A layer of nickel-based superalloy Inconel625 was cladded on the surface of the water wall steel plate of waste incineration boiler by laser additive remanufacturing to fabricate 20 G/Inconel625 composite. The effects of laser power on the dilution rate

macroscopic morphology

microstructure and hardness of Inconel625 alloy composite layer were investigated. The results indicate that with the power of the bottom layer and the surface layer of 5 000 W

the scanning speed of 5 000 mm/min

the powder feeding rate of 40.3 g/min

and the lap rate of 60%

the Fe dilution rate of the composite layer is less than 5%

and the surface is smooth with absence of pores. The structure of bonding zone in the composite layer is characterized by cellular dendrite and secondary dendrites

while that of interlayer remelting zone is columnar grain

which is surrounded by network secondary dendrites

and that of primary melting zone in the surface layer presents equiaxed grain.