焊缝余高对铜镍合金管材腐蚀行为的影响  

Influence of weld reinforcements on corrosion behavior of Cu-Ni alloy pipe

作　　者：张威[1,2] 刘峰 李相波 程旭东 苏艳[3] 邵刚勤[1] ZHANG Wei;LIU Feng;LI Xiangbo;CHENG Xudong;SU Yan;SHAO Gangqin(State Laboratory of Advanced Technology for Materials Synthesis and Processing,Wuhan University of Technology,Wuhan 430070,China;State Key Laboratory for Marine Corrosion and Protection,Qingdao 266101,China;Southwest Technology and Engineering Research Institute,Chongqing 400039,China)

机构地区：[1]武汉理工大学材料复合新技术国家重点实验室,武汉430070 [2]中国船舶集团公司第七二五所海洋腐蚀与防护重点实验室,青岛266101 [3]西南技术工程研究所,重庆400039

出　　处：《焊接学报》2023年第1期115-121,I0009,I0010,共9页Transactions of The China Welding Institution

基　　金：西南技术工程研究所合作基金项目(HDHDW5902020101)。

摘　　要：海水管道焊缝下游区是发生腐蚀的热点区域.为探究B30管道焊缝余高对与其下游区腐蚀行为的影响,利用原位电化学测试装置和自制循环海水冲刷装置,在3天、7天、15天、30天4个冲刷节点进行试验.测试了3种模拟焊缝余高(0 mm;0.5 mm;1.5 mm)在紧邻热影响区和下游30 mm处母材区的电化学阻抗谱,用扫描电镜观察了试样表面的腐蚀形貌,结合COMSOL软件建立了有限元仿真流态模型,探讨了余高对介质流态的影响.结果表明,在有焊缝情况下,热影响区和母材区阻抗值均小于无焊缝结构,焊缝结构会加速下游区的腐蚀,且余高越大,腐蚀倾向也越大;热影响区腐蚀速率均大于母材区;流态模型显示出在热影响区位置出现了涡流,涡流加速了热影响区的腐蚀.The downstream area of seawater pipeline welds is a hot spot for corrosion.In order to explore the influence of weld reinforcements on the corrosion behavior of B30 pipes in the downstream area,the in-situ electrochemical testing device and the home-made circulating seawater-scouring device were used in four scouring-test nodes at 3 d,7 d,15 d,30 d.The impedance spectra were tested with three simulated weld reinforcements(0 mm;0.5 mm;1.5 mm)in the adjacent heat-affected zone(HAZ)and 30-mm-downstream base-metal zone(BMZ).The corrosion morphology of the sample surface was observed by the scanning electron microscope(SEM),and the finite-element-simulation flow-model was established by using COMSOL software.The influence of weld reinforcements on the flow state of the medium was discussed.Results show that the impedance values in the HAZ and BMZ were smaller than those of the no-welding in the case of welding.The weld structure would accelerate the corrosion in the downstream zone.The larger the reinforcement,the greater the corrosion tendency.The corrosion rate in the HAZ was larger than that in the BMZ.The flow model showed that an eddy current appeared in the HAZ and accelerated the corrosion there.

关 键 词：B30焊缝 热影响区 母材区 电化学腐蚀 有限元仿真 

分 类 号：TG405[金属学及工艺—焊接] TG174.3