某热电厂锅炉水冷壁泄漏失效分析  

Failure Analysis of Boiler Water Wall Leakage of a Thermal Power Plant

作　　者：师学礼 唐文宇 郭宇航[2] 张禹 SHI Xueli;TANG Wenyu;GUO Yuhang;ZHANG Yu(CHN Energy Jiangsu Electric Engineering Technology Co.,Ltd.,Zhenjiang 212006,China;School of Materials Science and Engineering,Jiangsu University of Science and Technology,Zhenjiang 212003,China;CHN Energy Jiangsu Jianbi Power Co.,Ltd.,Zhenjiang 212006,China)

机构地区：[1]国能江苏电力工程技术有限公司,江苏镇江212006 [2]江苏科技大学材料科学与工程学院,江苏镇江212003 [3]国能江苏谏壁发电有限公司,江苏镇江212006

出　　处：《新技术新工艺》2024年第4期64-69,共6页New Technology & New Process

基　　金：江苏科技大学博士科研启动基金资助项目(1062932101);江苏省产学研合作项目(BY2021522)。

摘　　要：通过宏观分析、显微组织观察,对某热电厂锅炉水冷壁管内部组织、表面裂纹形貌与分布情况等进行分析,探究水冷壁管发生爆管泄漏的原因。结果表明:开裂起源于水冷壁管内壁,漏点及漏点附近壁厚存在明显的冲刷减薄现象,最薄处仅有320.14μm;漏点附近内壁的显微组织为铁素体+珠光体+少量碳化物,沿晶界出现细小的层片状裂纹和氧化物。结合锅炉运行状况,推测水冷壁管弯曲面存在一定原始缺陷,高温高压导致的缺陷不断扩展是引起爆裂的主要原因。建议加强对水冷壁存在大角度折弯部位管道的表面检查,及时更换不满足要求的管线。Through macroscopic analysis and microstructure observation,the internal structure,surface crack morphology and distribution of the water wall tube of a thermal power plant boiler were analyzed,and the causes of the leakage of the water wall tube were explored.The results showed that the crack originated from the inner wall of the water wall tube,and there was obvious erosion thinning phenomenon of the wall thickness in the leakage point and near the leakage point,and the thinnest part was only 320.14μm.The microstructure of the inner wall near the leakage point was ferrite+pearlite+a small amount of carbide,and fine lamellar cracks and oxides appeared along the grain boundary.Combined with the operation status of the boiler,it was speculated that there were some original defects in the bending surface of the water wall tube,and the continuous expansion of the defects caused by high temperature and high pressure was the main cause of the burst.It was recommended that strengthening the surface inspection of the pipes with large angle bending parts of the water wall and replacing the pipes that did not meet the requirements in time.

关 键 词：水冷壁 失效分析 显微组织 裂纹 高温高压 泄漏 

分 类 号：TG157[金属学及工艺—热处理] TG179[金属学及工艺—金属学]