Fig. 1. Schematics of multiple-channel high-speed laser cladding. (a) Schematic of the internal, central, and external of the coating; (b) schematic of areas A1, A2, and A3

Fig. 2. Cloud maps of temperature field distribution at areas A1, A2, and A3. (a) Area A1; (b) area A2; (c) area A3

Fig. 3. Temperature-time curves of cladding layer at areas A1, A2, and A3

Fig. 4. Temperature-time diagram during laser cladding

Fig. 5. Morphology of iron-based TY-1 powder particles

Fig. 6. Schematic of sampling positions of metallographic samples

Fig. 7. Microstructure sampling diagram of single-pass coating

Fig. 8. Microhardness test

Fig. 9. Electrochemical corrosion test bench

Fig. 10. Microstructures of 1# section of different regions before and after preheating and insulation. (a) Region a1, without preheating; (b) region a1, without preheating, insulation for 15 s after cladding; (c) region a2, preheating 3 s; (d) region a2, preheating 3 s, insulation for 12 s after cladding; (e) region a3, preheating10 s; (f) region a3, preheating 10 s, insulation for 4 s after cladding

Fig. 11. Microstructures of 2# section of different regions before and after preheating and insulation. (a) Region a1, without preheating; (b) region a1, without preheating, insulation for 15 s after cladding; (c) region a2, preheating 3 s; (d) region a2, preheating 3 s, insulation for 12 s after cladding; (e) region a3, preheating10 s; (f) region a3, preheating 10 s, insulation for 4 s after cladding

Fig. 12. Microhardness of coating cross-section. (a) Schematic for measuring microhardness; (b) microhardness curves

Fig. 13. Polarization curves of coating samples located in different regions