Effect of welding conditions on erosive wear of hard-faced Co-based alloy layer

Abstract

Degradation of materials due to the impact of solid particle is a major material wastage process. Modifying the surface of materials can be considered to be a potential method of improving the resistance to erosion. In the present days, weld hard-facing is a popular surface modification process. Engineering industries are opting for hard-facing because of its low capital cost, low operational cost, and operational simplicity. In the context of erosion-resistant hard materials, a series of Co-based alloys that can be deposited by hard-facing is one of the most suitable materials. The present analysis has been carried out to evaluate the influence of processing conditions of hard-faced Co-based alloyed layer on solid particle erosion response at ambient temperature. These layers were deposited on mild steel substrate by weld hard-facing. The mechanical properties and microstructural features of these coatings were evaluated by means of X-ray diffraction technique, optical microscopy, scanning electron microscopy, and microhardness tester. Erosion rate was measured using an air jet erosion test rig. The eroded surface morphology and the transverse section of eroded surfaces were viewed using scanning electron microscopy. The results showed that hard-facing improves erosion resistance of the substrate. The erosion responses of most of the coatings were ductile. Material loss from hard-faced coating was by formation of lips followed by their fracture which initiated in the interdendritic regions.