Fig. 1. Laser-CMT welding diagrams. (a) Experimental site map; (b) diagram of welding

Fig. 2. Schematic of tensile sample size

Fig. 3. Macro morphologies of welded joint under different laser powers. (a1)(a2) 3.0 kW; (b1)(b2) 3.6 kW; (c1)(c2) 4.2 kW;

Fig. 4. Schematic of weld cross-section and statistical results of weld sizes. (a) Schematic of weld cross-section; (b) statistical results of melt width and reinforcement

Fig. 5. Microstructures of weld center under different laser powers. (a) 3.6 kW; (b) 4.2 kW; (c) 4.8 kW

Fig. 6. Microstructures of weld under different laser powers. (a) 3.6 kW; (b) 4.2 kW; (c) 4.8 kW

Fig. 7. Microhardness distributions and weld dilution ratios of full penetration welded joints under different laser powers.（a）Microhardness of joint when laser power is 3.6 kW；（b）microhardness of joint when laser power is 4.2 kW；（c）microhardness of joint when laser power is 4.8 kW；（d）average microhardnesses of WS and HAZ；（e）dilution ratio

Fig. 8. Tensile test results of welded joints. (a) Tensile fracture positions of joints; (b) engineering stress-strain curves of tensile specimens

Fig. 9. SEM morphologies of welded joint tensile fractures.（a）3.6 kW；（b）4.2 kW；（c）4.8 kW