Fig. 1. Thermophysical parameters of 42CrMo steel. (a) Specific heat capacity; (b) thermal conductivity; (c) resistivity; (d) relative permeability

Fig. 2. Schematic diagram of hybrid quenching for 42CrMo steel

Fig. 3. TTT diagram of 42CrMo steel

Fig. 4. CCT diagram of 42CrMo steel^[27]

Fig. 5. Additivity rule

Fig. 6. Heat transfer coefficient of 42CrMo steel. (a) Coolant; (b) air

Fig. 7. Location of feature points

Fig. 8. Temperature history curves of characteristic points. (a) Point M; (b) point N

Fig. 9. Cloud charts of martensite. (a) Single laser quenching; (b) hybrid quenching

Fig. 10. Cross-sectional hardness curves of hardened layer by quenching. (a) Depth direction; (b) horizontal direction

Fig. 11. Cloud charts of temperature field in hybrid quenching process. (a) 3D section view; (b) Y-Z plane

Fig. 12. Temperature history curves of characteristic points for hybrid quenching

Fig. 13. Temperature history curve of point A under different quenching methods

Fig. 14. Microstructure distribution by hybrid quenching at different time

Fig. 15. Cloud diagram of martensite distribution after hybrid quenching

Fig. 16. Cross-sectional morphology of hardened layer by quenching. (a) Single laser quenching; (b) hybrid quenching

Fig. 17. Calculation of martensite proportion

Fig. 18. Microstructure of different positions after hybrid quenching. (a) Hardened layer; (b) heat affected zone; (c) base metal