Effect of Carbon Content on Three-body Abrasive Wear Characteristics of 28Cr-3Ni Cast Alloys

Abrasive wear resistance of white cast iron can be improved by adding transition metals due to carbide formation and matrix stabilization. However, it must also be affected by carbon content which has received little attention from researchers. Therefore, this study would investigate the influence of (1.4 and 2.8 wt.%) C on three body abrasive wear characteristics of 28Cr-3Ni cast alloys. High Cr-based multi-component white cast irons (Hi-Cr MWCIs) were used as comparison materials to estimate the life-service of each material. The abrasion test was performed using a rubber wheel abrasion machine test with two different sizes of silica sands (1100HV1). As results, the microstructure consists of martensite (the main matrix) and M7C3 carbide. Additionally, M2C carbide was also precipitated on the microstructure of Hi-Cr MWCIs. Meanwhile, Ni or Co was embedded in the matrix area of materials microstructure. In the case of 28Cr-3Ni, the higher amount of C has a higher carbide volume fraction and hardness leading to be better abrasive wear resistance at high loads. However, the reverse trend occurred at low loads with different sizes of abrasive particles. By comparing to Hi-Cr MWCIs, its abrasive wear resistance is lower owing to the fewer carbide types. In the case of Hi-Cr MWCIs, the higher Cr addition significantly consumes C content during the solidification process resulting to lower hardness and wear resistance. Therefore, it can be concluded that the three abrasive wear performance of materials is strongly influenced by C content, applied load, and abrasive particle size.