Erosive Wear Behavior of Nickel-Based High Alloy White Cast Iron Under Mining Conditions Using Orthogonal Array

Abstract

Nihard Grade-4, a nickel-bearing cast iron widely used in slurry pumps and hydrodynamic components, is evaluated for its erosive wear response under mining conditions using a statistical approach. Experiments were conducted by varying the factors namely velocity, slurry concentration, angle of impingement, and pH in three levels, using L9 orthogonal array. Analysis of variance was used to rank the factors influencing erosive wear. The results indicate that velocity is the most influencing factor followed by the angle of impingement, slurry concentration, and pH. Interaction effects of velocity, slurry concentration, angle of impingement, and pH on erosion rate have been discussed. Wear morphology was also studied using SEM characterization technique. At lower angle (30°) of impingement, the erosion of material is by micro fracture and shallow ploughing with the plastic deformation of the ductile austenitic matrix. At the normal angle (90°) of impingement, the material loss from the surface is found because of deep indentation, forming protruded lips which are removed by means of repeated impact of the erodent.