| 摘要 |
In a method of producing a high-strength cold-rolled steel sheet excelling in deep drawability, a steel material is used which consists of: a basic composition including 0.01% or less of C, 0.1 to 2.0% of Si, 0.5 to 3.0% of Mn, 0.02 to 0.2% of P, 0.05% or less of S, 0.03 to 0.2% of Al, 0.01% or less of N, 0.001 to 0.2% of Nb, and 0.0001 to 0.008% of B in such a way that the respective contents of C, Nb, Al, N, Si, Mn and P satisfy the following formulae: 5</=Nb/C</=30, 10</=Al/N</=80, and 16</=(3xSi/28+200 xP/31)/(Mn/55)</=40; Fe remnant; and inevitable impurities, the method including the steps of: performing rolling on the steel material with a total reduction of 50% or more and 95% or less while effecting lubrication thereon in a temperature range of not higher than the Ar3 transformation temperature and not lower than 500 DEG C.; performing a hot-rolled sheet recrystallization treatment on the steel material by a coiling or annealing process; performing cold rolling on the steel material with a reduction of 50 to 95%; and then effecting recrystallization annealing on the steel material in a temperature range of 700 DEG to 950 DEG C.
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| 申请人 |
KAWASAKI STEEL CORPORATION |
发明人 |
MATSUOKA, SAIJI;KAWABE, HIDETAKA;YASUHARA, EIKO;SAKATA, KEI;KATO, TOSHIYUKI |
