Development Of Nickel-Base Cored Wire Against Corrosion And Erosion At Elevated Temperature

Flue gas and fly ash at elevated temperature induce boiler tube rapid thinning or exploding at coal fired power station. To solve this problem, nickel-base cored wires (including NiCr-Cr3C2 series and NiCrBSi series) against corrosion and erosion at elevated temperature are designed in this article. Cr-B-Si alloy powder prepared is used to increase the composition of chromium and boron element and improve the coatings' properties.The research on properties of nickel-base coatings indicates that nickel-base cored wires have good manufacture process. Coatings have good adhesive strength. Rare earths can refine microstructure and increase adhesive strength and decrease porosity. The addition of nickel element and chromium element increases coatings' properties of heat shock resistance and corrosion resistance. Coating's hardness becomes high with an increase of carbide and boride. The hot corrosion test shows that corrosion resistance of nickel-base coatings is better than that of 20g steel and PS45.The erosion tests at elevated temperature show that nickel-base coatings' erosion behavior is in between plasticity and fragility. Coatings' erosion resistance changes with temperature. CrB2# has good performance at 6500C, and it is better than NiCr-Cr3C2 series; NiCr5# has good property at 7500C. Appearance of coatings is furrow at low angle of incidence, it is notch at high angle of incidence through SEM analysis.