PURPOSE: To improve the press formability by continuously casting a steel contg. specified amounts of C, Mn, sol. Al, N and ≥1 kind among Ti, Nb and Zr and having specified relation between Ti equiv. and C equiv., continuously hot rolling the resulting thin billet, and subjecting it to cold rolling and recrystallization annealing.

CONSTITUTION: The composition of a steel is composed of, by weight, 0.001W 0.015% C, 0.01W1.2% Mn, <0.1% sol. Al, 0.0005W0.006% N, ≥1 kind among <0.2% each of Ti, Nb and Zr, and the balance Fe with inevitable impurities. The relation betwen the Ti equiv. represented by equation I and the C equiv. represented by equation II is allowed to satisfy equation III. The steel is continuously cast into a thin billet, and the billet is continuously hot rolled as it is or under auxiliary heating. It is descaled, cold rolled at ≥50% draft, and subjected to recrystallization annealing at ≥600°C.