Tribo-Erosion Analysis of HVOF Colmonoy-88-Coated Pump Impeller Steel in Coal Ash Particle Slurries

Coal ash slurries hold paramount importance in the service life of the coal and mining industries, significantly impacting their operational efficiency and durability. The literature reveals that the prominent dominating parameters such as rotational speed, concentration, time duration, and particle shape and size have a major impact on erosion wear. This research aims to explore the effects of coal ash slurries on Colmonoy-88-coated pump impeller steel, employing a combination of design of experiments (DOE) and digital image analysis (DIA). Through slurry experiments, it is observed that erosion wear increases non-linearly with an increase in influencing parameters. The particle size emerges as the most significant factor, followed by concentration, speed, and time. Additionally, DIA is leveraged to validate the influence of various erodent particle sizes on the erosion wear of the pump impeller steel. Results indicate that coal particles possess irregular shapes and sizes compared to fly ash and bottom ash, consequently resulting in larger erosion wear due to their lowest circularity factor (0.72). Furthermore, smaller particles exhibit lower erosion wear-rates compared to larger ones. This study sheds light on the intricate dynamics of erosion wear in the context of coal ash slurries, offering insights crucial for optimizing pump impeller steel durability in similar operational environments.