Abstract: A process of producing a cold rolled killed steel sheet with good cold formabilities particularly by continuous-annealing, and more particularly to a process of producing cold rolled steel sheet and strip having particularly enhanced deep drawability by controlling the chemical composition and compositional proportions of the killed steel as well as the high temperature coiling after a hot rolling operation.

Abstract: A method for producing a cold rolled steel sheet having high strength and stretchability which comprises hot rolling a steel containing 0.03 to 0.30% C, less than 0.7% Si, 0.6 to 2.5% Mn, 0.01 to 0.20% sol.Al, not more than 0.015% O with the balance being Fe and unavoidable impurities, cold rolling with a reduction not less than 30%, heating with an average heating rate not less than 3.degree.C/sec. annealing in a temperature range from 650.degree.C to A.sub.3 transformation point for 1 to 15 minutes, and cooling with an average cooling rate of 0.5.degree. to 30.degree.C/sec. down to 500.degree.C.

Abstract: A method for producing a high-strength cold rolled steel sheet or strip is disclosed. Steel comprising0.05 to 0.15% of C;0.02 to 0.30% of Si;0.10 to 1.5% of Mn;0.02 to 0.07% of Al; andA total of 0.02 to 0.15% of at least one ofNb, V, Ti and Zr;With the remainder being iron and unavoidable impurities,Is hot rolled whereafter the hot rolled steel sheet or strip is coiled at a temperature of not more than 750.degree.C. The coiled sheet or strip is then cold rolled whereafter the cold rolled steel sheet or strip is subjected to annealing at a temperature between 670.degree.C and 900.degree.C for 20 seconds to 10 minutes.