Cavitation Erosion Investigations of Hard Carbide and Nitride Based Novel Coatings Manufactured by Plasma Spraying

Cavitation erosion (CE) poses a significant challenge in the operation and maintenance of hydropower turbines, leading to substantial economic and operational losses. This study addresses this issue by investigating the effectiveness of plasma-sprayed coatings in mitigating CE on SS316 steel. Si3N4+TiC + VC and Cr-Ni based coatings were applied using a plasma spraying process. The research encompasses a comprehensive analysis of the coatings' characteristics, including microhardness, surface roughness, porosity percentage, and coating thickness. Furthermore, CE tests were conducted under various conditions, considering factors such as impingement angle, stand-off distance, and jet velocity. The eroded surfaces were analyzed using scanning electron microscopy (SEM) to gain insights into the failure modes. The findings demonstrate that the Si3N4+TiC + VC and Cr-Ni based coatings significantly enhance the resistance of SS316 steel to CE.