| 摘要 |
<p>PURPOSE: A high-tension steel sheet and a manufacturing method thereof are provided to form modified structure containing acicular ferrites and bainites of which mean crystal grain sizes are less than 10 micron meters. CONSTITUTION: A high-tension steel sheet manufacturing method is a follows. A slab sheet is composed of 0.05-0.10wt.% of C, 0.05-0.50wt.% of Si, 1.0-1.6wt.% of Mn, less than 0.015wt.% of P, less than 0.010wt.% of S, 0.01-0.05wt.% of Al, 0.010-0.020wt.% of Ti, 0.002-0.006wt.% of N, 0.005-0.03wt.% of Nb, and the rest of Fe and inevitable impurities. The slab sheet is reheated at 1,050-1,200°C. The reheated slab sheet is firstly rolled in a recrystallization zone. The firstly rolled slab sheet is secondarily rolled in a non-recrystallization zone by using multiple rolling passes. The secondarily rolled slab sheet is cooled to 450-600°C.</p> |
