| 摘要 |
<p>A cold rolled steel sheet capable of enhancing yield ratio and lowering in-plane anisotropy by MnS precipitates in bake-hardening type interstitial free steel and a method for manufacturing the same are provided. A bake-hardening type cold rolled steel sheet with high yield ratio comprises, by weight percent, 0.001 to 0.01% of C, 0.01 to 0.3% of Mn, 0.005 to 0.08% of S, 0.1% or less of Al, 0.004% or less of N, 0.2% or less of P, 0.0001 to 0.002% of B and 0.001 to 0.05% of Nb with the balance being Fe and other inevitable impurities, wherein the Mn and S satisfy (Mn/55)/(S/32)=1 to 30, and Cs(solute carbon) satisfies 5 to 30, wherein Cs=(C-NbÎ12/93)Î10000, and wherein MnS precipitates have an average size of 0.2 mum or less.</p> |
