调峰机组水冷壁管焊缝背火侧开裂原因分析  

Cracking Cause Analysis for Weld of Back Fire Side of Water Wall Tube in Variable Load Unit

作　　者：郑坊平[1] 张红军[1] 林琳[1] 宋少平[1] ZHENG Fangping;ZHANG Hongjun;LIN Lin;SONG Shaoping(Thermal Power Research Institute,Xi'an 710032,China)

机构地区：[1]西安热工研究院有限公司,陕西西安710032

出　　处：《热加工工艺》2020年第19期154-157,153,共5页Hot Working Technology

摘　　要：通过对锅炉的运行、检修情况的调查及水冷壁开裂管样的理化性能试验分析,对某厂调峰机组水冷壁管焊缝背火侧的开裂原因进行了分析。结果表明:水冷壁管焊缝背火侧纵向开裂性质为疲劳开裂。存在硬度超标和根部凸出超标的水冷壁管环焊缝,在深度调峰期频繁超温引起的交变应力作用下逐渐在热应力最大的环焊缝背火侧中部内壁萌生纵向疲劳裂纹,直至开裂泄漏。The cracking cause for the weld of back fire side of water wall tube in variable load unit of a factory was analyzed by investigation on operation and maintenance of boiler and physical and chemical property test analysis of water wall cracked tube sample. The results show that the cracking property of weld of back fire side of the water wall tube is fatigue cracking. In the case of the water wall tube girth joint with the hardness and root protrusion exceeding the standard, under the alternating stress caused by frequent over-temperature during deep peak shaving period, the longitudinal fatigue crack is initiated in the middle inner wall of the back-fire side of the girth joint with the highest thermal stress, then the crack causes leakage.

关 键 词：调峰机组 水冷壁管 焊缝开裂 疲劳 交变应力 

分 类 号：TG111.91[金属学及工艺—物理冶金]