燃气轮机在海洋环境下的热腐蚀与防护技术研究进展

针对海洋环境下舰船燃气轮机的热腐蚀现状,从热腐蚀的机理研究着手,基于不同阶段提出的热腐蚀模型理论,分析了高温和低温两种热腐蚀类型的发生过程和表现特征,指出热腐蚀实质上是以Na2SO4为主导的熔盐沉积共晶物与金属基体发生反应而导致金属材料加速氧化的过程。在此基础上,详细介绍了三种涂层防护技术—扩散涂层、覆盖涂层和热障涂层,并根据这三种涂层的发展阶段和功能特性,分析了其在制备工艺、作用机理和应用领域上表现出的差异性,重点强调了热障涂层(TBCs)在当前的发展境况。结合世界各国研究者开展的代表性工作,全面综述了国内外在舰船燃机热腐蚀防护领域的研究进展,重点描述了以硫酸盐为主的腐蚀介质中,金属材料的热腐蚀表现特征,并展示了数值模拟、热力学模拟等方法在热腐蚀研究上的应用案例。最后,对舰船燃气轮机涂层防护技术的发展方向进行了展望,提出发展新一代环障涂层(EBCs)是提高燃气轮机综合防护能力的有效技术手段。

Research Progress of Hot Corrosion and Protection Technology of Gas Turbine under Marine Environment

In view of the hot corrosion status of gas turbine operating under marine environment, the occurrence process and performance characteristics of two types of hot corrosion at high temperature and low temperature were analyzed based on hot corrosion model theory put forward at different stages from the mechanism research on hot corrosion. It was pointed out that hot corrosion was essentially the process of accelerated oxidation caused by the reaction between the dominant Na2SO4 and the metal substrate. On this basis, three kinds of protective coatings were introduced in detail: diffusion coatings, overlay coatings and thermal barrier coatings (TBCs). According to the development stages and functional characteristics of the three coatings, the differences in preparing technique, mechanism and application field were expounded, while the current development of TBCs was emphasized. Based on the representative work of researchers from all over the world, domestic and foreign research progress on gas turbine hot corrosion resistance were systematically summarized. The hot corrosion behavior of metals in sulfate corrosion medium was mainly described and the application of numerical and thermodynamic simulation method in analyzing hot corrosion was presented. Finally, the developing trend of coating technologies for gas turbine is prospected, and it is also proposed that the new generation of environmental barrier coatings (EBCs) is an effective technological means to improve the comprehensive protective performance of gas turbine.