薄壁不锈钢管道的泄漏分析与检测

Leakage analysis and detection of thin-walled stainless steel tubes

对某电厂存在介质泄漏的薄壁不锈钢管道进行了理化检验,结合晶间腐蚀试验、垢样XRD分析、微观组织检验及漏点分析等方法对泄漏原因进行了分析,结果表明是管子内残留水(工业水)引起的点蚀穿孔导致了泄漏;针对点蚀特征,设计开发了相应的相控阵超声检测工艺,并采用相控阵超声横波自聚焦换能器对焊接接头处点蚀类缺陷进行了检测。试验结果表明,该工艺可有效检出样管处的典型点蚀缺陷,检测高效,结果直观。

A physical and chemical inspection was conducted on a thin-walled stainless steel pipeline with medium leakage in one power plant.The cause of the leakage was analyzed using methods such as intergranular corrosion test,scale sample XRD analysis,microstructure inspection,and leakage point analysis.The results showed that the leakage was caused by pitting corrosion perforation caused by residual water(industrial water)in the pipeline.Based on the characteristics of pitting corrosion,a corresponding phased array ultrasonic testing process was designed and developed,and an ultrasonic phased array transverse wave self focusing transducer was used to detect pitting corrosion defects at welded joints.The experimental results showed that this process can effectively detect typical pitting corrosion defects at the tube sample,with efficient detection and intuitive results.