Erosion behaviour of NiCrBSi coating under mining conditions

Abstract

Grey cast iron material was taken up for the investigation with and without the application of NiCrBSi coating by high velocity oxyfuel process on its substrate. Prominent influencing factors such as velocity and angle of impingement were chosen for the study of the erosive wear behaviour involving two different pH conditions of 3 and 7 that conform to the mining conditions. X-ray diffraction characterisation was used to identify and confirm the phase formation in the coating. Wear morphology was also studied using scanning electron microscopy characterisation techniques. NiCrBSi coating at low angles of impact reveals that the degradation is by shallow ploughing and abrasion. At normal impact, erosion takes place by deep indentation that forms lips and craters, which are subsequently removed as platelets by a fatigue process. In the case of base material, the material removal from the surface is predominantly by ploughing mechanism.