敏化处理对AA5083铝合金的腐蚀和应力腐蚀开裂行为的影响  

Effects of Sensitization on Intergranular Corrosion and Stress Corrosion Cracking of AA5083 Al Alloy

作　　者：刘世凡 高文斌 顾小燕[1] 黎文航[1] 罗翊宸 LIU Shifan;GAO Wenbin;GU Xiaoyan;LI Wenhang;LUO Yichen(School of Materials Science and Engineering,Jiangsu University of Science and Technology,Zhenjiang 212003,China)

机构地区：[1]江苏科技大学材料科学与工程学院,江苏镇江212003

出　　处：《热加工工艺》2024年第12期93-99,共7页Hot Working Technology

基　　金：江苏省自然科学基金青年基金项目(BK20201000)。

摘　　要：铝镁系合金被广泛用于船舶建造和海洋结构,但是在服役过程中会在晶界析出低腐蚀电位的富镁相,引起环境断裂问题。研究了175℃/100 h敏化处理对铝合金AA5083的Al-Mg相析出行为、晶间腐蚀、电化学行为和应力腐蚀开裂性能的影响,并采用慢应变速率拉伸试验研究敏化前后的应力腐蚀开裂敏感性。结果表明,原始态材料不发生晶间腐蚀和应力腐蚀开裂,而经过敏化处理后,100 nm厚的β'-Al_(3)Mg_(2)或β-Al_(3)Mg_(2)相在晶界析出,导致材料发生严重的晶间腐蚀、电化学腐蚀以及应力腐蚀开裂。铝合金的应力腐蚀开裂行为是在裂纹尖端析出相的阳极溶解以及溶液酸化引发氢脆的协同作用下发生的。Al-Mg series alloys are widely used in ship building and marine structures.However,Mg-rich phases with low corrosion potential can precipitate along the grain boundaries after in service,inducing stress corrosion cracking.The effects of 175℃/100 h sensitization on the Al-Mg phase precipitation behavior,intercrystalline corrosion,electrochemical behavior and stress corrosion cracking properties of AA5083 were studied,and the slow strain rate tensile test was used to study the sensitivity of stress corrosion cracking before and after sensitization.The results show that no intercrystalline corrosion and stress corrosion cracking occur in raw materials.After sensitization treatment,the 100 nm thickβ'-Al_(3)Mg_(2)orβ-Al_(3)Mg_(2)phase is precipitated at the grain boundary,resulting in serious intercrystalline corrosion,electrochemical corrosion and stress corrosion cracking of the material.The stress-corrosion cracking behavior of aluminum magnesium series alloy occurs under the synergistic action of the anode dissolution of the crack tip precipitate phase and the hydrogen embrittlement caused by the solution acidification.

关 键 词：铝镁系合金 富镁相 晶间腐蚀 电化学行为 应力腐蚀开裂 

分 类 号：TG178[金属学及工艺—金属表面处理]