Erosion behaviour of boiler component materials at room temperature and 400 °C temperature

Abstract

Degradation of boiler tube components in Indian thermal power plants is mainly done through solid particle erosion due to exposure in erosive ash environment. Some important parameter such as hardness, erodent velocity, temperature, impact angle, shape and size are majorly affected the erosion wear. In this study, the erosion wear behaviour of SAE 208 grade steel, SAE213-T12 boiler steel, SAE213-T91 boiler steel and IS 2062 structural steel were investigated using an air jet erosion test rig. The erosion tests were carried out at the impact angles of 30° and 90°, impact velocity of 42.3 m/s at room temperature and 400 °C. The position of sample holder was adjusted in such a way that erosion wear scar occur at the central region of the samples. For each experiment, the erosion test was continued until the steady state erosion rate was achieved as per ASTM standard. The variation in erosion rate data has been plotted against cumulative mass of erodent for boiler and structural steel samples. The steady state erosion rates for different steel samples are calculated and compared. The surfaces of tested samples are analyzed using scanning electron microscopy to understand the erosion mechanism. The results showed that the ductile behaviour of erosion mechanism is dominated at both room temperature and 400 °C temperature. Mechanism involved at 90° impact angle is plastic deformation with formation of craters and at 30° impact angle is cutting and ploughing.