There is high demand for refurbishment of damaged mechanical components in power plants. Twin-wire arc spraying (TWAS) is promising for on-site proactive maintenance. In this paper, FeCr-based coating was prepared on AISI 1020 carbon steel substrate by TWAS. The coating microstructure was characterized in terms of porosity, oxides and constituent phases. The wear behavior of the coating was evaluated by ball-on-disk wear test at both room temperature (RT) and tube service temperature of 300 °C. The results show that the coating is characterized with composite-like structure of oxide boundaries and FeCr solid solution, with hard phase of borides embedded within FeCr phase, resulting an average microhardness of 10.80 GPa. Tested at RT and 300 °C, the weight loss of the coating indicates much better wear resistance than substrate steel. The morphology of the wear scars demonstrates that the wear mechanism of the coating transformed from furrow and fracture spalling at RT to adhesive and abrasive wear at high temperature. The high hardness and low oxidation rate of the coating contribute to excellent wear resistant. The FeCr-based coating by on-site TWAS has been successfully applied on boiler tubes, large-sized blades of slurry pumps and various fans.

中文翻译：

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现场双丝电弧喷涂铁铬基涂层用于电厂部件的主动维护

对发电厂损坏的机械部件进行翻新的需求很高。双丝电弧喷涂 (TWAS) 有望用于现场主动维护。本文采用 TWAS 在 AISI 1020 碳钢基体上制备了 FeCr 基涂层。涂层微观结构的特征在于孔隙率、氧化物和组成相。通过在室温 (RT) 和 300 °C 的管道使用温度下的球盘磨损试验来评估涂层的磨损行为。结果表明，涂​​层具有氧化物界面和FeCr固溶体的复合结构，硼化物硬质相嵌入FeCr相内，平均显微硬度为10.80 GPa。在室温和 300 °C 下进行测试，涂层的重量损失表明耐磨性比基材钢好得多。磨痕的形态表明涂层的磨损机制从室温下的沟纹和断裂剥落转变为高温下的粘着磨损和磨粒磨损。涂层的高硬度和低氧化率有助于优异的耐磨性。现场TWAS的FeCr基涂层已成功应用于锅炉管、大型渣浆泵叶片和各种风机。