بررسي مكانيسم هاي خوردگي پوششهاي شيشه اي بر روي فولاد

Evaluation of corrosion mechanisms in glass coatings on the steel

The aim of this research was evaluation of corrosion mechanisms in vitreous coatings on steel. In general, glasses are among of the most durable materials against chemical agents, water and acids. Glass and glass coatings have found extensive applications in chemical industries, mostly as containers for corrosive fluids, liner for chemical reactors as well as electrical insulators and stabilizing of radioactive waste disposals. For better understanding of corrosion mechanisms of glass coating, two enamels, CE (Cobalt Enamel) and FCE (Free Cobalt Enamel) were examined. Chemical durability and corrosion mechanisms of the samples were investigated using weight loss technique and Fourier Transform Infrared Reflectance (FTIR). Microstructure of the bubbles and their influence on the corrosion resistance of the coatings were studied using optical microscopy and scanning electron microscopy (SEM). The results showed that chemical resistance of FCE was higher than CE. The corrosion mechanism of CE was mainly based on glass network dissolution in acid while in FCE, ion exchanging between the alkaline ions from glass and hydronium ions was responsible for the corrosion.