The Fabrication And High Temperature Chlorine Corrosion Properties Analysis Of Laser Cladding Nickel-Based Alloy Coating

Waste incineration power generation as a clean and efficient means of waste disposal,it is playing an increasingly important role in the future development of our country.As a mixed waste,garbage is rich in high-level alkali metal elements and chlorides,causing severe high-temperature chlorine corrosion on the water wall tubes and superheater tubes in the boiler during high-temperature incineration.In order to further explore the high temperature corrosion mechanism of the material and the high temperature corrosion resistance of the laser cladding layer,this topic firstly analyzes the actual corrosion failure of the waste power plant,and prepares the C22 on the traditional 20G quenched and tempered steel by laser cladding technology.The Hastelloy cladding layer and the Inconel 625 alloy cladding layer were finally subjected to high temperature molten chloride corrosion test on three materials.Pure NaCl and pure KC1 were selected as corrosion reagents to simulate the high temperature molten salt corrosion environment of waste incineration power plant,and 10 cycles(120 hours total)isothermal corrosion experiments were carried out at 450?,550?,650? and 750?.The microstructure,microstructure and phase composition of the corrosion products were analyzed by scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS)and X-ray diffraction(XRD).The corrosion resistance weight loss curves were used to observe the high temperature corrosion resistance of the three materials.to evaluate.The experimental results show that the corrosion phenomenon of 20G steel in the simulated environment is consistent with the actual failure of the waste electrical power plant,indicating that it is of practical significance to evaluate the high temperature and chlorine corrosion resistance of the three materials in the two humic agents.By comparison,the corrosion resistance of C22 Hastelloy cladding layer and Inconel 625 alloy cladding layer is better than that of 20G steel,which is mainly attributed to the formation of oxide layer of NiO,Cr2O3 and MoO2 on the surface of the material,compared with that of 20G steel.Iron oxide FexOy(Fe2O3,Fe3O4)has higher stability;and at temperatures above 650?,Inconel 625 alloy cladding layer exhibits better corrosion resistance than C22 alloy cladding layer,which may be due to the higher stability of NbO is formed at high temperatures,and its presence allows Cr2O3 and NiO to remain in the corrosion cycle for a longer period of time.