To better understand the stress-corrosion behavior of friction stir welding (FSW), the effects of the microstructure on the stress-corrosion behavior of the FSW in a 2198-T34 aluminum alloy were investigated. The experimental results show that the low-angle grain boundary (LABs) of the stir zone (SZ) of FSW is significantly less than that of heated affected zone (HAZ), thermo-mechanically affected zone (TMAZ), and parent materials (PM), but the grain boundary precipitates (GBPs) T1 (Al₂CuLi) were less, which has a slight effect on the stress corrosion. The dislocation density in SZ was greater than that in other regions. The residual stress in SZ was +67 MPa, which is greater than that in the TMAZ. The residual stress in the HAZ and PM is −8 MPa and −32 MPa, respectively, and both compressive stresses. The corrosion potential in SZ is obviously less than that in other regions. However, micro-cracks were formed in the SZ at low strain rate, which indicates that the grain boundary characters and GBPs have no significant effect on the crack initiation in the stress-corrosion process of the AA2198-T34. Nevertheless, the residual tensile stress has significant effect on the crack initiation during the stress-corrosion process.

为了更好地理解搅拌摩擦焊（FSW）的应力腐蚀行为，研究了微观结构对2198-T34铝合金中FSW的应力腐蚀行为的影响。实验结果表明，FSW搅拌区（SZ）的低角度晶界（LABs）显着小于受热影响区（HAZ），热机械影响区（TMAZ）和母材（PM） ），但晶界析出（GBPs）T1（Al ₂CuLi）少，对应力腐蚀影响很小。深圳的位错密度大于其他地区。SZ中的残余应力为+67 MPa，大于TMAZ中的残余应力。HAZ和PM中的残余应力分别为-8 MPa和-32 MPa，并且均为压缩应力。深圳的腐蚀潜力明显小于其他地区。然而，在低应变率下在深圳形成微裂纹，这表明在AA2198-T34的应力腐蚀过程中，晶界特征和GBPs对裂纹萌生没有显着影响。然而，残余拉应力在应力腐蚀过程中对裂纹萌生有重大影响。