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。
The corrosion behavior of the newly developed AI-Mg alloys was investigated in terms of their alloying element and thermo-mechanical treatments by means of intergranular corrosion test, exfoliation corrosion test, scanning electron microscopy and transmission electron microscopy. The results show that, with the increase of Mg content the mass loss of the alloys in concentrated nitric acid increased, correspondingly their intergranular corrosion resistance decreases. Zn addition to the AI-Mg alloys led to the formation of Mg32（Al, Zn）49 phase at the grain boundary, which dramatically increased the intergranular corrosion resistance of the alloys. The corrosion resistance of the alloys was also modified by thermo-mechanical treatment. Both intergranular corrosion resistance and exfoliation corrosion resistance of the alloys were dramatically increased by a proper post stabilizing treatment after cold rolling reduction. The residual stress, higher dislocation density and morphology of elongated grains after cold rolling reduction can lead to more continuous precipitation at the grain boundary, thus decrease the corrosion resistance of the alloys.
出处
《材料研究学报》
EI
CAS
CSCD
北大核心
2015年第8期576-582,共7页
Chinese Journal of Materials Research
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~~
关键词
金属材料
AL-MG合金
晶间腐蚀
剥落腐蚀
稳定化处理
metallic materials, Al-Mg alloys, intergranular corrosion, exfoliation corrosion, stabilizing treatment
