| 摘要 |
<p>Disclosed are a high strength steel plate having excellent thickness-directional material characteristics and a manufacturing method thereof. According to the present invention, the high strength steel plate comprises: a slab reheating step for reheating a slab composed of 0.05-0.15 wt.% of C, 0.1-0.6 wt.% of Si, 1.0-1.8 wt.% of Mn, 0.01-0.06 wt.% of soluble Al, 0.1-0.5 wt.% of Cu, 0.01-0.07 wt.% of Nb, 0.1-0.7 wt.% of Ni, 0.01-0.03 wt.% of Ti, 0.1-2.5 wt.ppm of H, 10-70 wt.ppm of N, and the rest of Fe and inevitable impurities; a hot-rolling step for primarily rolling the slab in an austenite recrystallization section and then secondarily rolling the slab in an austenite non-recrystallization section; and a cooling step for cooling the hot-rolled slab. The slab is reheated at 1000-1150°C for 0.78T+20-0.78T+80 min (T means the thickness of the slab, mm). [Reference numerals] (AA) START;(BB) END;(S110) Reheat a slab;(S120) Primary rolling;(S130) Secondary rolling;(S140) Cooling</p> |
