On the microstructure and wear resistance of Fe-based composite coatings processed by plasma cladding with B4C injection

Fe-based composite coatings were fabricated on Q235 steel substrate by plasma cladding. B4C particles were injected at the center and edge of the melting pool as strengthening phase. Scanning electron microscopy and pin-on-disc tribometer were applied to study the microstructure and wear resistance of the coatings. The results showed that the central injected B4C particles dissolved during plasma cladding and cementite generated. Edge injected B4C particles remained and performed metallurgical bonding with the metal matrix. With Fe-based coating containing edge injected B4C particles, wear resistance increased largely and the wear rate became 1/8 of the Q235 substrate. Afterwards, Fe-based coatings with edge injected B4C particles were prepared on real pieces of 50 picks and 12 chutes, which were taken into field probations. Average service lives of the coated picks and chutes increased 3.4 times and 5.6 times, respectively, compared with the conventional 16Mn and 42CrMo pick and chute components.