【摘要】 为了进一步研究DZ125镍基高温合金在激光熔覆修复后的微观组织性能，本研究采用激光熔覆技术将CoCrW粉末熔覆在基体表面，制备了熔覆层。随后分别对基材（BM试样）和熔覆试样（LC试样）在700℃下进行100 h的高温保温试验。将基材和熔覆试样的表面进行了盐膜涂敷，并在相同高温条件下进行100 h的保温试验，分析高温氧化腐蚀对合金显微组织、显微硬度及成分组成的影响，探究在涂盐热腐蚀环境下熔覆层的耐腐蚀性能。结果表明：从基材到过渡层和熔覆组织，显微硬度逐渐增加，熔覆组织的硬度高达559 HV_0.2,试样在高温下保温后产生了明显的氧化，热盐环境下的试样氧化程度加剧，氧化层的厚度相对无盐环境下出现明显增厚，并且出现了更多的剥落坑。但是相对BM试样，LC试样在2种环境下的氧化程度较轻，这表明激光熔覆组织相对基材具有更强的耐腐蚀氧化性能。更多还原

【Abstract】 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 HV_0.2. 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.更多还原