Abstract: The experiments is designed based on the response surface method, implemented by bead-on-plate welding with laser Nd: YAG-metal active gas welding(MAG) hybrid welding,and using obtained beam appearance data and filtering out significant factors by stepwise regression method to establish multiple nonlinear mathematical regression model. By analysis of variance and regression analysis showed that R2 the regression model are 0.932, 0.915 and 0.910, P>F<0.001, respectively. The weld bead geometry was affected by the laser power, welding current, arc voltage and distance between two sources and these factors’ interaction. The main effect on penetration is the laser power, while the interactive effect is laser power and arc voltage; the main effect on the weld width is welding current and arc voltage, while the interactive effect is welding current and distance between two sources, arc voltage and distance between two sources, laser power and arc voltage; the main effect on the reinforcement is welding current, while the interactive effect is arc voltage and distance between two sources. The results show the simulating results are consistent with the measured results.

Key words: high nitrogen steel, laser-arc hybrid welding, mathematical regression model, response surface method(RSM)