Method for producing efficienty a high toughness and high tensile strength steel materials

摘要

A method for producing efficiently a high toughness and high tensile strength steel material which comprises heating a low-carbon or low-carbon low-alloy steel slab and hot rolling the slab, said hot rolling step comprising giving the slab at least one reduction with reduction amount and temperature to be determined by N 2ROOT Ro/H in which Ro is the roll radius(mm) of the rolling mill, N is the roll rotation (rpm) and H is the slab thickness before the reduction.