Abstract The surface residual stress as well as corrosion behavior of an Al-Zn-Mg-Cu alloy plate is investigated under various pre-deformation conditions via X-ray diffraction, transmission electron microscopy, laser scanning microscope, open circuit potentials and electrochemical impedance spectroscopy measurements. Results reveal that the major extent of residual stresses from quenching can be relieved by 2% pre-strain, while the surface residual stress condition transforms from compression to tension if pre-strain exceeds 4%. During aging, the dislocations introduced by pre-strain promote the nucleation of large η phase and accelerate the coarsening of η′ precipitates. With increasing the pre-strain level, the number density of coarse η phase both at grain boundary and within matrix increases, resulting in a decrease in the corrosion resistance. In addition, the immersion test reveals an acceleration of corrosion when tensile residual stress exists in the surface of plate.

中文翻译：

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预应变对Al-Zn-Mg-Cu合金板表面残余应力和腐蚀行为的影响

摘要 通过X射线衍射、透射电子显微镜、激光扫描显微镜、开路电位和电化学阻抗谱研究了Al-Zn-Mg-Cu合金板在不同预变形条件下的表面残余应力和腐蚀行为。测量。结果表明，淬火残余应力的主要程度可以通过2%的预应变消除，而如果预应变超过4%，表面残余应力状态由压缩转变为拉伸。在时效过程中，预应变引入的位错促进了大 η 相的形核并加速了 η' 相的粗化。随着预应变水平的增加，晶界和基体内粗大η相的数量密度增加，导致耐腐蚀性能下降。