Microstructure characteristics and corrosion behavior of metal inert gas welded dissimilar joints of 6005A modified by Sc and 5083 alloys  

Sc改性的6005A和5083铝合金惰性气体保护焊异种接头的显微组织特征和腐蚀行为

作　　者：Guo-fu XU Liang LIU Ying DENG Yu ZENG Jun-chang CAO Lei TANG Xiao-yan PENG Jia-qi DUAN Mei-chan LIANG Qing-lin PAN 徐国富;刘亮;邓英;曾渝;曹俊昌;唐磊;彭小燕;段佳琦;梁美婵;潘清林(中南大学材料科学与工程学院,长沙410083;中南大学粉末冶金国家重点实验室,长沙410083;宝山钢铁股份有限公司,上海201900;Warwick Manufacturing Group,The University of Warwick,Coventry,CV47AL,UK;广东伟业铝厂集团有限公司,佛山528000)

机构地区：[1]School of Materials Science and Engineering,Central South University,Changsha 410083,China [2]State Key Laboratory of Power Metallurgy,Central South University,Changsha 410083,China [3]Baoshan Iron&Steel Co.,Ltd.,Shanghai 201900,China [4]Warwick Manufacturing Group,The University of Warwick,Coventry,CV47AL,UK [5]Guangdong Weiye Aluminum Factory Group Co.,Ltd.,Foshan 528000,China

出　　处：《Transactions of Nonferrous Metals Society of China》2025年第1期60-76,共17页中国有色金属学报(英文版)

基　　金：financially supported by the Science and Technology Innovation Program of Hunan Province,China(No.2023RC3055);the Natural Science Foundation of Hunan Province,China(Nos.2023JJ30671,2020JJ4114);the Natural Science Foundation of Changsha City,China(No.Kq2208264);National Key Project of Research and Development Plan of China(Nos.2021YFC1910505,2021YFC1910504);the Young Core Teacher Foundation of Hunan Province,China(No.150220001);Key Research and Development Program of Guangdong Province,China(No.2020B010186002);the National Natural Science Foundation of China(No.51601229);the Key-Area Research and Development Program of Foshan City,China(No.2230032004640).

摘　　要：The corrosion behavior and microstructure characteristics of metal inert gas(MIG)welded dissimilar joints of the 6005A alloy modified with Sc(designated as 6005A+Sc)and the 5083 alloy were investigated using corrosion tests and microscopy techniques.Results show that the dissimilar joints exhibit strong stress corrosion cracking(SCC)resistance,maintaining substantial strength during slow strain rate tensile tests.Notably,the heat-affected zone(HAZ)and base metal(BM)on the 6005A+Sc side show superior performance in terms of inter-granular corrosion(IGC)and exfoliation corrosion(EXCO)compared to the corresponding zones on the 5083 side.The lower corrosion resistance of the 5083-BM and the 5083-HAZ can be attributed to the presence of numerous Al_(2)Mg_(3)phases and micro-scaled Al_(6)(Mn,Fe)intermetallics,mainly distributed along the rolling direction.Conversely,the enhanced corrosion resistance of the 6005A+Sc-BM and the 6005A+Sc-HAZ can be attributed to the discontinuously distributed grain boundary precipitates(β-Mg_(2)Si),the smaller grain size,and the reduced corrosive current density.采用腐蚀测试和电子显微组织表征方法,研究了Sc改性的6005A(6005A+Sc)和5083铝合金惰性气体保护焊异种接头的显微组织特征和腐蚀行为。结果表明:异种接头具有高应力腐蚀抗力,经慢应变速率拉伸测试后仍保留高强度。6005A+Sc侧热影响区和基材区的抗晶间腐蚀和剥落腐蚀性能均高于5083侧相应区,这主要是因为5083侧的基材区和热影响区沿轧制方向存在大量的Al_(2)Mg_(3)相和微米级别的Al_(6)(Mn,Fe)晶间相;而6005A+Sc侧基材区和热影响区β-Mg_(2)Si相非连续分布在晶界,且具有较小晶粒尺寸和低的腐蚀电流密度。

关 键 词：metal inert gas welding dissimilar joint aluminum alloy corrosion microstructure 

分 类 号：TG407[金属学及工艺—焊接] TG172