Yellow chromate coating provides better adhesion of the paint to the surface and high corrosion resistance for the parts to be painted on aluminum surfaces. High corrosion resistance is also available for unpainted parts. It is a type of coating that meets the standards especially in the defense industry and its use is widespread. For yellow chromate coating, the surface must be cleaned from oil and oxide layers. Since the coating takes place in acidic solution, the boilers must be made of stainless or polypropylene material. As a result of the sequential processes applied in chromate coating lines, a light yellow to dark brown coating is formed on aluminum. As the color darkens, the coating thickness increases. The chromate bath solution and the coating itself contain +6 valent chromium (Cr+6). Before discharging the baths, it is required to convert the chromium to +3 chromium.
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