| 摘要 |
<p>A high-strength steel plate having excellent yield strength and low temperature toughness, and the manufacturing method thereof are provided to supply a high-strength steel plate having excellent yield strength and low temperature toughness with low expenses by optimizing and controlling component systems and deposits, and controlling hot rolling conditions. A high-strength steel plate having excellent yield strength and low temperature toughness comprises 0.03~0.1 weight percent C, 0.01~0.5 weight percent Si, 1.2~2.0 weight percent Mn, less than 0.02 weight percent S, 0.01~0.1 weight percent Nb, 0.01~0.1 weight percent Ti, less than 0.01 weight percent N, 0.1~0.5 weight percent Mo, 0.1~0.5 weight percent Ni, 0.01~0.1 weight percent V, 0.1~0.5 weight percent Cr, other inevitable impurities and Fe, wherein the Ti, Nb, C and N satisfy the relations as follows: 0.13<= (Ti*/48+Nb*/93)/(C/12) <= 0.25, 0.13<= (Ti*/48+Nb*/93)/(C/12) <= 0.25, 0.24 <= (V/51)/(C*/12) <= 1.6, 0.24 <= (V/51)/(C*/12) <= 1.6, 6<= (Mo/96)/(P/31) <= 30, 6<= (Mo/96)/(P/31) <= 30, and Ti* = Ti - 0.7*(48/14)N, Nb* = Nb-0.7*(93/14)N, C* = C - 0.7*[(Nb-0.7*(93/14)N) + (Ti-0.7*(48/14)N)]. A manufacturing method of a high-strength steel plate comprises the steps of re-heating the high-strength steel plate at 1100~1350°C, going through recystallization and non-recrystallization hot rolling processes within the range of 950~1100°C, going through a hot rolling process for finishing in the reduction ratio of more than 60% at 780~880°C, going through a water cooling process at a velocity of 10~50°C/sec on a run-out table, and winding at 400~600°C.</p> |
