Tribological and Corrosion Behaviors of 304L and 317L Stainless Steel Coatings for Mechanical Parts Subjected to Friction and Wear

Ball valves were subjected to severe working conditions that shortened the service life of their components and required additional costs for their maintenance and renovation. The ball valves were mainly made from 304 stainless steels (304 SSs). However, its low hardness and corrosion resistance had limited its use. In this study, 317L and 304L stainless steel coatings (317L SSC and 304L SSC, respectively) with thicknesses of 432 and 434 μm respectively were deposited on carbon steel substrates using the twin-wire arc spray system and were comparatively investigated. The mechanical, tribological, and electrochemical properties of the bulk 304 SS were also investigated. Microstructural analysis was carried out using x-ray diffraction, Raman Spectroscopy, Scanning Electron Microscopy and energy-dispersive x-ray spectroscopy. The surface roughness was characterized using Atomic Force Microscope. Lower porosity and oxides content were obtained for 304L SSC, while smooth surface with lower roughness were observed for 317L SSC. Hardness measurement revealed that 317L SSC had higher hardness than 304L SSC. The tribological characterization results showed that both coatings had excellent friction coefficient and wear resistance. The electrochemical tests were carried out in a 3.5wt.% NaCl solution and their results revealed that 304L SSC had a high corrosion resistance.