某石油注汽锅炉水冷壁管20G钢的泄漏原因分析  

Leakage Cause Analysis on 20G Steel Tube of Boiler Water Wall in Oilfield

作　　者：田晓[1] 秦承鹏[1] 徐慧 梁碧珂 商雪威 TIAN Xiao;QIN Chengpeng;XU Hui;LIANG Bike;SHANG Xuewei(Xi'an Thermal Power Research Institute,Xi'an 710051,China;Xi'an YiTong Thermal Technology Service Co.,Ltd.,Xi'an 710054,China)

机构地区：[1]西安热工研究院有限公司,陕西西安710051 [2]西安益通热工技术服务有限责任公司,陕西西安710054

出　　处：《热加工工艺》2021年第2期159-163,共5页Hot Working Technology

基　　金：华能国际电力股份有限公司资助项目(TQ-18-HJK13)。

摘　　要：某石油注汽锅炉在生产作业中发生水冷壁管线爆管泄漏。为查明水冷壁的泄漏原因,对泄漏管段进行了化学成分分析、力学性能测试、显微组织分析和扫描电镜及能谱分析。结果表明,泄漏管段向火面壁厚减薄严重,且存在内壁麻坑、微裂纹以及非金属夹杂物超标等原始制造缺陷;其内部高温汽水介质中含有微量的Cl^(-)、S^(2-),运行一段时间后,向火面缺陷部位优先发生腐蚀溶解而造成管壁不断减薄,最终,管子因剩余壁厚不能满足强度要求而发生爆管。A water-wall tube of a steam injection boiler suddenly leaks in production. In order to find out the leakage cause, the leakage tube-section was tesetd by chemical composition analysis, mechanical properties testing, microstructure testing, SEM & EDS. The results show that the wall thickness of leakage tube-section severely reduces on the fire side, and there are original manufacturing defects such as pits, microcracks and non-metallic inclusions exceeding standards in the inner wall. The high temperature steam-water substance inside the leakage tube contains Cl-and S2-. After running for a period of time, the corrosion dissolution of the defect areas in tube fire-exposed surface occurs preferentially, resulting in continuous thinning of the tube wall, and finally the tube bursts due to the residual wall thickness dissatisfing the strengthen requirement.

关 键 词：20G钢 壁厚减薄 内壁麻坑 非金属夹杂 制造缺陷 

分 类 号：TG172.2[金属学及工艺—金属表面处理]