Study on Abrasive Resistance of Arc Spraying Fe-Based Coatings Containing Cr₃C₂ Hard Phase

Thermal spray processes are widely used to protect materials and components against wear, corrosion and oxidation. As commercial arc sprayed coatings have been used to a limited extent in applications involving erosion and abrasion wear, developing attractive wear resistance arc sprayed coatings has been found necessary. Abrasive wear testing was carried out on four Fe-based composite coatings containing varied contents of Cr₃C₂ particles as hard phases. Scanning electron microscopy (SEM) was used for observing the surfaces of the composite coatings, and wear mechanisms of the coatings were discussed on the basis of the observation. The results obtained from MLS- 225 wet sand/rubber wheel test showed that the abrasive wear resistance of composite coatings with Cr₃C₂ hard phase is about 28 times higher than that of Q235 mild steel. The coating method was proved effective in producing a uniform and dense lamellar structure. The excellent abrasive resistance of the composite coatings with Cr₃C₂ particles were found to be related to three major factors: enhanced bulk hardness, compact lamellar structure and strong bonding between matrix and hard phase, as well as a load supporting system constructed by the hard phase structure.