Effect of Microstructural Degradation on Solid Particle Erosion Behavior of 2.25Cr-1Mo Steel

Abstract

The present article evaluates the influence of independent control factors such as microstructural degradation, impact velocity, impingement angle, and erodent size on solid particle erosion behavior of 2.25Cr-1Mo steel using a statistical approach. Microstructural degradation in this steel has been introduced as a result of thermal aging corresponding to Larson-Miller parameter (LMP) values of 33,012, 35,402, 37,846, and 38,374. Solid particle erosion tests were carried out using a sand blast-type test rig following a well-planned experimental schedule based on Taguchi's orthogonal arrays. The erosion rate of this steel decreases with increase in the severity of thermal aging. This observed phenomenon could possibly be attributed to spheroidization of lenticular-shaped carbides to globular-shaped carbides as a result of increase in the severity of thermal aging. With the help of signal-to-noise ratios and analysis of variance (ANOVA), an optimal combination of control factors to minimize the solid particle erosion behavior of 2.25Cr-1Mo steel was determined. Among all four control factors, the LMP representing the extent of thermal aging is the most significant control factor influencing the solid particle erosion behavior of this steel, followed by impingement angle, impact velocity, and size of erodent. Results indicated that the LMP has a greater static influence of 46.33%, impingement angle has an influence of 42.51%, impact velocity has an influence of 7.47%, and size of erodent has an influence of 1.13% on solid particle erosion of this steel. Material loss during solid particle erosion of 2.25Cr-1Mo steel is found to be ductile in nature and primarily controlled by cutting and ploughing action.