This study aims to investigate the differences in the microstructure of the overlap zone (OZ) and non-overlap zone (NZ) of Ni1725–WxC laser clad coating, compare the erosion–corrosion resistance under varying flow velocities in high-temperature and pressure environments and explain the regional variations in the failure mechanisms.
The OZ and NZ of Ni1725–WxC laser clad coating were comparatively analyzed using scanning electron microscopy with energy dispersive spectroscopy, X-ray diffraction, electron back scatter diffraction and X-ray photoelectron spectroscopy. The erosion–corrosion resistance was evaluated electrochemically in a high-temperature and high-pressure autoclave.
The OZ exhibited inferior corrosion resistance due to grain coarsening, a higher Fe dilution rate and increased secondary phase content. Fluid erosion accelerated corrosion by damaging the protective corrosion product film and enhancing material exchange.
Investigation from the perspective of local variations reveals the macroscopic inhomogeneity in the corrosion resistance of the Ni1725–WxC laser clad coating.
