A6061-T6铝合金焊接接头腐蚀行为
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摘要
A6061-T6铝合金材料是轨道车辆制造的主要结构材料。轨道车辆在线路运行时受运行环境的影响,尤其是沿海、地下潮湿环境对车辆结构容易造成较为严重的腐蚀损伤,进而影响到车辆的安全可靠性。以轨道车辆常用的A6061-T6铝合金焊接接头为研究对象,对焊接接头的腐蚀失重、电化学腐蚀性能进行系统性研究。结果表明:腐蚀失重速率先快速增长,在14 d时达到最大,然后随着腐蚀时间的进一步延长,失重逐渐减小,呈现平稳下降趋势。母材和焊缝在质量分数为5%的不同腐蚀溶液中的自腐蚀电位随Cl~-、SO_4~(2-)、NO_3~-顺序依次变正,而自腐蚀电流随Cl~-、SO_4~(2-)、NO_3~-顺序依次变小。SO_4~(2-)对铝合金的腐蚀加速作用弱于Cl~-而强于NO_3~-。
A6061-T6 aluminum alloys is the main structure materials for vehicle manufacture. The train body had suffered severe corrosion damage under the effect of coastal,underground humidity and would affect the reliability of structures. This paper focused on the A6061-T6 aluminum alloy welded joints and study the weight loss,electric chemistry corrosion properties. The results showed that the rate of corrosion weight loss first showed a rapid increase,reaching a maximum at 14 th day,and then with the further extension of the corrosion time,the weight loss gradually decreased,showing a steady decline. The self corrosion potential had become positive with the order of Cl~-、SO_4~(2-)、NO_3~-of base metals and weld but the self corrosion current had become small at the 5% mass fraction of different corrosion solution. The corrosion acceleration effect of SO_4~(2-)was weaker than Cl-but higher than NO_3~-.
A6061-T6 aluminum alloys is the main structure materials for vehicle manufacture. The train body had suffered severe corrosion damage under the effect of coastal,underground humidity and would affect the reliability of structures. This paper focused on the A6061-T6 aluminum alloy welded joints and study the weight loss,electric chemistry corrosion properties. The results showed that the rate of corrosion weight loss first showed a rapid increase,reaching a maximum at 14 th day,and then with the further extension of the corrosion time,the weight loss gradually decreased,showing a steady decline. The self corrosion potential had become positive with the order of Cl~-、SO_4~(2-)、NO_3~-of base metals and weld but the self corrosion current had become small at the 5% mass fraction of different corrosion solution. The corrosion acceleration effect of SO_4~(2-)was weaker than Cl-but higher than NO_3~-.
引文
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[4]Guoqing Gou,Jia Chen,Zhirui Wang,et al.Stress Corrosion Cracking Behavior of 4.19%Zn-1.34%Mg(A7N01S-T5)Aluminum Alloy Welded Joints[J].Corrosion,2016,72(9):1133-1145.
[2]Asaro R J,Tiller W A.Interface Morphology Development during Stress Corrosion Cracking:Part I.Via Surface Diffusion[J].Metallurgical Transactions,1972,3(7):1789-1796.
[3]JoséR Galvele.A Stress Corrosion Cracking Mechani sm Based on Surface Mobility[J].Corrosion Science,1987,27(1):1-33.
[4]Guoqing Gou,Jia Chen,Zhirui Wang,et al.Stress Corrosion Cracking Behavior of 4.19%Zn-1.34%Mg(A7N01S-T5)Aluminum Alloy Welded Joints[J].Corrosion,2016,72(9):1133-1145.