Fig. 1. Microstructures of coating and 22MnB5 steel^[25]. (a) Before hot stamping; (b) after hot stamping

Fig. 2. Schematics of oscillation laser filler wire welding of Al-Si coated 22MmB5 steel. (a) Schematic of welding; (b) schematic of oscillation path^[25]

Fig. 3. Metallographic and tensile sampling locations and tensile sample size. (a) Sampling locations^[26]; (b) size of tensile sample^[25]

Fig. 4. Weld section morphologies under different oscillation frequencies after hot stamping. (a) 0; (b) 140 Hz; (c) 200 Hz; (d) 260 Hz; (e) 320 Hz

Fig. 5. Microstructures of welds under different oscillation frequencies after hot stamping. (a)(b) 0; (c)(d) 140 Hz; (e)(f) 200 Hz; (g)(h) 260 Hz; (i)(j) 320 Hz

Fig. 6. Volume fractions of α-ferrite in welds under different oscillation frequencies after hot stamping

Fig. 7. Mechanical properties of welded joints under different oscillation frequencies after hot stamping. (a) Tensile strength; (b) elongation

Fig. 8. Hardness distributions of LW and OLFW2 welded joints after hot stamping

Fig. 9. Fracture locations of welded joints after hot stamping. (a)(b) LW welded joint; (c)(d) OLFW2 welded joint

Fig. 10. Fracture morphologies of welded joints after hot stamping. (a)-(c) LW welded joint; (d)-(f) OLFW2 welded joint

Fig. 11. Microstructures of welds before hot stamping. (a)(b) LW weld; (c)(d) OLFW2 weld

Fig. 12. Microstructure evolution of laser welding pool calculated by Pandat. (a)(b) LW molten pool; (c)(d) OLFW2 molten pool