在奥氏体不锈钢制再沸器的上管板与壳程筒体焊接的管板一侧发生蒸气泄漏。采用化学成分分析、力学性能测定、宏、微观检验、有限元应力计算及振动测试等方法对再沸器的材料、加工工艺和工作状况进行了综合分析。结果表明,管板材料性能较差,在制造该再沸器过程中受焊接热循环和较高应力水平的影响,造成在热影响区形成微裂纹,进而又在工作介质和应力的作用下在该区域发生疲劳损伤而形成宏、微观裂纹致蒸气泄漏。提出了预防和改进措施。

The steam leakage was occurred on the welding zone of the tube sheet of the austenitic stainless steel heat exchanger. By means of the chemical composition analysis,mechanical property testing and macro-microstructure examination,EFM calculation and vibration testing,materials and working process are analyzed comprehensitly. In order to prevent and avoid the fatigue failure,some measure and suggestion have been proposed. And the failure analysis method mentioned will be helpful to the analysis works of anstenitic stainless steel vessels′ failure.