Fig. 1. Schematic of welding process. (a) Structure of the heat source; (b) heat source offset

Fig. 2. Schematic of combined heat source

Fig. 3. Schematic of geometry model and mesh generation

Fig. 4. Weld surface morphology. (a) The first welding; (b) the second welding

Fig. 5. SEM analysis results of welded joint. (a) Macroscopic appearance of cross section of welded joint; (b) area A in Fig.5(a); (c) area B in Fig.5(b)

Fig. 6. Comparison of weld morphology. (a) Simulated weld; (b) experimental weld

Fig. 7. Comparison of thermal cycle curves

Fig. 8. Temperature distribution on weldment

Fig. 9. Thermal cycle curves. (a) Thermal cycle curves at position C in Fig.8; (b) temperature distribution along path AB in Fig.8

Fig. 10. Schematic of magnesium alloy/steel joint solidification