Study on microstructure and cyclic oxidation behavior of WC-CoCr cermet based Plasma sprayed coatings on austenite steel

Abstract

Abstract This article studies the cyclic oxidation behavior of WC-10Co-4Cr powder coatings obtained by plasma spraying on AISI316L austenitic stainless steel in an ambient air at 850°C for 50 cycles. Weight change observations of coated samples have been used to establish the oxidation kinetics, and the outcomes for the uncoated and coated specimens were compared. Utilizing scanning electron microscopy (SEM) and X-ray diffraction (XRD) the coating's microstructure has been identified before and after oxidation. XRD, SEM and energy dispersive spectroscopy (EDS) were utilized to analyse the scales surface-morphology of coated austenite steel samples following the oxidation cycle. The uncoated AISI 316L Steel had severe spalling, peeling-off, and sputtering from its oxide scale. Additionally, the scale is rich in Fe2O3, which contributed to the large weight gain. The findings showed that coatings outperform uncoated materials in terms of oxidation resistance. The coating lowered the weight gain of austenite 316 steel by 84.34%. It was discovered that the protective WO3 and Cr2O3 phase generated on the oxide scale provided higher oxidation resistance.