Abstract: Through statistical analysis of chemical composition and mechanical properties of hot rolled strip Q215B, the regression model was established and the chemical composition was optimized. Practice production proved that the regression models was feasible to predict the performance, it reduced manganese alloy consumption and created the economic benefits of 12.22 RMB for per ton steel by the strength mode changed from carbon to manganese, realizes the low cost of steelmaking, the qualified rate of transverse cold bending increased nearly 30% with the new pretreatment process. Finally the low cost of steelmaking and the improvement of comprehensive properties were achieved.

Key words: properties prediction, optimization of chemical composition, regression model, low cost