Fig. 1. Schematics of laser-MIG hybrid welding. (a) Schematic of welding; (b) schematic of groove

Fig. 2. Sampling location and specimen dimensions for tensile test. (a) Sampling location; (b) specimen dimensions

Fig. 3. Sampling location and specimen dimensions for impact test. (a) Sampling location; (b) specimen dimensions

Fig. 4. Influence of oscillating laser on macroscopic appearance of joint. (a) Without laser beam oscillation; (b) with laser beam circular oscillation

Fig. 5. Influence of oscillating laser on joint microstructure. （a） Without laser beam oscillation； （b） with laser beam circular oscillation

Fig. 6. Influence of oscillating laser on joint grain size. (a) Without laser beam oscillation; (b) with laser beam circular oscillation

Fig. 7. Influence of oscillating laser on Schmid factor of weld. (a) Schmid factor distribution plot and (b) histogram without laser beam oscillation; (c) Schmid factor distribution plot and (d) histogram with laser beam circular oscillation

Fig. 8. Influence of oscillating laser on weld grain boundary. (a) Distribution of grain boundary and (b) distribution of grain boundary orientation difference without laser beam oscillation; (c) distribution of grain boundary and (d) distribution of grain boundary orientation difference with laser beam circular oscillation

Fig. 9. Influence of oscillating laser on joint hardness distribution

Fig. 10. Influence of oscillating laser on joint tensile property. (a) Fracture position of specimen without laser beam oscillation; (b) fracture position of specimen with laser beam oscillation; (c) tensile strength

Fig. 11. Influence of oscillating laser on joint impact property

Fig. 12. Microscopic morphologies of impact fractures. (a) Base metal; (b) without laser beam oscillation; (c) with laser beam circular oscillation

Fig. 13. Laser energy distribution and grain refinement mechanism. (a)‒(c) Laser energy distribution and molten pool flow behavior without laser beam oscillation; (d)‒(f) laser energy distribution and molten pool flow behavior with laser beam circular oscillation