摘要
用质量分数为3.5%的NaCl溶液70℃腐蚀5 mm厚6082-T6/6005A-T6异种铝合金铆接接头,研究其疲劳破坏行为。结果表明:空气中铆接接头疲劳极限为4.48 kN,失效位置为铆体帽沿根部;腐蚀介质中铆接接头疲劳极限为3.6 kN,腐蚀疲劳载荷大于4 kN时,失效位置与空气中一致,低于4 kN时疲劳裂纹始于6005A侧母材表面约500μm厚的粗晶层,且沿晶开裂。去除粗晶层制成的铆接接头腐蚀疲劳极限为3.97 kN,疲劳载荷低于4 kN时,裂纹始于表面细晶,并存在约50μm沿晶开裂。腐蚀环境改变了铆接接头疲劳失效模式,6005A铝合金与异种材质相比在腐蚀介质中腐蚀电位最低,表层晶粒尺寸和晶界析出相是影响铆接接头腐蚀疲劳性能的主要因素。
The effect of the corrosion condition of 3.5% NaCl solution at 70 ℃ on the fatigue failure behavior of 6082-T6/6005AT6 dissimilar aluminum alloy riveted joints was investigated. The results show that the fatigue limit of riveted joints is 4.48 kN in the air with failure at the root of rivet body brim,which is 3.6 kN in corrosive medium. In corrosive medium,when the max fatigue load is bigger than 4 kN,the joints fail at the same position as that in the air,while the max load reduces to 4 kN and below,the cracking along grain boundary originates from the coarse grain layer with a thickness of 500 μm on the surface of base metal on the side of 6005A aluminum alloy base metal of riveted joint. The corrosion fatigue limit of riveted joints made by removing coarse grain layer from thick plates in the same batch is 3.97 kN,and when the max load is lower than 4 kN,the cracking along grain boundary with a length of 50 μm originates from fine grain on the surface of riveted joint. Corrosion condition changes the fatigue failure mode of riveted joints. Compared with dissimilar materials,6005A aluminum alloy has the lowest corrosion potential in corrosive medium. The surface grain size and phases precipitated at grain boundary are the main factors affecting the corrosion fatigue strength of aluminum alloy riveted joints.
作者
武永寿
韩晓辉
徐智宝
李刚卿
谈雅群
梁景恒
郑自芹
WU Yongshou;HAN Xiaohui;XU Zhibao;LI Gangqing;TAN Yaqun;LIANG Jingheng;ZHENG Ziqin(CRRC Qingdao Sifang Co.Ltd.,Qingdao 266111,China;Ningbo Branch of Chinese Academy of Ordnance Science,Yantai 264003,China)
出处
《兵器材料科学与工程》
CAS
CSCD
北大核心
2022年第3期71-75,共5页
Ordnance Material Science and Engineering
基金
与企业合作横向课题。
