Abstract: Nickel-based alloy coatings are deposited on the surface of crust breaker made of Q235 steel through plasma arc welding with the nickel-based powders containing 50% WC, 40% WC and 30% WC+TiC, respectively. And the microstructure, chemical composition, micro-hardness, abrasive resistance and corrosion resistance are examined on the samples investigated by using optical microscope(OM), scanning electron microscope(SEM), Vickers hardness tester and friction and wear testing machine. The microstructures of the coatings are γ-Ni solid solution and hard dispersed compound particles, such as WC, (Ti, V) C, etc. The coatings with low dilution rate possess a better metallurgical bonding with the matrix metal, and better electrolytic corrosion resistance compared with the Q235 matrix. The Nickel-based alloy coating containing 30% WC+TiC has the highest wear resistance and hot corrosion resistance in comparison with the coatings containing 50%WC and 40%WC. Therefore, the Nickel-based alloy coating layer containing 30% WC+TiC has the optimum comprehensive properties and extensive application prospect.

Key words: crust breaker, Ni based powder, plasma arc welding, titanium carbide