火力发电机组锅炉水冷壁管开裂原因分析

Analysis on Cracking Reason of Water Wall Tube for Thermal Power Plant Boiler

通过宏观检查、力学性能测试、金相组织检验及扫描电镜等方法,分析了某火力发电机组锅炉水冷壁管喷涂部位的开裂原因。结果表明:该水冷壁管喷涂材料选择、喷涂工艺控制是导致此次开裂失效的主要原因,该裂纹的存在会显著降低水冷壁管管材的力学性能,影响机组的可靠运行。该结果对今后火电机组锅炉受热面管的热喷涂工艺改进具有较大的指导意义。

The cracking reason for water-wall tube with thermal spraying of a thermal power plant boiler was studied through macroscopic examination, microstructure, mechanical properties test and SEM spectrum analysis. Results show that the water-wall tube coating material selection, spraying process controlling will be the main cause for this failure, the mechanical performance of tube is reduced significantly because of the existence of cracks and the reliability of unit operation will be affected. This result is of great significance for improvement of plant boiler thermal spraying process in future.