Erosion wear of boiler tubes occurs from room temperature to high temperature and is accelerated by oxidation and hot corrosion above 400 °C temperature. The demand for hard coatings compatible in improving erosion, oxidation and hot corrosion resistance while maintaining the desired mechanical properties of the base material is increasing with the advancement of technology. In this work, WC-12Co coating, Stellite 6 coating and Stellite 21 coatings have been deposited on SAE213-T12 boiler steel using a Detonation gun (D-gun) spray method, and their erosion performances have been evaluated at 400 °C temperature using an air jet erosion tester. The erosion tests have been carried out using the alumina erodent particles at 30° and 90° impact angles. The surfaces of the as-sprayed coatings and the specimens eroded at 400 °C temperature were analysed using a scanning electron microscope (SEM) equipped with energy-dispersive X-ray spectroscope (EDS). Stellite 21 coating has shown comparatively lower erosion rate than the Stellite 6 and WC-Co coatings at 400 °C temperature attributed to the formation of protective oxides of chromium and cobalt at 400 °C. The effects of microhardness and temperature on the erosion behaviours of the coatings at 400 °C temperature are discussed. The oxide layers of chromium and cobalt and accumulation of hard phases of nickel, molybdenum and carbon contributed in the protective behaviour of the deposited Stellite 6 and Stellite 21 coatings at 400 °C. The oxidation enhanced erosion wear is observed at 400 °C temperature for all the coatings.

锅炉管的腐蚀磨损从室温到高温都会发生，并且在400°C以上的温度下会因氧化和热腐蚀而加速磨损。随着技术的进步，对在改善耐蚀性，抗氧化性和抗热腐蚀性的同时保持基础材料的所需机械性能的相容性硬质涂层的需求在增加。在这项工作中，使用爆轰枪（D-gun）喷涂方法在SAE213-T12锅炉钢上沉积了WC-12Co涂层，Stellite 6涂层和Stellite 21涂层，并在400°C的温度下使用以下方法评估了它们的腐蚀性能：喷气侵蚀测试仪。使用氧化铝腐蚀颗粒在30°和90°冲击角下进行了腐蚀测试。使用配备有能量色散X射线光谱仪（EDS）的扫描电子显微镜（SEM）分析喷涂后的涂层表面和在400°C温度下腐蚀的样品。在400°C的温度下，Stellite 21涂层的腐蚀速率比Stellite 6和WC-Co涂层低，这归因于在400°C时形成了铬和钴的保护性氧化物。讨论了显微硬度和温度对涂层在400°C温度下的腐蚀行为的影响。铬和钴的氧化物层以及镍，钼和碳的硬相的积累有助于在400°C时沉积的Stellite 6和Stellite 21涂层的保护性能。对于所有涂层，在400°C的温度下观察到氧化增强的腐蚀磨损。