核电厂焊接OVERALY技术标准分析

Study and Discussion on Weld OVERALY Technical Standards for Nuclear Power Plants

焊接OVERLAY技术是通过在原设计壁厚基础上增加耐蚀材料,改变原壁厚内表面的应力状态,从而抑制裂纹的产生或扩展,可用于在役维修或预防性维修。该技术在国外有着广泛的应用,在国内反应堆控制棒驱动机构(CRDM)修复上也有局部应用案例,但国内对此技术缺乏系统、完整的研究,制约了该技术的推广。文中通过ASME标准和文献研究,系统地梳理了焊接OVERLAY技术的分类,比较分析了几种技术的适用范围和特点。介绍了ASME-Ⅺ卷(2005年补遗)非强制性附录Q"1、2、3级奥氏体不锈钢管道焊接件的堆焊修复",总结了标准演化过程,并对其关键标准条款进行了探讨,为焊接OVERLAY技术的国内推广和标准规范的制定提供了技术支撑。

Weld OVERLAY technology is to add corrosion-resistant materials on the basis of the original design wall thickness to change the stress state of the original inner surface, thereby inhibiting the generation or expansion of cracks. It can be used for in-service maintenance or preventive maintenance. The technology is widely used abroad, and has some application cases of CRDM repairing in China. However, the lack of systematic and complete technical research restricts the popularization of the technology. This article systematically sorts out the classification and standard evolution of Weld OVERLAY technology, compares and analyzes the application scope and characteristics by ASME standards and literature studying. This article introduces the Non mandatory Appendix Q of ASME BPVC.XI-2005, Weld Overlay Repair of Classes 1, 2, and 3 Austenitic Stainless Steel Piping Weldments, summarizes the evolution process, analyzes the key standard clauses, and provides technical support for the promotion of this technology and the formulation of standards.