Effects of thermally grown oxides on erosion wear of surfaces at high temperature for falling particle concentrating solar power

Degradation of component materials due to erosion and abrasion wear, particularly at high operating temperatures, is a challenge to be addressed in the development of Gen3 falling particle concentrated solar power (CSP) systems. This paper examines the impact of high temperatures on oxide growth and presents a comprehensive erosion study of grown oxides on several structural materials—SS316, In800H, and In718—for use in system components. The formation of the oxide layer thickness and mass gain are strongly influenced by the annealing temperature and duration. The grown oxides are shown to protect the underlying surface from erosion wear. The erosion rate is reduced by 26–53 % for SS316, 18–47 % for In800H, and 41–65 % for In718, compared to the bare alloys, depending on the operating temperature. An analytical relation is developed to predict the time evolution of the erosion rate of the grown oxides based on experimental data. An Arrhenius relationship is also presented to describe the temperature-dependent steady-state erosion rate of the grown oxides on the different alloy materials. This study provides insight into the competing mechanisms of oxide growth and wear. It specifically focuses on the behavior of oxide layers during the high-temperature operation of a falling particle CSP system.