Material Degradation at High Temperature

Materials used for high temperature applications are subjected to various types of degradation phenomenon such as high temperature corrosion, erosion-corrosion, overheating, solid particle abrasion, wear, etc. Boiler tubes used for super-heaters and re-heaters in steam-generating systems are subjected to erosion-corrosion at high temperature, resulting in tube wall thinning and premature failure. The present study investigates the high temperature erosion-corrosion resistance of D-gun sprayed coatings on "ASTM-SA210-GradeA1" boiler tube steel in actual industrial environment. SEM/EDAX, XRD and X-ray mapping analysis is done to reveal the microstructural and compositional features of coated boiler tube steel. The deposited coatings on Grade A1 steel exhibit uniform and dense microstructure. Thermogravimetric technique is used to investigate the erosion-corrosion behavior of uncoated and coated boiler tube steel at high temperature for 1000 hours. SEM/EDAX, XRD and X-ray mapping techniques were used to analyse the corrosion products.