摘要 |
<p>The present invention relates to a high strength hot rolled steel plate having excellent impact toughness and a method of manufacturing the same. An embodiment of the present invention provides a hot rolled steel plate including 0.03-0.1% by weight of C, 0.01-0.2% of Si, 0.8-2.0% of Mn, 0.03-0.1% of Al, 0.005-0.3% of Ni, 0.005-0.3% of Cr, 0.005-0.05% of P, 0.001-0.05% of S, 0.015-0.16% of Ti, 0.005-0.2% of Mo, 0.001-0.035% of N, and a remaining content of Fe, and inevitably-contained impurities, satisfying the condition of following equation 1, a yield rate of 0.85-0.95, tensile strength×an elongation percentage (TS×T-EI) of at least 22,500 M Pa%, and impact toughness of at least 20J. Equation 1, 563 - 428[C] - 24[Si] - 37.6[Mn] + 130[Al] - 154[Ni] + 1.2[Cr] - 256[Mo] + 199[Ti] + 9648[B] + 228[N] + 0.065TiN* - 0.223FDT - 0.368CT >= 30 where the unit of [C], [Si], [Mn], [Al], [Ni], [Cr], [Mo], [Ti], [B], and [N] is % by weight, the TiN* represents (0.2 + [Ti] - 0.001[Mo] - 3.985[C]) / (0.018 + [N] - 0.519[Al] - 1.296[B]), The FDT represents hot finish rolling temperature, and the CT represents winding temperature.</p> |