| 摘要 |
<p>PURPOSE: A method of manufacturing a hot-rolled steel plate is provided to reduce a manufacturing cost by ensuring hole expandability and tensile strength and removing the content of Ti and Mo. CONSTITUTION: A method of manufacturing a hot-rolled steel plate comprises next steps. A steel slab is re-heated(S100). The steel slab is hot rolled(S200). The hot-rolled steel slab is cooled(S300). The cooled steel is wound(S400). The steel slab comprises C of 0.06~0.15 weight%, Si of 0.1~0.3 weight%, Mn of 1.0~2.5 weight%, P of 0.01~0.03 weight%, S of 0.002~0.004 weight%, Al of 0.02~0.04 weight%, Nb of 0.03~0.05 weight%, Cr of 0.2~0.6 weight%, B of 10~25ppm, Ni of 0.2~0.4 weight%, Fe and other inevitable impurities. The re-heated temperature of the steel slab is within 1210~1290°C. The finishing-rolling temperature of the hot-rolled steel slab is within 880~940°C.</p> |
