火电厂锅炉20G水冷壁管失效分析  

Failure Analysis on 20G Water Wall Tube of Boiler in Thermal Power Plant

作　　者：张仁珊 刘宇[2] 任耀剑[2] 杨春敏[3] ZHANG Renshan;LIU Yu;REN Yaojian;YANG Chunmin(China Energy Zhejiang Ninghai Power Generation Company Limited,Ningbo 315612,China;School of Materials and Physics,China University of Mining and Technology,Xuzhou 221116,China;School of Low Carbon Energy and Power Engineering,China University of Mining and Technology,Xuzhou 221116,China)

机构地区：[1]国能浙江宁海发电有限公司,浙江宁波315612 [2]中国矿业大学材料与物理学院,江苏徐州221116 [3]中国矿业大学低碳能源与动力工程学院,江苏徐州221116

出　　处：《热加工工艺》2024年第2期78-81,共4页Hot Working Technology

基　　金：中央高校基本科研业务费专项资金项目(2020ZDPYMS38)。

摘　　要：通过宏观分析、显微组织观察、室温拉伸性能试验、物相分析和成分分析,对某火电厂锅炉20G水冷壁管爆管原因进行分析。结果表明:开裂起源于水冷壁管内壁,爆口及爆口附近壁厚存在明显的腐蚀减薄现象,爆口附近内壁显微组织为铁素体和珠光体,珠光体存在球化现象,沿晶界出现裂纹和氧化物。结合锅炉运行状况,推测水冷壁管在接焊缝两侧积垢聚集区产生局部氧腐蚀和氢腐蚀,是引起爆裂的主要原因。建议控制水质,做好停炉保护工作,减少炉管积垢,加强焊缝连接处壁厚的检测,及时更换不满足厚度要求的管路。The causes of 20G water wall tube explosion of boiler in a thermal power plant were analyzed through macro analysis,microstructure observation,room temperature tensile property test,phase and composition analysis.The results show that the cracking originates from the inner wall of water wall tube.There is obvious corrosion thinning in the wall thickness at and near the burst.The microstructure of the inner wall near the burst is ferrite and pearlite,pearlite generates spheroidization,and the cracks and oxides appear along the grain boundary.Combined with the operating conditions of the boiler,it is speculated that the water wall tube produces local oxygen corrosion and hydrogen corrosion in the crud accumulation area on both sides of the welding seam.It is suggested to control the water quality,take protective measures during boiler shutdown,reduce the scale of furnace pipe,carry out wall thickness inspection of welded joint and replace the pipeline that does not meet the thickness requirements in time.

关 键 词：水冷壁 失效分析 20G 氧腐蚀 显微组织 

分 类 号：TG111.91[金属学及工艺—物理冶金]