二次过热器炉管的腐蚀损伤分析与表征

CORROSIVE DAMAGE ANALYSIS AND CHARACTERIZATION OF BOILER TUBES IN A SECONDARY SUPERHEATER

采用金相检验、扫描电镜、三维视频系统及能谱分析等方法,对350MW火力发电机组经13万h运行后二次过热器炉管内表面严重腐蚀损伤进行了检测与表征。结果表明,该炉管内表面的损伤主要是由水中的氯离子及溶解氧作用下引起的点腐蚀所致,为此提出了相应的预防措施。

Examination and characterization for the serious corrosive damage of inner surface of boiler tubes in a secondary superheater, which had been in service for 130000 hours in a 350MW power generator, were carried out with the help of metallography, scanning electron microscopy, 3-D digital video microscopy and energy dispersive analysis. It was shown that the damage of the inner surface of the tubes was mainly caused by pitting corrosion, which was attributed to chloride ions and dissolved oxygen in water. And the corresponding proposals were put forward to prevent the tubes from pitting corrosion and subsequent leakage.