590MPa-grade high-formability hot-dip galvanized dual-phase steel plate and preparation method thereof

The invention relates to the field of automobile steel manufacturing, in particular to a 590MPa-grade high-formability hot-dip galvanized dual-phase steel plate and a preparation method thereof. Comprising the following components in percentage by weight: 0.05%-0.09% of C, 0.5%-0.9% of Si, 1.0%-1.8% of Mn, less than or equal to 0.02% of P, less than or equal to 0.01% of S and 0.02%-0.06% of Al. The alloy comprises the following components in percentage by weight: 0.3-0.9% of Cr, and the balance of Fe and inevitable impurities, and w is the percentage by weight. Compared with conventional DP590, under the condition that the yield strength and the tensile strength are basically kept consistent, the ductility (A80 longitudinal direction) can be improved by 20% or above, the n10-20/Ag value can be improved by 22% or above, the hole expansion rate can be improved by 28% or above, and the stamping ductility and the flanging formability of the material are synchronously improved. The conventional steel-making, hot-r