通过缝隙腐蚀浸泡实验考察了钼酸铵((NH_4)_6Mo_7O_24)和氯化铈(CeCl_3)对2024铝合金在海水中缝隙腐蚀行为的影响,采用扫描电子显微镜(SEM)及能谱EDAX对腐蚀试样表面形貌进行了观察,并分析了试样表面膜成分;结合动电位极化和交流阻抗对其抗缝隙腐蚀机理进行了讨论.结果表明:钼酸铵不能有效地抑制2024铝合金在海水中的缝隙腐蚀,虽然钼酸铵可以在缝隙外表面形成保护膜,但缝隙内的腐蚀却更为严重;而在含氯化铈的海水中,由于Ce~(3+)的还原性降低了缝隙内外氧的浓度差,有效抑制了缝隙腐蚀的发生.
The influence of addition of(NH_4)_6Mo_7O_24 and CeCl_3 on crevice corrosion behavior of 2024 a-luminum alloy was investigated in this paper. The surface morphology of the alloy after immersion was ob-served by scanning electron microscopy (SEM), and the corrosion product was analysed by EDAX. The corrosion mechanism was discussed in terms of the measurement results of potentiodynamic polarization and electrochemical impedance spectroscopy(EIS). The results revealed that(NH_4)_6Mo_7 O_24 could not in-hibit the crevice corrosion of 2024 aluminum alloy in seawater. A protective film was formed outside the crevice in the presence of(NH_4)_6Mo_7O_24, but the corrosion rate of inside the crevice was accelerated. However, Ce~(3+) improved the crevice corrosion resistance, due to the effect of reduction characteristic of Ce~(3+) the concentration difference of oxygen inside and outside the crevice wao reduced.
参考文献
| [1] | 卞贵学,陈跃良,郁大照.LY12铝合金初始不连续状态研究[J].强度与环境,2007,34(5):58. |
| [2] | 张有宏,吕国志,陈跃良.LY122CZ铝合金预腐蚀及疲劳损伤研究[J].航空学报,2005,26(6):579. |
| [3] | 王成,江峰,林海潮.钼酸铵对LYl2铝合金的缓蚀作用[J].腐蚀与防护.2001,22(3):115. |
| [4] | Palavnivel V,Huang Y,Van Ooij W J.Effects of addition of corrosion inhibitors to silane films on the performance of AA2024-T3 in a 0.5 M NaCl solution[J].Progress in Organic Coatings,2005,53(2):153. |
| [5] | ASTM G78-01,Crevice Corrosion Testing of Iron-Base and Nickel-Base Stainless Alloys in Seawater and Other Chloride-Containing Aqueous Environments[S].2001. |
| [6] | GB 13670-92,不锈钢缝隙腐蚀电化学试验方法[S].1992. |
| [7] | Mishra A K,Balasubramaniam R.Corrosion inhibition of aluminium by rare earth chlorides[J].Materials Chemistry and Physics,2007,103 (2,3):385. |
| [8] | Moutarlier V,Gigandet M P.Molybdatelsulfuric acid anodising of 2024-aluminium alloy:influence of inhibitor concentration on film growth and on corrosion resistance[J].Surface and Coatings Technology,2003,173(1):87. |
| [9] | 黄燕.稀土在含Cl~-介质中对铝合金孔蚀的缓蚀规律及机理研究[J].湖南理工学院学报(自然科学版),2004,17(4):59. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%