Fig. 1. Microstructures of 0.1C-5Mn medium Mn steel. (a) Under scanning electron microscope; (b) under transmission electron microscopy

Fig. 2. Schematic of laser welding

Fig. 3. Size of tensile specimen

Fig. 4. Metallographic images of joints. (a) HH; (b) LH

Fig. 5. Microstructure morphologies of HAZs in HH joint. (a) FZ; (b) CGHAZ; (c) FGHAZ; (d) ICHAZ; (e) SCHAZ

Fig. 6. Microstructure morphologies of HAZs in LH joints. (a) FZ; (b) FL; (c) FGHAZ; (d) ICHAZ; (e) SCHAZ

Fig. 7. Morphologies of FZs in joints after corrosion. (a) HH, SEM; (b) LH, SEM; (c) HH, TEM; (d) LH, TEM

Fig. 8. Microhardness distributions of joints. (a) HH; (b) LH

Fig. 9. Tensile test results of joints and base materials. (a) Stress-strain curves; (b) local magnification of stress-strain curves; (c) tensile samples

Fig. 10. Morphologies. (a) Base material and joints; (b) fractures in base material; (c) fracture in LH joint; (d) fracture in HH joint

Fig. 11. Erichsen value of tailor-welded blank

Fig. 12. Morphologies of samples after tailor-welded blank Erichsen test