Investigation of wear and oxidation behavior of Mo additive stellite 21 alloy coatings produced by laser cladding method

In this study, production and characterization studies of different Stellite alloys were carried out for use in the laser cladding method, which is likely to be an alternative protective application in the barrel where wear and erosion damage is high. Within the scope of the study, Stellite 21 powders were used by mixing with Mo powders of similar sizes at 3, 6 and 9% by weight. Samples were obtained by laser cladding process on 32CrMoV12-10, known as barrel steel. Structural and mechanical characterization studies and oxidation studies were carried out in order to reveal the structure and properties of the samples that surface cleaned by grinding after laser cladding. In the samples after laser cladding, it was observed that the density of the Co3Mo intermetallic phase increased in parallel with the increasing Mo% ratio by weight. It was also observed that Mo addition contributed to the formation of carbide phases such as Cr7C3 and Cr23C6. As a result of mechanical characterization studies, it was observed that the hardness of the alloys increased gradually with the %Mo addition and this increased the wear resistance at room temperature. It has been determined that the wear mechanism at temperatures of 500 °C is more complex that is a combined adhesive and abrasive wear mechanism and an additional oxidative wear mechanism operates. To investigate the corrosion performance of the alloys, thermogravimetric (TGA) analyses were carried out by oxidation at 500, 800 and 1000 °C for 24 hours. As a result of the analysis, it was observed that the oxidation resistance of Stellite alloys with Mo addition generally increased. As a result of the study, it was reported that the Mo addition to Stellite 21 alloys improved the mechanical properties of the alloy and increased its oxidation resistance.