摘要
采用实验和仿真模拟相结合的方法研究了不锈钢/铝合金激光-MIG复合熔钎焊接头电偶腐蚀行为。利用常规电化学方法和微区电化学方法(扫描开尔文探针SKP和局部电化学交流阻抗LEIS)研究了接头的腐蚀行为。采用大型仿真软件COMSOL Multiphysics建立了钢/铝异种熔钎焊接接头的腐蚀模型,用电化学方法估算了母材在中性3.5%NaCl溶液中的交换电流密度,并作为模拟的边界条件。结果发现,钢/铝异种金属熔钎焊接接头的耐蚀性较母材低,且其抗腐蚀性能随着溶液pH值的下降而降低。模拟结果与实验结果一致,焊缝电位介于两种母材之间,铝侧金属的电位低作为阳极发生腐蚀,界面金属间化合物IMC与铝焊缝交界处优先发生腐蚀。
The galvanic corrosion behavior of a laser-MIG hybrid welding-brazing joint of 6061 aluminium alloy to SUS304 stainless steel was studied by combining experiment and simulation.The corrosion behavior of the joint was researched by conventional electrochemical method and micro area electrochemical methods(scanning Kelvin probe system,SKP and localized electrochemical impedance spectroscopy,LEIS).The large-scale simulation software COMSOL Multiphysics was used,and a corrosion simulation model for the galvanic couple of stainless steel/Al-alloy welded joint was established,the exchange current density of the base metals in neutral 3.5%NaCl solution was estimated by electrochemical polarisation,which was used as the boundary conditions in the simulation.The results show that the corrosion resistance of steel/aluminum dissimilar metal welding-brazed joint is lower than that of base metals,and its corrosion resistance decreases with the decrease of solution pH value.The simulation results are consistent with the experimental results,the weld potential is between that of the two base metals.The potential of the metal at the aluminum side is lower,which is used as the anode for corrosion,and the corrosion occurs preferentially at the interface between intermetallic compound(IMC)and aluminum weld.
作者
杨红伟
王鑫
付浩
刘瑞琳
朱宗涛
YANG Hongwei;WANG Xin;FU Hao;LIU Ruilin;ZHU Zongtao(CRRC Nanjing Puzhen Co.,Ltd.,Nanjing 210031,China;Key Laboratory of Advanced Technologies of Materials,Ministry of Education,School of Materials Science and Engineering,Southwest Jiaotong University,Chengdu 610031,China)
出处
《热加工工艺》
北大核心
2023年第9期123-129,共7页
Hot Working Technology
基金
四川省重点研发计划(重大科技专项)项目(2022YFG0086)。
关键词
异种金属
熔钎焊
电偶腐蚀
dissimilar metals
welding brazing
galvanic corrosion
