DUAL PHASE STEEL HAVING SUPERIOR DEEP DRAWING, AND METHOD FOR MANUFACTURING OF IT

摘要

Composite steel having a superior deep drawing characteristic is provided to realize a high r value while maintaining high strength of the composite steel by improving the deep drawing property. Composite steel having a superior deep drawing function comprises 0.01 to 0.03 weight percent of C, 0.3 weight percent or less of Si, 1.0 to 2.0 weight percent of Mn, 0.01 to 0.06 weight percent of P, 0.015 weight percent or less of S, 0.2 to 0.8 weight percent of soluble Al, 0.003 weight percent or less of N, 0.2 to 1.0 weight percent of Mo, 0.5 weight percent or less of Cr, 0.0005 to 0.0015 weight percent of B, Fe and inevitable impurities. The composite steel has a dual phase structure of martensite and ferrite.