A study of T11 boiler steel protection by cold sprayed Inconel 738 coating against high temperature erosion

Abstract

Abstract The failure of boiler tubes, superheater tubes and turbine blades, due to high-temperature erosion, is a serious issue in the power generation industry. The investigation focuses on the applicability of cold sprayed Ni-based coatings for boiler tubes and turbine blades, by improving the erosion resistance of the base material. The present work includes high-temperature solid particle erosion behaviour of Inconel 738 (IN 738) coatings deposited on ASTM SA213 T11 steel substrate, by means of cold spray deposition. A comparison of the temperature effects on the erosion performance of coated and uncoated samples have been examined by an air jet erosion tester. After the erosion tests, both uncoated and coated specimens were characterised using a scanning electron microscope (SEM) and X-ray diffraction (XRD) analysis. Erosion resistance of the coating is approximately three and two times higher than T11 steel at 700°C for 30°and 90° impact angles, respectively. Consequently, cold spray IN 738 coating offers higher resistance to high-temperature erosion than that of the base steel, which is essential in a power plant environment.