热镀锌件铬酸盐转化膜耐蚀性优良,但环境污染严重;铈盐转化膜效果差,复合铈盐转化膜耐蚀好,成本高;镧盐转化膜无毒,耐蚀效果比铈盐好.采用以La(NO3)3为主盐的成膜溶液浸泡热镀锌层,获得了La盐转化膜.通过SEM,EDS和电化学测试方法对La盐转化膜层的结构和耐蚀性能进行了研究.结果表明:转化膜随浸泡时间增加而增厚,膜的极化电阻和电化学阻抗也随之增大;膜层中存在均匀分布的微裂纹,且随膜增厚而扩宽;处理时间过长,膜的表层开裂脱落,极化电阻和电化学阻抗下降.浸泡30 min所获La盐转化膜,极化电阻和EIS低频阻抗达20 kΩ·cm2以上,耐蚀性能远高于单一铈盐转化膜,极大地提高了热镀锌件的耐蚀性能.
参考文献
| [1] | 单凤君,刘常升,于晓中,王双红.镀锌钢板无铬钝化技术的研究进展[J].材料保护,2007(10):45-49. |
| [2] | 孔纲,林碧兰,刘军,卢锦堂.热镀锌层磷化膜硝酸铈封闭后处理的研究[J].材料保护,2008(02):8-10. |
| [3] | Montemor MF.;Simoes AM.;Ferreira MGS. .Composition and corrosion behaviour of galvanised steel treated with rare-earth salts: the effect of the cation [Review][J].Progress in Organic Coatings: An International Review Journal,2002(2):111-120. |
| [4] | Aramaki K .Treatment of zinc surface with cerium(Ⅲ) ni trate to prevent zinc corrosion in aerated 0.5 M NaCl[J].Corrosion Science,2001,43(11):2 201-2 215. |
| [5] | Arenas MA;de Damborenea JJ .Surface characterisation of cerium layers on galvanised steel[J].Surface & Coatings Technology,2004(2/3):320-325. |
| [6] | LU Jin-tang,WU Hai-jiang,KONG Gang,CHE Chun-shan,XU Qiao-yu.Growth and corrosion behavior of rare earth film on hot-dip galvanized steel[J].中国有色金属学会会刊（英文版）,2006(06):1397-1401. |
| [7] | 吴海江,卢锦堂,孔纲.热镀锌钢表面铈盐与硅烷处理后的耐蚀性能[J].腐蚀与防护,2007(07):353-356. |
| [8] | Ferreira M G S;Duarte R G;Montemor M F et al.Silanes and rare earth salts as chronmte replacers for pre-treatments on galvanised steel[J].Electrochimica Acta,2004,49(17-18):2 927-2 935. |
| [9] | M.F.Montemor;A.M.Simoes;M.G.S.Ferreira .Composition and behaviour of cerium films on galvanised steel[J].Progress in Organic Coatings: An International Review Journal,2001(4):274-281. |
| [10] | LU Jin-tang;KONG Gang;CHEN Jin-hong .Growth and corrosion behavior of molybdate passivation film on hot dip galvanized steel[J].Transactions of Nonferrous Metals Society of China,2003(1):145-148. |
| [11] | Cachet C;Ganne F;Joiret S et al.EIS investigation of zinc dissolution in aerated sulphate medium.Part Ⅱ:Zinc coatings[J].Electrochimica Acta,2002,47(21):3 409-3 422. |
上一张
下一张
上一张
下一张
计量
- 下载量()
- 访问量()
文章评分
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%