Fig. 1. Microstructure of experimental steel. (a) SEM morphology with low magnification; (b) enlarged microstructure of I area

Fig. 2. Schematic of tailored blank laser welding

Fig. 3. Size of tensile sample

Fig. 4. Size of impact sample

Fig. 5. Macro morphology of welded joints obtained at different heat inputs. (a) 30.0 J/mm; (b) 42.0 J/mm; (c) 48.0 J/mm; (d) 54.0 J/mm

Fig. 6. Microstructures of welded joint obtained at heat input of 42.0 J/mm. (a) Low magnification of WS; (b) high magnification of WS; (c) CGHAZ; (d) FGHAZ

Fig. 7. Microstructure of MGHAZ of welded joint obtained at heat input of 42.0 J/mm. (a) Near MGHAZ; (b) enlarged image of II area

Fig. 8. Microhardness distributions of full-penetration weld joints obtained at different heat inputs. (a) 42.0 J/mm; (b) 48.0 J/mm; (c) 54.0 J/mm

Fig. 9. (a) Images of tensile samples of welded joint after fracture; (b) engineering stress-engineering strain curves of tensile samples

Fig. 10. SEM images of tensile fracture of full-penetration weld joints obtained at different heat inputs and base metal

Fig. 11. Impact fracture morphology of weld seam obtained at different heat input and base metal

Fig. 12. Impact fracture morphology of weld seam obtained at different heat inputs and base metal. (a) 30.0 J/mm; (b) enlarged image of III area; (c) 42.0 J/mm;(d) 48.0 J/mm; (e) 54.0 J/mm; (f) base metal