Atmospheric corrosion-resistant steel sheet for deep drawing

Claim 1

A PROCESS FOR PRODUCING STEEL SHEET HAVING ATMOSPHERIC CORROSION RESISTANCE AND DEEP DRAWABILITY COMPRISING STEPS OF MAKING AN INGOT CONSISTING ESSENTIALLY OF LESS THAN 0.10% C, LESS THAN 0.08% SI, 0.20-0.60% MN, 0.04-0.12% P, 0.20-0.60% CU, 0.03-0.5% AS AND AT LEAST ONE MEMBER SELECTED FROM THE GROUP CONSISTING OF 0.0005-0.05% TI, 0.01-0.05% AL, 0.005-0.05% ZR AND 0.005-0.05% NB HOT AND COLD ROLLING SAID INGOT TO PRODUCE A COLD ROLLED COIL, ANNEALING SAID COLD ROLLED COIL IN A DECARBURIZING ATMOSPHERE GAS IN AN OPEN COIL ANNEALING APPARATUS AND RECRYSTALLIZING, SOFTENING AND ANNEALING SAID COIL WHILE DECARBURIZING AND DENITRIDING SAME AS TO PRODUCE A NON-AGEING STEEL CONTAINING LESS THAN 0.01% C.