Effect of the main alloy composition of cold rolled hot dip galvanized dual-phase steel on its mechanical properties has been studied systematically.Based upon the research results,a mathematical expression related to mechanical properties and compositions of the main alloys has been established.It helped realize the modeling of the composition design of CR hot-dip galvanized DP steel,and provided a favorable route to optimize the composition design,to get rid of the blindness of the composition design,to r...