摘要
某电厂热网加热器不锈钢换热管使用1年半即发生开裂泄漏。通过对开裂管样进行宏观检验、化学成分分析、金相组织分析、电镜及能谱分析,认为其主要由不锈钢的应力腐蚀所致。对此,建议严格控制热网水中的Cl-、溶解氧、硬度等指标;在加热器停运后,立即采用除盐水冲洗以降低管内壁的Cl-浓度,并将换热管充水保护改为充氮保护。
The stainless steel heat exchange tube in a heating network was cracked and leakage happened only after one and a half year's operation.Based on a series of tests on the cracked pipe,such as macroscopic examination,chemical composition analysis,metallographic analysis,electron microscopic and energy spectrum analysis,stress corrosion cracking was considered as the main reason for tube leakage.Thus,to prevent the heat exchange tube from cracking,it is suggested that indexes like Cl-concentration,dissolved oxygen content and the water hardness of the heating network should be strictly controlled;the heat exchange tube should be washed by using demineralized water as soon as the heater stopped working,so as to decrease the Cl-concentration inside the pipe wall;the tube should be protected by filling with nitrogen instead of water.
出处
《热力发电》
CAS
北大核心
2012年第10期75-77,共3页
Thermal Power Generation
关键词
热网
加热器
不锈钢管
氯离子
应力腐蚀
heating network
heater
stainless steel tube
chloride ion
stress corrosion
