| 摘要 |
<p>PURPOSE: A bake-hardened steel sheet and a manufacturing method thereof are provided to prevent solute carbon from being bound to coarse MnS with reducing the content of Mn, thereby improving a bake-hardenability according to the increase of the amount of the solute carbon. CONSTITUTION: A bake-hardened steel sheet comprises below 0.003 (excluding zero) wt% of C, 0.01 to 0.2 wt% of Mn, 0.01 to 0.1 wt% of Si, 0.01 to 0.1 wt% of P, below 0.03 (excluding zero) wt% of S, below 0.2 (excluding zero) wt% of Cu, and remnants Fe and other inevitable impurities. Minute CuS precipitates are generated and uniformly distributed in the steel sheet. [Reference numerals] (AA) Comparative steel sheet; (BB) Steel sheet invention</p> |
