Frictional and wear behavior of Cr3C2-NiCr coating on AISI-304 stainless steel

Abstract

Present investigation has been carried out with the aim of determining the sliding wear behaviour of APS (atmospheric plasma spray) chromium carbide nichrome (Cr3C2-NiCr) coating on AISI-304 stainless steel substrate and compare the results with uncoated samples of steel, using ball on disc dry sliding test against zirconium oxide ball. The normal loads applied to the disc were 10 N, 20 N, 30 N and 40 N with sliding speed of 0.4 m/s at ambient temperature. Scanning electron microscopy and energy dispersive X-ray spectroscopy were utilised to analyse the worn surface. Coated samples exhibit the higher wear resistance as compared to uncoated samples because of higher hardness and uniform and dense microstructure. There were two main wear operating mechanisms observed by SEM, adhesive wear and abrasive wear for uncoated samples, whereas coated samples exhibited adhesive wear, delamination and oxidation. Oxide layer formation occurred on the surface of coated samples, which prevents direct surface-to-surface contact and reduces the friction. A stable friction is achieved after a certain period of time for coated and uncoated samples. Coated samples exhibited lower coefficient of friction compared to uncoated samples at higher loads. It could be attributed to increase in oxidation as the load increases. © 2022 Informa UK Limited, trading as Taylor & Francis Group.