Microstructure and Hardness of Fe-Based Coating by Plasma Cladding

Plasma cladding experiments were carried out on Q235 steel with Fe-Cr-Ti-C powder. Microstructure and micro-hardness of the composite coatings were investigated by means of optical microscopy (OM), scanning electron microscopy (SEM) and electron probe micro-analyzer (EPMA) and micro-hardness tester. The results indicated that the grains of the cladding coatings with Ti are much finer than that of the Fe-based cladding coating without Ti. Compared with the cladding coatings without Ti, there are more shingle crystals in the cladding coatings with Ti and the hard phase (Cr,Fe)7C3of the eutectic in the coatings increase gradually. The average hardness value of the four cladding coatings is respectively 486.5 HV0.1and 558.8 HV0.1.