PURPOSE: To obtain a high tensile hot rolled steel strip of superior low temp. toughness by subjecting a continuously cast slag of a specific compsn. to rough rolling by avoiding long-time heating in a low temp. region then to finish rolling at low temps. and high drafts and specifying the cooling, coiling and tempering conditions for the steel strip.

CONSTITUTION: The steel slab contg., by wt%, ≤0.15 C, ≤0.70 Si, 0.50W2.50 Mn, ≤0.025 P, ≤0.005S, 0.01W0.15 Nb, ≤0.070 Al, and if necessary, ≥1 kind among 0.01W0.15 V, 0.005W0.150 Ti, 0.005W0.150 Zr, 0.05W0.50 Mo, 0.10W1.00 Cu, 0.10W 4.00 Ni, 0.10W1.00 Cr, ≤0.020 rare earth elements, and ≤0.010 Ca and the balance substantially Fe is subjected to controlled rolling from 300mm up to 3 times thickness of the product. Rough rolling of such material is begun as it is or after heat insulation in 20min or when the surface temp. attains 1,000W800°C after heating. After the end thereof, finish rolling is begun at 950W750°C within 60sec to 60% draft. The rolling is finished at the Ar3 transformation point W650°C. The steel strip is coiled at ≤MS point +50°C, and after cooling down to the coiling MF point, the strip is tempered at the Ac1 transformation point or below.