| 摘要 |
PURPOSE:To produce stably a titled steel sheet by subjecting a low carbon billet contg. Si, Mn, P, S, sol.Al, N to hot-rolling then to cold rolling under specific conditions followed by box annealing at the recrystallization temp. or above. CONSTITUTION:The billet contg. <=0.1% C, <=1.0% Si, <=1.2% Mn, 0.03-0.12% P, <=0.015% S, 1.93XN% -0.025% sol.Al, 0.0040-0.0100% N and consisting of the balance Fe with unavoidable impurities is produced by ingot making-blooming or continuous casting. Such billet is heated to 950-1,200 deg.C in a hot rolling stage, is finish rolled at the Ar3 point or above and is coiled at <=600 deg.C. The hot-rolled coil is cold rolled after descaling and is then subjected to heating at <=100 deg.C/h average heating rate and box annealing at the recrystallization temp. or above and <=800 deg.C. |
