稳压器接管安全端堆焊结构裂纹扩展计算分析

Crack Propagation Analysis of Weld Overlay Structure for Pressurizer Nozzle Safety End

针对核电厂稳压器接管安全端堆焊设计结构,按照稳压器设计载荷,对假设的安全端焊接区域的裂纹开展疲劳和应力腐蚀引起的裂纹扩展分析,获得裂纹扩展尺寸,并进行安全评估,结果表明,异种金属焊缝区域在周期末的最大环向裂纹深度扩展量为0.4×10-3 mm,最大轴向裂纹深度扩展量为23.6×10-3 mm;不锈钢焊缝区域在周期末的最大环向裂纹深度扩展量为12.4×10-3 mm,最大轴向裂纹深度扩展量为0,裂纹扩展量均满足堆焊设计要求,为稳压器接管安全端堆焊结构设计和评定提供参考。

Based on the design loads of the pressurizer in nuclear power plants,this paper investigates the crack propagation induced by the fatigue and the stress corrosion of the design overlay weld structure in the pressurizer nozzle safety end.The crack propagation depth is obtained,and the safety assessment is carried out.At the end of the cycle,the maximum circumferential crack growth depth and axial crack growth depth in dissimilar metal weld zone are 0.4×10-3 mm and 23.6×10-3 mm,respectively,while the maximum circumferential crack growth depth and axial crack growth depth in stainless steel weld zone are 12.4×10-3 mm and 0 mm.The results show that the crack propagation meets the design requirement.This analysis can provide a reference for the overlay weld structure design and evaluation of the pressurizer nozzle safety end.