Evaluation of the wear process of cast iron coated with manganese phosphate

The authors investigated the wear property and wear process of a JIS-FC250 cast-iron surface coated with manganese phosphate, sliding against JIS-SKH51 steel by using an oscillating-rotation wear test rig and SEM-EDX surface analysis. The materials that appeared on the friction surface indicate that the wear process can be divided into three phases, the wear of the coating, the wear of the mixed layer (consisting of cast-iron and the coating) and the wear of the cast iron. The authors found that the value of parameter M, which is the exposure ratio of iron to the coating on the friction surface measured by SEM-EDX analysis, was found to characterize each phase quantitatively. The authors also found that changes in the wear rate are related to parameter M. The best wear resistance of the coated iron was found in the second phase of the wear process, where the exposure ratio on the friction surface ranged from 40 to 80%. The authors obtained the lowest wear rate when the exposure ratio M was 45% and it was less than 1/300 that of the original coated surface.