Fig. 1. Schematic of laser remelting

Fig. 2. Thermophysical parameters of HT250 gray cast iron. (a) Specific heat; (b) thermal conductivity

Fig. 3. Finite element mesh model diagram

Fig. 4. Temperature field at different times. (a) 0.3 s; (b) 0.8 s; (c) 1.3 s; (d) 1.8 s

Fig. 5. Temperature field cloud map at 0.9 s. (a) Three-dimensional temperature field; (b) temperature field in X‒Z plane; (c) temperature field in Y‒Z plane; (d) temperature gradient distribution along path pq line

Fig. 6. Temperature profiles of various positions along the depth direction in melted pool

Fig. 7. Temperature field at different laser powers. (a) Thermal circulation curves of the point P; (b) temperature distribution along path pq line at different laser powers

Fig. 8. Comparison of experimental and simulation results. (a) Comparison of melted pool shape between experiment and calculation; (b) depth of melted pool; (c) width of melted pool

Fig. 9. Line of gray cast iron after laser surface remelted by EDS

Fig. 10. Metallograph microstructure of HT250 gray cast iron by laser surface remelting. (a) Cross-sectional morphology of laser remelted layer; (b) microstructure of LRZ; (c) microstructure of HAZ; (d) substrate

Fig. 11. Microhardness profile at the cross section of the laser remelted single-pass channel on the HT250 gray cast iron surface