| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a manufacturing method for manufacturing a member excelling in shock absorption capability from a cold rolled steel plate. <P>SOLUTION: A steel plate having an organization comprising≥95% of a ferrite phase and obtained by heating, to a temperature≥1,050°C, a steel slab containing, by mass%, 0.005-0.03% of C, 0.05-1.5% of Mn,≤1.5% of Si,≤0.10% of P,≤0.0100% of Si, 0.02-0.8% of Al and≤0.0100% of N, performing finish rolling at a finish rolling outlet side temperature of an Ar<SB POS="POST">3</SB>transformation point to 950°C, rolling up the rolled steel slab at a temperature≤600°C, thereafter performing pickling, performing cold rolling, then performing annealing at a temperature of 700°C to an Ac<SB POS="POST">1</SB>transformation point, successively cooling the rolled steel slab by setting an average cooling rate from 700°C to 250°C to≥15°C/s, and performing temper rolling at a pressure regulation rate of 15-30% is subjected to press molding; and thereafter heat treatment is performed at 140-300°C. <P>COPYRIGHT: (C)2012,JPO&INPIT</p> |
