Mg和Ti对A7N01铝合金腐蚀行为的影响  

Influence of Mg and Ti on Corrosion Behavior of A7N01 Al-alloy

作　　者：黄翠[1] 章淑芳[2] 胡洁[2] 王新 王晓敏[1] 

机构地区：[1]西南交通大学生命科学与工程学院,成都610031 [2]西南交通大学材料科学与工程学院,成都610031 [3]中车青岛四方机车车辆股份有限公司,青岛266111

出　　处：《腐蚀科学与防护技术》2018年第1期8-14,共7页Corrosion Science and Protection Technology

基　　金：国家重点研发计划(2016YFB0700505);四川省科技支撑计划(2016GZ0239)~~

摘　　要：针对Mg含量高Ti含量低的1#和Mg含量低Ti含量高的2#两种A7N01板材,通过应力腐蚀和电化学腐蚀测试,以及晶粒和第二相观察,考察Mg和Ti对A7N01铝合金腐蚀性能的影响。结果表明,Mg含量低Ti含量高的2#板材耐腐蚀性较差,表面由点蚀坑扩展并相互连接,断口应力腐蚀裂纹长度远大于Mg含量高Ti含量低的1#板材。2#板材的自腐蚀电位低,腐蚀电流密度大,腐蚀速率较高。两种板材的组织均呈纤维状变形晶粒,在基体上分布有η(Mg Zn2)相、Τ(Al2Mg3Zn3)相等强化相,以及含Fe、Mn、Si的杂质相。Ti含量的提高使2#板材的晶粒较小,细小的晶粒降低了材料的抗腐蚀性能。1#板材中Mg含量的增加,减少了第二相的数量,从而提高了材料的抗腐蚀性能。2#板材中杂质相分布相对集中,与基体的电位差导致2#板材的耐腐蚀性能降低。The influence of addition of Mg and Ti on the corrosion behavior of Al-alloy A7 N01 was studied by means of electrochemical corrosion test and stress corrosion cracking test, as well as observation of microstructure of the two plates of the A7 N01 with different Mg and Ti content. The results showed that the corrosion resistance of the plate 2# with low Mg content and high Ti content was worse in comparison with the plate 1# with high Mg content and low Ti content. The pits on surface of the plate 2# constantly grown and connected with each other, and the length of stress corrosion cracks of the plate 2#was longer than that of the plate 1#. While the corrosion potential was lower, and the corrosion current was higher for the plate 2#. The tow plates all showed fiber-like microstructure composed of η phase（Mg Zn2）, Τ phase（Al2 Mg3 Zn3） and a phase containing Fe, Mn and Si. The plate 2# with high Ti content possessed refined grains which led to the decreasing of corrosion resistance. However, the plate 1# with high Mg content possessed lower amount second phase, thus exhibited higher corrosion resistance. Furthermore, the relatively higher amount of the phase containing Fe, Mn and Si in the plate 2# could deteriorate its anti-corrosion property due to the galvanic corrosion between that phase and the matrix.

关 键 词：A7N01铝合金 晶粒 应力腐蚀 电化学腐蚀 

分 类 号：TG172[金属学及工艺—金属表面处理]