TITLE:
The Influence of Microscopic Fungi on Chromated Galvanized Zinc Coatings
AUTHORS:
Albinas Lugauskas, Igoris Prosyčevas, Aušra Selskienė, Irina Demčenko, Algirdas Narkevičius, Dalia Bučinskienė, Elena Binkauskienė
KEYWORDS:
Steel, Zinc Coating, Chromatic Solution, Microscopic Fungi, Influence
JOURNAL NAME:
Engineering,
Vol.2 No.12,
January
10,
2011
ABSTRACT: A solution containing Cr(VI), Cr(NO3)3 and its complex with an organic acid as well as several commercial solutions containing Cr(III) complexes with an organic acid and additionally CO2+, F-, SO42- ions were used for the studies. Results of the studies obtained in the following commercial solutions: Likonda 2AT, Cr(NO3)3 + malonic acid; Likonda 3Cr5 and Likonda 3CrMC are discussed. Steel coated with chromated Zn coatings was contaminated by some microscopic fungi. The variety of fungi on chromated plates diminished, however the propagules of fungi did not disappear completely. The Likonda 3Cr5 solution diminishes fungi contamination on chromated steel most effectively. In water used to rinse the surface of chromated plates the number of fungi propagules was detected to be higher as compared to that on the plate surface. The least quantity of fungi propagules was detected in water used to rinse plates coated in the Likonda 3Cr5 solution. The main part of fungi detected on chromated plates treated in the Likonda 3Cr5 solution were the fungi of Cladosporium species (C.herbarum, C.cladosporioides). The latter species also dominated on chromated plates coated with zinc and treated with the other solution. It should be mentioned, that on these plates chromated in this solution, Actinomycetes of the Streptomyces group were abundant. After comparison of surfaces of the plates treated in four solutions it has been determined that the surface of the plates treated in the Likonda 3Cr5 passivation solution and exposed to modelling conditions changed least of all. It has been noticed that on the subject studied white porous rust accumulates, the intensity of this process on the surface studied determines both the probability of corrosion and the resistance of the used safety means to the external factors.