Cailiao Baohu (Apr 2022)
Effect of Silicate Sealing Agent on High-Temperature Erosion Wear Properties of Thermal Spraying 304 Stainless Steel Coating
Abstract
The coating prepared by thermal spraying process often has many pores. In order to make up for the problems of corrosion resistance and erosion performance degradation caused by pores, 304 stainless steel coating was prepared on the surface of Q235 steel by high-speed arc spraying, the pore sealing agent was used to treat the coating pores brought by the thermal spraying process. The pore sealing agent was prepared with alkali metal silicate base material, mica powder and SiO2 nanoparticles as fillers, and the coating was sealed by brush-coating method. The high-temperature erosion wear resistance of sealing layer and spraying coating was studied. SEM and EDS were used to analyze the micro morphology and composition of the sealing layer and spraying coating. The erosion wear performance and mechanism of the sealing layer and the spraying coating at 25 ℃ and 650 ℃ were studied. The erosion wear life of the sealing layer and spraying coating was estimated by the experimental erosion wear amount. Results showed that the sealing layer had no internal cracks and was tightly combined with the spraying coating, but there were many pores inside. The erosion wear performance of the sealing layer at low impact angle was better than that of the unsealed coating. As the erosion temperature increased from 25 to 650 ℃, the erosion wear amount of the sealing layer was improved by about 20%, and the erosion wear performance of the sealing layer decreased. The erosion wear mechanism of the sealing layer and spraying coating was the combined action of ploughing and cutting at low erosion impact angle, and crushing damage at high impact angle. At low impact angle, the sealing layer had better erosion wear resistance than the spraying coating. To a certain extent, the sealing layer could effectively enhance the erosion wear resistance of the spraying coating.
Keywords
