Surface coating of stainless steels by HVOF method and investigation of wear properties

Abstract

The surfaces of 316L stainless steels, which are frequently used in the industry due to their mechanical properties, were coated with HVOF method in order to improve their properties. Two different powders for steel surfaces; Diamalloy 2002 (Tungsten Carbide, chromium based) and Metco 7202 (chromium based) powders were prepared in different concentrations. Group A specimens were coated with a mixture of 50% Diamalloy 2002 and 50% Sulzer Metco and Group B specimens were coated with a mixture of 100% Sulzer Metco 7202 by HVOF method. These powders produce coatings that provide wear resistance due to their content. The surface properties of the coated samples were analysed by some methods. Optical and SEM images of all samples were taken and XRD analyses were performed. The coating layer is clearly visible. Some porosity formation was observed. Microhardness values were measured. As a result of hardness measurements, it was determined that the surface hardness increased 4-7 times with the coating. Linear abrasion tests were performed with CSM abrasion tester. It was observed that the abrasion resistance increased. After the abrasion test, roughness measurements and SEM-EDS analyses of the abraded surfaces were performed. Abrasive and adhesive wear formations are present on the worn surfaces.