| 摘要 |
<p>The present invention relates to a high-strength structural steel material for hot forming having a low loss of impact toughness and strength even after hot forming. By manufacturing the high-strength structural steel material in accordance to the manufacturing method of the present invention, the high-strength structural steel material has a tensile strength of 700 Mpa or higher even after hot rolling and cooling, and has a yield strength of 460 Mpa or higher; has a tensile strength of 600 Mpa or higher; and an impact absorbing energy of 100 J or higher at -5°C after hot forming at 800°C for 30 minutes may be provided. The high-strength structural steel material comprises: 0.10-0.20 wt% of C, 1.2-2.5 wt% of Mn, 0.2-0.8 wt% of Si, 0.005-0.10 wt% of Nb, 0.01-1.0 wt% of Mo, 0.05-1.0 wt% of Cr, 0.005-0.1 wt% of Ti, 0.005-0.5 wt% of Al, 70-150 ppm of N, 60 ppm or less of Ca (exclusive of 0 ppm), 0.02 wt% or less of P, 0.01 wt% or less of S, at least one selected from a group composed of 0.010-1.0 wt% of Cu, 0.01-2.0 wt% of Ni, 0.005-0.3 wt% of V, and 0.005-0.2 wt% of W, and the remainder consisting of Fe and inevitable impurities.</p> |
