Parameter optimization for tungsten carbide/Ni-based composite coating deposited by plasma transferred arc hardfacing
(1. School of Materials Science and Engineering, Tongji University, Shanghai 201804, China;
2. Railway and Urban Rail Traffic Academy, Tongji University, Shanghai 201804, China;
3. College of Automotive, Tongji University, Shanghai 201804, China)
2. Railway and Urban Rail Traffic Academy, Tongji University, Shanghai 201804, China;
3. College of Automotive, Tongji University, Shanghai 201804, China)
Abstract: Ni-based composite coatings with a high content of tungsten carbides (Stelcar 65 composite coatings) were synthesized by plasma transferred arc (PTA) hardfacing. The welding parameters of Stelcar 65 composite coatings were optimized by orthogonal tests. The PTA welding parameters including welding current, powder feed rate and welding speed have significant influence on the tungsten carbide degradation. The values for the optimum welding current, powder feed rate and welding speed were determined to be 100 A, 25 g/min and 40 mm/min, respectively. The produced WC/Ni-based composite coatings were crack- and degradation-free. The microstructure of deposited layers, as well as the microstructure and microhardness of the optimal coating were further analyzed.
Key words: plasma transferred arc hardfacing; Ni-based composite; microstructure; welding parameter optimization