Stress-corrosion behavior and characteristics of the friction stir welding of an AA2198-T34 alloy
来源期刊：International Journal of Minerals Metallurgy and Materials2020年第6期
论文作者：Quan-qing Zeng Song-sheng Zeng Dong-yao Wang
文章页码：774 - 782
摘 要：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.
Quan-qing Zeng1,2，Song-sheng Zeng1,3，Dong-yao Wang1,2
1. Research Institute of Light Alloy, Central South University2. Key Laboratory of the Ministry of Education of Nonferrous Metals, Central South University3. Technology Center, Valin Arcelor Mittal Automotive Steel Co., Ltd.
摘 要：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.
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