| 摘要 |
PURPOSE:To obtain a titled steel plate of superior workability by cold rolling the steel plate then subjecting the same to box annealing wherein it is hated to prescribed temps. and is then cooled down to the next prescribed temps. and is held at these temp. then subjecting the same to prescribed continuous annealing. CONSTITUTION:Steel contg., by weight, 0.02-0.12% C, 0.5-1.5% Mn, <=0.1% Al, and in some cases, further contg. Si, P, Cr, Mo, Nb, Ti, V, B, etc., and consisting of the balance Fe is cold rolled. Then, after cold rolling of said steel plate it is subjected to the box annealing of heating to an Ac1 transformation point (Ac1 transformation point +100 deg.C) temp. range for a short time, followed by cooling down to (Ac1 transformation point -100 deg.C) Ac1 transformation point temp. range and holding at these temps. for longer than the time (t) determined by the equationI. Thereafter, it is subjected to the continuous annealing of heating for >=1 second in an alpha-gamma region, and setting the average cooling rate down to 650-300 deg.C to the critical cooling rate (CR deg.C/s)-200 deg.C/s range determined by the equationI. |
