FIELD: chemistry.
SUBSTANCE: invention relates to use of an alkaline aqueous coating composition for applying a coating on zinc or zinc coated steel substrates, containing one or more alkali metal sulphates and / or ammonium sulphate and one or more alkali metal carbonates and / or ammonium carbonate and having pH from 9 to 12. Invention also relates to a method of applying non-reactive coating on zinc-coated or zinc alloy steel substrates using said compositions, which can be carried out before phosphatising of zinc-coated or zinc-alloyed steel substrates. Invention enables to obtain on zinc coating, providing excellent temporary corrosion protection, as well as significant lubricating properties, at the same time without negative effect on the next phosphating step, wherein coating is obtained with a small number of process steps without intermediate washing steps and is successfully used for zinc or zinc coated steel sheets of all types, including zinc-plated hot dip of steel.
EFFECT: disclosed is a solid lubricant for galvanized steel.
15 cl, 7 tbl
Authors
Dates
2019-06-24—Published
2015-06-16—Filed