Characteristics of Rich Phytic Passivator without Cr for Brass Strip

Abstract:

The surface of brass strip is easily oxidized to cause discoloration when exposed in the air. If it contacts with the electrolyte, there will be an electrochemical reaction in the surface that lead to increasing dezincification corrosion. To improve the anti-tarnish ability, the best method is to form a protective membrane in the strip surface. Phytic acid is easily formed a stable chelate complex compound with metal ions, so that forming a dense layer to protect brass strip. It is necessary to develop a new type surface passivator which rich in phytic acid and aquae hydrogenii dioxide but without Cr which pollutes the environment. The study results show that: This passivator enable the anti-tarnish capacity significantly, and do much better results and without so much pollution than now often used dichromate passivator. The passivator solution is stable and can use longer.

• Periodical: Advanced Materials Research (Volumes 239-242)
• Pages: 2257-2260
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.239-242.2257
• Online since: May 2011
• Authors: Wei Cai, Ren Hui Liu, Hong Yang, Xiang Peng Xiao
• Keywords: Anti-Tarnish, Brass Strip, Hydrogen Peroxide, Phytic Acid, Sodium Silicate, Surface Passivator

References

[1] Liu Yu-bo. Surface treatment Daquan [M].Beijing: Chinese measurement Press,1996.

[2] Lin L F, Polan. Anti-tarnish treatment of metal foil [P].US Pat: 5057193, 1991- 10-15.

[3] Lin W, Yin J G,Otieno Alego V, etal. The inhibitive effects of phytic acid and Ca, Mg and Na-salts of phytic acid on copper corrosion in domestic water [J]. Journal of Yunnan University,1999,21 (4) :275-278.

DOI: 10.1016/0010-938x(94)00105-f

[4] NOTOYA T, OTIENO-ALEGO V, SCHWEINSBERG D. The corrosion and polarization behaviour of copper in domestic water in the presence of Ca, Mg and Na-Salts of phytic acid[J]. Corrosion Science, 1995, 37 (1) :55-65.

DOI: 10.1016/0010-938x(94)00105-f

[5] LIU J R , GUO Y N , HUANG W D. Study on the corrosion resistance of phytic acid conversion coating for magnesium alloys[J] . Surface and Coatings Technology,2006,201: 1536 -1541.

DOI: 10.1016/j.surfcoat.2006.02.020

[6] YIN Ren-he,WAN Zong-yue,XU Qun-jie etal.Study of self-assembled monolayer of plant acid for B30 corrosion and its inhibiting mechanism [J]. Function Materials,2007,38(4):562-565.

[7] GU Wei-jing,WANG Li-yan,WANG Xi-di,FAN et al. The corrosion inhibition study of phytic acid on different copper surface by electrochemistry [J]. Journal of Shanghai Normal University,2009,38(5):501-505.

[8] Graf E.Applications of Phytic Acid [J]. Journal of the American Oil Chemists' Society, 1983,60(11): 1861-1867.

DOI: 10.1007/bf02901539

[9] BI Yan-lan,XU Xue-bing,ZHANG Gen-wang. Extraction of phytic acid and Review of Progress in Applied [J]. Grain and fat,1995,(2) :38-43.

[10] Bishep C V, Foley T J, Frank J M. Coating solutions of trivalent chromium for coating zinc surfaces [P]. US Pat: 4171231, 1979-10-16.