Microstructure and Corrosion Resistance of DZ125 Superalloy via Laser Cladding

To further investigate the microstructural properties of DZ125 nickel-based superalloy after laser cladding repair，this study employed laser cladding technology to deposit CoCrW powder onto the substrate surface，thereby fabricating a cladding layer.Subsequently，both the base material (BM specimen) and the cladded specimen (LC specimen) underwent a 100 h high-temperature exposure test at 700 °C.Salt films were applied to the surfaces of both the base material and cladded specimens， followed by a 100 h exposure test under identical high-temperature conditions.Meanwhile， the effects of high-temperature oxidative corrosion on the alloy’s microstructure， microhardness and compositional characteristics were analyzed， and the corrosion resistance of the cladding layer under salt-deposited hot corrosion conditions was explored.Results showed that the microhardness increased gradually from the base material to the transition layer and the cladding structure， and the hardness of the cladding structure was up to 559 HV0.2.After high-temperature exposure， the specimens exhibited significant oxidation， with those in the hot salt environment demonstrating exacerbated oxidation severity.Compared to salt-free conditions， the oxide layer thickness showed a significant increase under salt deposition，accompanied by more extensive spalling pits.However，compared to the BM specimen，the LC specimen demonstrated milder oxidation in both environments， indicating that the laser-cladded microstructure possessed superior corrosion and oxidation resistance relative to the base material.