| 摘要 |
PURPOSE:To inexpensively manufacture a cold rolled steel plate with high tensile strength by hot rolling a steel contg. specified components under specified temp. conditions followed by coiling at a specified temp., pickling, cold rolling and strain relief annealing under specified conditions. CONSTITUTION:A steel consisting of, by wt., 0.02-0.30% C, <=1.2% Si, 0.10- 2.50% Mn, 0.01-0.20% sol. Al and the balance Fe and inevitable impurities is hot rolled so as to adjust the final finish temp. to 600-900 deg.C. The hot rolled plate is coiled at 50-400 deg.C to solubilize carbon in the plate or convert it into fine carbide, thereby inhibiting the formation of voids in the next cold rolling process. The coil is then pickled under ordinary conditions, cold rolled at >=20% reduction ratio, and subjected to strain relief annealing at >=300 deg.C to obtain a cold rolled steel plate with improved elongation in the T direction and >= about 50kg/mm.<2> high strength. |
