核电站安全端异种金属焊缝超声检查技术

Review of Research on Ultrasonic Examination Technology of Safe-end Dissimilar Metal Weld of NPP

安全端异种金属焊缝在寿命期内的结构完整性对于核电站的安全运行来说是至关重要的。奥氏体粗晶材料的存在以及焊缝几何结构的复杂性使得异种金属焊缝的检查非常具有挑战性。概述了核电站异种金属焊缝超声检查相关的内容,包括检查的技术要求、国际检查技术特点、检查技术的局限性、针对缺陷检查的可靠性以及检查资格认证等方面。国际上开展的系列理论和实验研究表明,针对异种金属焊缝检查的可靠性有待继续提高,对焊缝和预堆边材料中缺陷的准确检查和可靠评价目前还存在一定困难,需要在新方法和新技术的应用方面继续进行深入研究。

The structural integrity of safe end dissimilar metal weld {DMW） during the lifetime is of significance to the safety operation of nuclear power plant. The austenitic coarse grain material and complex geometry configuration of DMW weld make the examination of dissimilar metal weld very challenging. In this paper the ultrasonic examination technique of dissimilar metal weld is reviewed and summarized, including code inspection requirement, technique characteristic of the abroad vendor, limitation of inspection technique, reliability and inspection qualification etc. The series of theoretical and experimental research showed that the inspection reliability of dissimilar metal weld could be improved continually and it seems a little difficult for accurate examination and reliable evaluation for defect located at position between the weld and buttering, which require further thorough theoretical research and application of new method and technique.