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采用氯化钠+过氧化氢溶液浸泡试验研究AA6061-T6铝合金搅拌摩擦焊搭接接头的腐蚀行为。采用循环动电位极化测试、扫描电子显微镜和能谱仪表征腐蚀形貌，揭示焊接区与基体合金的腐蚀机理。研究了焊接接头的显微组织和剪切强度。结果表明，与基体合金相比，焊接区在腐蚀溶液中会发生晶间腐蚀和点蚀。搭接剪切测试结果表明，所得焊接接头的拉伸剪切强度为128 MPa,超过基体合金强度的60%。电化学测试结果表明，焊核区和热影响区的保护电位比点蚀电位更负，说明焊核区与热影响区点蚀的趋势不强。基体合金抗腐蚀性比焊缝区的强，而热影响区的抗腐蚀性最差。点蚀主要源于金属间化合物边缘，因为与铝基体相比，金属间化合物的自腐蚀电位更高而成为阴极。由于焊缝区的金属间化合物增加，腐蚀电偶增加，焊缝的抗腐蚀性降低。

Corrosion behavior of friction stir lap welded AA6061-T6 aluminum alloy was investigated by immersion tests in sodium chloride + hydrogen peroxide solution. Electrochemical measurement by cyclic potentiodynamic polarization, scanning electron microscopy, and energy dispersive spectroscopy were employed to characterize corrosion morphology and to realize corrosion mechanism of weld regions as opposed to the parent alloy. The microstructure and shear strength of welded joint were fully investigated. The results indicate that, compared with the parent alloy, the weld regions are susceptible to intergranular and pitting attacks in the test solution during immersion time. The obtained results of lap shear testing disclose that tensile shear strength of the welds is 128 MPa which is more than 60% of the strength of parent alloy in lap shear testing. Electrochemical results show that the protection potentials of the WNZ and HAZ regions are more negative than the pitting potential. This means that the WNZ and HAZ regions do not show more tendencies to pitting corrosion. Corrosion resistance of parent alloy is higher than that for the weldments, and the lowest corrosion resistance is related to the heat affected zone. The pitting attacks originate from the edge of intermetallic particles as the cathode compared with the Al matrix due to their high self-corrosion potential. It is supposed that by increasing intermetallic particle distributed throughout the matrix of weld regions, the galvanic corrosion couples are increased, and hence decrease the corrosion resistance of weld regions.