10钢换热器管泄漏分析

Analysis on 10 Steel Heat Exchanger Tube Leaking

一外径为25mm、壁厚2.5mm的10钢换热器管在使用中发生蒸汽泄漏。对泄漏的换热器管进行了宏观分析、化学成分检测、金相检验和能谱分析。结果表明:换热器管化学成分符合要求,但腐蚀严重,氧化层较厚且致密,靠近基体的氧化物中氧含量最高。可以断定,换热器管的泄漏主要是由于轧制过程中氧化皮被压入内表面并被严重腐蚀而穿孔所致。提出了相应的改进措施和建议。

It was found that a 10 steel heat exchanger tube 25 mm in OD by 2.5 mm wall thickness had leaked steam in service.The failed tube was subjected to macro-check,chemical composition analysis,metallographic examination and EDS analysis.The results showed that the tube had composition which conforms with the requirement but was corroded seriously,and that had thicker and compact oxide layer in which oxygen content was maximum value in area adjacent to the substrate.It may be concluded that leakage of the heat exchanger tube is mainly attributed to oxide scale being pressed into its inner surface during the rolling and its being severely corroded and therefore perforated.Some improvement measures and suggestions were put forward.