| 摘要 |
<p>Provided are a cold-rolled steel sheet with excellent blanking quality and heat strain resistance, and a manufacturing method therefor. A cold-rolled steel sheet with a Vickers hardness of at least Hv 170 comprising: a composition containing, in mass%, C: 0.01% to 0.08%, Si: 0.01% to 1.0%, Mn: 0.05% to 1.0%, P: not more than 0.03%, S: not more than 0.015%, Al: 0.005% to 0.10%, and N: not more than 0.01%, the remainder being obtained from Fe and unavoidable impurities; and a structure wherein the area ratio of ferrite phases is at least 80%, the total area ratio of hard phases obtained from pearlite phases and/or bainite phases is not more than 20%, the mean particle diameter for the hard phases is 1 µm to 10 µm, and the mean aspect ratio for the hard phases is not more than 10.0.</p> |
