| 摘要 |
<p>According to an embodiment of the present invention, an ultra-high-strength hot-rolled steel sheet having excellent impact properties contains, in wt%, 0.06-0.10% of C, 0.4% or less of Si (excluding 0), 1.3-2.0% of Mn, 0.6% or less of Cr (excluding 0), 0.2% or less of Mo (excluding 0), 0.01-0.04% of Al, 0.0005-0.005% of B, 0.005-0.05% of Ti, 0.01% or less of N (excluding 0), 0.02% or less of P (excluding 0), 0.005% or less of S (excluding 0), and the remainder consisting of Fe and inevitable impurities. According to an embodiment of the present invention, yield strength and tensile strength can be improved by appropriately controlling composition and a compositional range of a steel material, a microstructure, and process conditions.</p> |
