摘要
Abstract
This paper presents a systematic failure analysis and structural optimization study addressing the rectifier plate fracture incident observed during factory acceptance testing of the residual heat removal(RHR)pump for the domestically developed"Hualong One"nuclear power plant.Through fracture surface analysis,welding process review,stress level test-ing,and finite element simulation,the failure was attributed to the irrational structural design of the single cantilevered recti-fier plate,which induced stress concentration in the weld zone.Under transient flow regulation conditions,the maximum stress at the weld toe of the rectifier plate reached 197.77MPa,exceeding the fatigue limit of 94 MPa for austenitic stainless steel specified in the design standard,triggering low-cycle high-stress fatigue fracture.To resolve this issue,an optimized dual-symmetric rectifier plate design was implemented:the radial length of each plate was reduced to half of the original di-mension,the axial length was shortened to 120 mm,and the welded joint was modified to a full-penetration structure.Post-optimization analysis showed that the dynamic stress amplitude of the rectifier plate decreased by over 82%,with the maxi-mum transient stress at the weld toe reduced to 21.1MPa,significantly below the fatigue limit.Following a 200-hour endur-ance test,the optimized rectifier plate passed non-destructive testing(NDT),exhibited stable operational parameters,and met nuclear safety equipment requirements.This research not only ensured project delivery timelines but also provided cru-cial empirical data and engineering insights to support the localized design of critical nuclear power equipment.关键词
余热排出泵/整流板/焊接结构/疲劳断裂/核电设备国产化Key words
residual heat removal pump/rectifier plate/welded structure/fatigue fracture/localization of nuclear power equipment分类
矿业与冶金
