| 摘要 |
<p>PURPOSE: A bake hardenable steel sheet with excellent strain aging resistance and a manufacturing method thereof are provided to achieve proper moldability and dent-resistance and prevent stretcher strain by stabilizing the content of solute nitrogen. CONSTITUTION: A bake hardenable steel sheet with excellent strain aging resistance comprises C 0.003weight%, Si 0.01~0.1 weight%, Mn 0.02~0.2 weight%, P 0.01~0.1 weight%, S 0.02 weight% or less, sol.Al 0.003~0.02 weight%, Cu 0.2 weight% or less, and the rest Fe and inevitable impurities. The contents of Mn, Cu, and S satisfy 0.5*(Mn+Cu)/S:2~20. The steel sheet also comprises one or more among AIN precipitate, CuMnS precipitate, CuS precipitate whose average diameter is 0.1μm or less.</p> |
