Comparative study of jet slurry erosion of martensitic stainless steel with tungsten carbide HVOF coating

Abstract

This work evaluates the behavior of a martensitic stainless steel (AISI 410) thermally treated by quenching and tempering with a tungsten carbide (86WC-10Co-4Cr) coating obtained by high-velocity oxygen fuel (HVOF) thermal spray deposition, analyzing the volume loss under erosive attacks at 30° and 90° incidence angles by using jet slurry erosion equipment with electrofused alumina erodent particles. Firstly, the characterization of the samples was carried out in terms of the microstructure (SEM), thickness, roughness, porosity, and microhardness. Then, samples were structurally characterized in the identification of the phases (XRD and EDS) present in the coating, as well as the particle size distribution (LG) and morphology of the erodent. It was determined that the tungsten carbide coating presented better resistance to jet slurry erosion wear when compared to the martensitic stainless steel analyzed, which is approximately two times higher for the 30° angle. The more ductile and brittle natures of the substrate and the coating, respectively, were evidenced by their higher volumetric erosion at 30° for the first and 90° for the latter, as well as their particular material removal mechanisms. The enhanced resistance of the coating is mainly attributed to its low porosity and high WC-Co content, resulting in elevated mechanical resistance.