METHOD FOR MANUFACTURING HIGH STRENGTH TIN COATING STEEL PLATE HAVING EXCELLENT PROCESSING AND INTERNAL PRESSURE RESISTANCE PROPERTIES OF CONTAINER THROUGH OPTIMIZING AL AND N CONTENTS OF LOW CARBON

摘要

PURPOSE: To manufacture a high strength tin coating steel plate having excellent container processing property and container internal pressure strength of 3.5 kg/cm¬2 or more by optimizing Al and N contents of low carbon steel and over-aging section inlet temperature of cold annealing furnace. CONSTITUTION: The method comprises a step of hot rolling an aluminum-killed steel slab comprising 0.06 to 0.09 wt.% of C, 0.35 to 0.50 wt.% of Mn, 0.010 to 0.25 wt.% of soluble Al, 0.007 to 0.013 wt.% of N and a balance of Fe and other inevitable impurities by an ordinary rolling manner; a step of cold rolling the hot rolled aluminum-killed steel to a reduction ratio of 88.5 to 90%; a step of continuously annealing the cold rolled aluminum-killed steel at a recrystallization temperature or more; a step of maintaining an inlet temperature of over-aging section to the temperature range of 350 to 400 deg.C; and a step of skin pass rolling the continuous annealed aluminum-killed steel under the ordinary conditions.