针对极端环境中材料面临的高温、高浓度HCl的苛刻工况，采用XRD、SEM、EDS和EPMA等研究手段，研究了一种镍基高温合金在960 ℃、5%HCl + 0.5%O₂ + Ar (体积分数)气氛条件下的热腐蚀行为，腐蚀时间长达200 h。通过对比不同时间的腐蚀动力学曲线、腐蚀产物种类及分布、截面腐蚀层结构及元素分布，在分析高温合金腐蚀规律的基础上，初步探讨了高温HCl腐蚀机理。结果表明，960 ℃高温下，合金动力学曲线可分为2段：0~75 h及75~200 h，随时间延长，2段曲线均呈先上升后下降的趋势，生成了大量含Mo、Ti、Cr的挥发性氯化物；腐蚀层中，外层富Cr和Ti的氧化物层保护性较差；没有形成连续的Al₂O₃层；富Ta尖晶石相层具有降低金属离子外扩散的作用；未在试片截面腐蚀层中观察到明显的氯化物富集。研究表明，960 ℃高温下，除了气氛中的HCl、O₂以外，通过氯化-氧化过程，而非中温下的活化氧化过程，生成的Cl₂同样参与了反应，并起到加速氧化的作用。

Superalloys are widely used in aviation, aerospace, energy, transportation, and petrochemical industries due to their excellent properties, such as high-temperature strength, plasticity, fracture toughness, oxidation resistance, and hot corrosion resistance. They are primarily employed in aircraft engines and gas turbines within aviation, marine, and power generation sectors. Furthermore, due to the unique properties of superalloys and continuous advancements of superalloy technology, their applications are expanding into increasingly extreme service environments. In order to simulate the harsh working conditions of materials under high temperature and high concentration HCl environment, the hot corrosion behavior of a nickel-based superalloy was investigated at 960 ^oC in a mixed atmosphere of 5%HCl + 0.5%O₂ + Ar (volume fraction) using XRD, SEM, EDS, and EPMA techniques. Hot corrosion tests were conducted for 200 h. Analysis of corrosion kinetics, types and distribution of corrosion products, and cross-sectional elemental mapping revealed two distinct stages (0-75 h and 75-200 h), both showing an initial increase followed by a decrease in corrosion rate. Volatile chlorides containing Mo, Ti, and Cr formed extensively. The corrosion layer exhibited a poorly protective (Cr, Ti)-rich oxide layer, while no continuous Al₂O₃ layer was observed. The Ta-rich spinel layer inhibited outward diffusion of metal ions. The corrosion layer of the experimental alloy did not exhibit any significant chloride concentration on its cross-section. In addition to HCl and O₂ in the atmosphere, Cl₂ generated through chlorination and oxidation processes reacted with the alloy and played an important role in accelerating oxidation at 960 ^oC, without evidence of intermediate-temperature activated oxidation.