01-0.10%, Mn of 0.10-0.35%, P of 0.003-0.020%, Al of 0.02-0.08%, Sn of 0.05-0.25%, Cu of 0.1-0.4%, N of 0.002-0.006%, Ti of 0.07-0.15%, S of 0.003-0.010%, and Fe and inevitable impurities of the remaining amount. The atomic ratio of Ti and C, Ti/C, is 0.3-0.8 and the atomic ratio of Cu and S, Cu/S, is 10-25. Ti-based carbide precipitate is formed in the cold-rolled steel sheet.</p> |
