摘要
针对某火电厂锅炉水冷壁管局部开裂鼓包导致泄漏的情况,通过化学成分分析、金相组织、维氏硬度、扫描电镜及能谱分析等试验方法,对水冷壁管进行取样分析。结果表明:炉水局部浓缩产生酸性环境,使水冷壁管内壁受到腐蚀,引起内部脱碳,并在内壁处产生微裂纹,造成氢损伤,是导致水冷壁管开裂及鼓包的主要原因;Cl~–对水冷壁管内壁也有一定的腐蚀作用,造成管壁减薄;水冷壁管局部过热导致该区域外壁组织老化,即珠光体球化,但这并未对管样的力学性能产生严重影响。
Against the leakage caused by local cracking drum of boiler water wall tubes in a thermal power plant, several test methods such as chemical composition analysis, metallurgical structure analysis, Vickers hardness analysis, scanning electron microscopy and energy spectrum analysis were carried out to find out the reasons. The results show that, under the acid conditions resulted from localized concentration of boiler water, the inner wall of the water wall tube is corroded, causing inner decarburization and micro crack on the inner wall. Such hydrogen damage results in cracking drum of the boiler tube. Moreover, Cl^- has a certain corrosion effect on the waterwall’s inner wall, which causes thinning of the tube wall. In addition, local overheating of the water wall tube results in aging of the outer wall, namely spheroidization of the pearlite, but this does not have a serious influence on mechanical properties of the tubes.
作者
张冰清
田进
张志博
吴术全
江峰
ZHANG Bingqing;TIAN Jin;ZHANG Zhibo;WU Shuquan;JIANG Feng(State Key Laboratory for Mechanical Behavior of Materials,Xi’an Jiaotong University,Xi’an 710049,China;Xi’an Thermal Power Research Institute Co.,Ltd.,Xi’an 710054,China)
出处
《热力发电》
CAS
北大核心
2019年第5期97-101,共5页
Thermal Power Generation
关键词
锅炉
水冷壁
氢损伤
脱碳
微裂纹
腐蚀
局部过热
boiler
water wall
hydrogen damage
decarburization
micro crack
corrosion
local overheating
