| 摘要 |
<p>The present invention relates to a high-strength hot-rolled steel sheet having excellent formability and fatigue resistance and to a manufacturing method thereof. More specifically, the said invention relates to a high-strength hot-rolled steel sheet having excellent formability and fatigue resistance and to a manufacturing method thereof, wherein the sheared edge bending ratio and fatigue resistance of a shear edge can be improved by adjusting a content of components constituting molten steel to manufacture a hot-rolled steel sheet. According to an embodiment of the present invention, the high-strength hot-rolled steel sheet having excellent formability and fatigue resistance comprises: 0.03-0.1 wt% of C; 0.05-0.2 wt% of Si; 0.8-2 wt% of Mn; 0.005-0.05 wt% of P; 0.001-0.005 wt% of S; 0.03-0.1 wt% of Al; 0.005-0.5 wt% of Cr; at least two components selected from a group consisting of Ti, Nb, Mo and V wherein the sum of the components account for 0.1-0.5 wt%; and the remainder consisting of Fe and other inevitable impurities, wherein formula 1 is satisfied. [Ti*]/([Ti**]+[Nb*]+[Mo*]+[V*])>=0.95 .................................[Formula 1] wherein [Ti*]= 0.292[Ti], [Ti**]= 0.25([Ti]-0.292[Ti]), [Nb*]= 0.129[Nb], [Mo*] = 0.125[Nb], [V*] = 0.274[V], and Ti, Nb, Mo and V represent the contents (wt%) of the components respectively.</p> |
