Combined erosion-corrosion poses a considerable problem to the design of long lifetime metallic components in energy conversion systems.To gain some insight into this problem, scales were formed on stainless steel at elevated temperature and subsequently were eroded at room temperature to determine the nature of the erosion rates and the mechanism of scale removal. Thin corrosion scales were formed on 310 stainless steel and an experimental Fe-18Cr-5Al-1Hf alloy at high temperatures (9ooo and 980°C) in gas mixtures with various levels of oxygen and combined oxygen-sulfur. The corroded specimens were eroded at room temperature in an air-solid particle stream using 50~m SiC at 60 ms-1. The conditions of the corrosive exposures, the rates of erosion of these scales and the microscopic appearance of the eroded surface were correlated to determine the mechanism of thin scale erosion.

Materials resistant to high temperature corrosion and small particle impact erosion are necessary in the design and construction of energy -1-