| 摘要 |
<p>PURPOSE: A high-strength hot-rolled steel plate with excellent hot ductility is provided to enable the reduction ratio of a sectional area to be over 40% by controlling the contents of Nb and V and stably ensure the rolling performance in a finishing rolling step. CONSTITUTION: A high-strength hot-rolled steel plate with excellent hot ductility comprises carbon of 0.04~0.06 weight%, niobium of 0.01~0.05 weight%, and vanadium of 0.01~0.1 weight%. The steel plate has tensile strength of over 540MPa. The hot-rolled steel plate further comprises titanium of 0.005~0.03 weight%. Alternatively, the steel plate comprises carbon of 0.04~0.06 weight%, silicon of 0.1~0.3 weight%, manganese of 0.8~1.8 weight%, phosphorus of 0.015 or less weight%, sulfur of 0.003 or less weight%, niobium of 0.01~0.05 weight%, and vanadium of 0.01~0.1 weight%.</p> |
