| 摘要 |
PURPOSE:To produce a hot-rolled steel plate of superior ductility and workability by hot rolling an extra low carbon steel then subjecting the same to heat treatment under specific conditions. CONSTITUTION:A slab of an extra low carbon steel contg. <0.02% C, <0.05% Si, <0.25% Mn, and <0.015% S, or further contg. one or more kinds of <0.10% sol. Al, <0.15% rare earth elements, and <0.15% Zr is hot-rolled to produce a steel plate of about 2mm. thickness. This steel plate is soaked for 0.5-30min at temperatures above the AC3 transformation point temperature of this steel in a continuous soaking pit. Next, it is cooled at 3-30 deg.C/sec. cooling rates from the above- mentioned soaking temp. up to 300 deg.C. This steel plate is straightly coiled or coiled after water hardening. The hot-rolled steel plate of superior ductility and workability is obtained. |
