| 摘要 |
The present invention relates to a low-yield ratio and a high-strength hot-rolled steel sheet with a high impact resistance, and a manufacturing method thereof. According to an embodiment of the present invention, the low-yield ratio and high-strength hot-rolled steel sheet with a high impact resistance comprises: 0.05-0.1 wt% of C, 0.1-1.0 wt% of Si, 1.0-2.0 wt% of Mn, 0.03-0.45 wt% of Al, 0.005-0.55 wt% of Cr, 0.01-0.1 wt% of Mo, 0.01-0.05 wt% of P, 0.0005-0.01 wt% of S, 0.00 -0.01 wt% of N, 0.001-0.15 wt% of the sum of at least one selected from a group consisting of Ti, Nb, and V, and the remainder consisting of Fe and inevitable impurities, has a single or composite carbonitrides of Ti, Nb, and V of which the diameters are 100 nm or more and the number is 1x10^8/cm^2 or less, and has a yield ratio of 0.75 or less. |
