MANUFACTURING METHOD OF 35 kg/mm¬2 CLASS HIGH TENSILE STRENGTH COLD ROLLED STRIP FOR DEEP DRAWING HAVING SUPERIOR WIRE BENDING PREVENTING CHARACTERISTICS

PURPOSE: Provided is a manufacturing method of 35 kg/mm¬2 class high tensile strength cold rolled strip for deep drawing having superior wire bending preventing characteristics by properly designing steel component system and controlling process variables. CONSTITUTION: The method comprises the steps of heating an ultra-low carbon Al-killed steel slab comprising 0.005 wt.% or less of C, 0.55 to 0.65 wt.% of Mn, 0.015 wt.% or less of S, 0.065 wt.% or less of soluble Al, 0.004 wt.% or less of N, 0.03 to 0.05 wt.% of P, 0.04 to 0.06 wt.% of Ti and a balance of Fe and other inevitable impurities to the temperature range of 1,200 deg.C or more; hot finish rolling the heated steel slab in the temperature range of 900 to 920 deg.C that is directly above the Ar3 temperature; coiling the hot finish rolled strip in the temperature range of 500 to 570 deg.C; cold rolling the coiled strip at a reduction ratio of 60 to 80%; continuous annealing the cold rolled strip in the temperature range of 800 to 850 deg.C; and performing controlled rolling on the continuous annealed strip at a reduction ratio of 0.5 to 1.5%.