Arc Supersonic Spraying Process On The Effects Of Interfacial Properties

In this paper, further theoretical analysis is conducted on the principle of arc spraying process, based on the current state and development of arc spraying technology at home and aboard. Combination mechanism and high-temperature corrosion mechanism of FeCrAl coating prepared by arc spraying process are studied, which provides the theoretical basis for the extensive application of the process optimized and coating with high-temperature corrosion.FeCrAl-coating produced by supersonic velocity electric arc spraying technology (HVAS) on the structural materials exhibits excellent high-temperature corrosion resistance and good wear-resistant features. So these coatings can be used in the field of prevention of corrosion in high-temperature environments and resistance to wear for the water-wall tubes of boilers in heat-engine plant, and they might rapidly lead to the industrial applications. In this study, microstructures of the FeCrAl coating produced by HVAS have been analyzed by using modern testing techniques. The bondstrength, high-temperature corrosion resistance, thermal shock resistance and porosity of coatings produced by HVAS have been studied through a series of experiments. Main results are summarized as follows:The light microscope is used to analyze the microstructure of the FeCrAl coating produced by HVAS. The microscopic structure of coatings appears typical layered structure characteristics. The coatings have high density, haven't coarse pore, and have very thin oxide films and a small quantity of gas porosity. The phase composition of surface of FeCrAl coating is composed of iron-based solid solution and a little Fe₂O₃.The bond strength of FeCrAl coating produced by HVAS has been studied .The bond strength between FeCrAl coating and NiAl bonding coating is more than the bond strength between NiAl bonding coating and base metal. Moreover, the study indicates that the process of producing NiAlbonding coating previously can be omitted if the blast sanding has been carried out on the surface of base metal .The fracture mechanism of coatings produced by HVAS in the cycle of heating and cooling is put forward. The difference of the thermal physical property between coatings and base metal results in the forming of thermal stress in the inner of coatings. Consequently, the coatings spall from the base metal.The study indicates that corrosion resistance of FeCrAl coating by HVAS is better than corrosion resistance of 45# steel. The loose Fe2C>3 formed in low-temperature hot corrosion of FeCrAl coating is the main reason why the corrosion resistance of FeCrAl coating is.Supersonic velocity arc spraying using FeCrAl wires being a new type, high quality, high efficiency, and low cost technique to produce high-temperature environments and corrosion resistant coating. has excellent potential for industrial application in the protection of water wall tubes of boilers in heat-engine plant.