Selection of Test Sands for Abrasive Wear of High-chromium Cast Irons

Abstract

Dry sand/rubber wheel tests are used for low-stress abrasive wear. Test sands have to be selected to simulate an actual abrasive. But, hardness, roundness and size of sands have usually been a major concern. The present paper, restricting to abrasive wear in coal pulverizing mill, describes an experimental study on the selection of test sands based on similarity in abrasivity against white cast irons. Single-scratch tests were performed using a rubber wheel tester. The width to depth ratio of a groove, groove area and load on a single grain were measured or calculated for five kinds of martensitic white cast irons scratched by various sands. They were compared with those by hard particles extracted from coal. Two commercially available sands were selected, having similar abrasivity with larger and smaller sands extracted from coal. The characteristics of grooves such as the groove area were correlated with the wear rate in conventional sand/rubber wheel tests. Demonstrating strong dependence of the wear resistance on the size of sands, it was concluded that both two selected sands have to be used for rubber wheel wear tests as far as abrasive wear for coal pulverizing mill is concerned.