Microstructure, Wear Resistance and Corrosion Resistance of a Fe-based Alloy Laser Clad onto 27SiMn Steel
L.J. Cui, P.X. Wang, S.R. Guo, Y.L. Cao, W.H. Zeng, G. Cheng and H.Y. LI
The hydraulic column is the key component of the hydraulic support in the mining environment. To improve a hydraulic column’s reliability and service life, the Fe-based laser clad layer was prepared on 27SiMn steel substrate using a high power diode laser (HPDL). The results show that the best process parameters are the laser power of 3000 W, the scanning speed of 5 mm/s, the feeding fraction of 16 g/min and the lapping rate of 50%. The macroscopic morphology of the laser clad layer has no cracks, pits and other defects. The laser clad layer has a fine and uniform microstructure and can form a metallurgical bonding with the 27SiMn steel substrate. Elements distribution is uniform and it appears fluctuation around the melting line. The cladding hardness is 1.3 times higher than the substrate and the wear resistance is 7.7 times higher than the substrate. The self-corrosion potential of the laser clad layer is significantly shifted positively and has a significant passivation region. After 96 hours of salt pray corrosion test, the surface of the laser clad layer is still smooth. The laser clad layer has better corrosion resistance and performance than the substrate, which can meet the requirements of hydraulic support in the mining environment.
Keywords: High power diode laser (HPDL), hydraulic column, 27SiMn steel, Fe-based alloy, laser cladding, process parameters, microstructure, wear resistance, corrosion resistance