Abstract: The invention discloses a 780 MPa cold-rolled dual-phase strip steel having a microstructure of fine equiaxed ferrite matrix and martensite islands distributed homogeneously on the ferrite matrix, and comprising the following chemical elements in mass percentage: C: 0.06-0.1%; Si?0.28%; Mn: 1.8-2.3%; Cr: 0.1-0.4%; Mo: not added when Cr?0.3%; Mo=0.3—Cr when Cr<0.3%; Al: 0.015-0.05%; at least one of Nb and Ti elements, wherein Nb+Ti is in the range of 0.02-0.05%; and the balance amounts of Fe and other unavoidable impurities. Correspondingly, the invention also discloses a method for manufacturing the 780 MPa cold-rolled dual-phase strip steel. The 780 MPa cold-rolled dual-phase strip steel has high strength, superior elongation, good phosphating property and small anisotropy in mechanical properties.

Abstract: The invention discloses a 780 MPa cold-rolled duel-phase strip steel having a microstructure of fine equiaxed ferrite matrix and martensite islands distributed homogeneously on the ferrite matrix, and comprising the following chemical elements in mass percentage: C:0.06-0.1%; Si?0.28%; Mn:1.8-2.3%; Cr:0.1-0.4%; Mo: not added when Cr?0.3%; Mo=0.3-Cr when Cr<0.3%; Al: 0.015-0.05%; at least one of Nb and Ti elements, wherein Nb+Ti is in the range of 0.02-0.05%; and the balance amounts of Fe and other unavoidable impurities. Correspondingly, the invention also discloses a method for manufacturing the 780 MPa cold-rolled duel-phase strip steel. The 780 MPa cold-rolled duel-phase strip steel has high strength, superior elongation, good phosphating property and small anisotropy in mechanical properties.