| 摘要 |
PURPOSE:To obtain a cold rolled steel plate with intrasurface anisotropy and superior workability, especially high deep drawability by hot rolling a billet for a low C cold rolled steel plate while specifying the finish hot rolling inlet temp., the finish rolling thickness ratio and the finishing temp. and by rapidly carrying out forced cooling, coiling at a prescribed temp., cold rolling and recrystallization annealing. CONSTITUTION:A low C steel contg. <=0.08% C and <=0.4% Mn is hot rolled under the conditions of <=T1 deg.C (represented by equationI) finish hot rolling inlet temp., >=13 finish rolling thickness ratio and >=Ar3 point finishing temp. The rolled steel is forced to be cooled as rapidly as possible to T2 deg.C represented by equation II at >=20 deg.C/sec cooling rate, and it is coiled at the desired temp. The hot rolled coil is cold rolled at >=70% cold rolling rate and subjected to recrystallization annealing by continuous annealing or box annealing to obtain the desired cold rolled steel plate with superior workability. |
