新型Al-Mg合金的耐腐蚀性能

发布时间：2018-05-28 09:46

本文选题：金属材料 + Al-Mg合金　；参考：《材料研究学报》2015年08期

【摘要】：采用晶间腐蚀、剥落腐蚀实验结合扫描、透射电镜等手段观察分析腐蚀后合金的微观形貌和相结构,研究了合金元素和热变形工艺对新型Al-Mg合金的抗晶间腐蚀和剥落腐蚀性能的影响。结果表明:随着Mg含量的增加合金在浓硝酸溶液中的腐蚀失重量增大,抗晶间腐蚀性能降低;合金中Zn含量的的提高导致在晶界上形成了不连续析出的Mg32(Al,Zn)49相,降低了合金的腐蚀失重量,提高了Al-Mg合金的抗晶间腐蚀性能。合金的抗腐蚀性能也受形变热处理工艺的影响,对冷变形后的合金进行适当的稳定化处理,相比单纯的冷变形可同时提高合金的抗晶间腐蚀性能与剥落腐蚀性能。冷变形后的残余应力、高位错密度以及拉长晶粒形貌都导致更多的析出相在晶界连续析出,形成网状膜,使合金的抗腐蚀性能降低。
[Abstract]:The microstructure and phase structure of the corroded alloy were observed by means of intergranular corrosion, exfoliation corrosion test, scanning electron microscope and transmission electron microscope. The effects of alloying elements and hot deformation process on intergranular corrosion and exfoliation corrosion of new Al-Mg alloy were studied. The results show that with the increase of mg content, the corrosion loss of the alloy in concentrated nitric acid solution increases, and the intergranular corrosion resistance decreases, and the increase of Zn content in the alloy results in the formation of discontinuous precipitated Mg32 / AlZnZN _ (49) phase at grain boundaries. The corrosion loss weight of Al-Mg alloy was reduced, and the intergranular corrosion resistance of Al-Mg alloy was improved. The corrosion resistance of the alloy is also affected by the thermomechanical treatment. The proper stabilization treatment of the alloy after cold deformation can improve the intergranular corrosion resistance and the exfoliation corrosion resistance of the alloy compared with the cold deformation alone. The residual stress, high dislocation density and elongated grain morphology after cold deformation all result in the continuous precipitation of more precipitated phases at grain boundaries, resulting in the formation of a network film, which reduces the corrosion resistance of the alloy.
【作者单位】：北京科技大学新金属材料国家重点实验室;
【基金】：国家自然科学基金51301017 现代交通金属材料与加工技术北京实验室课题和新金属材料国家重点实验室自主课题2014Z-09资助项目~~
【分类号】：TG146.21

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