Abrasion Resistance of Nickel- and Iron-base Hardfacings

The present study is directed to the problem of hardfacing and restoration of worn industrial equipment. Wear tests were carried out using especially built rig which reproduces working conditions of machinery applied in cement plants. The results of tribological tests on 20 Fe-and Ni-base hardfacings are presented. The effect of hardfacing hardness and chemical composition was evaluated. It was found in SEM examinations that matrix was removed from the zone adjacent to carbides which made them liable to cracking and digging out. The mechanism of matrix removal depended on its hardness and include microcutting and low cycle fatigue. Ni-based hardfacings outper-formed Fe-based coatings. The abrasion resistance of the best Ni-base coating, the Stelcar 6 was 38.7 times higher than that of S235JR steel. Eutectics in Ni-base coatings disturb motion of abrasive grains and force them to rotate instead of sliding over hardfacing surface. Ni-based coatings can be considered in hardfacing or reclamation of numerous industrial components applied in cement plants.