Phosphatizing of Metals With Easily Detachable Polymer Coatings

Abstract

The phosphate treatment of ferrous metals with easily peeled off polyamide (PFE2/10) coatings was investigated. The coatings contain various phosphatizing agents including ammonium dihydrophosphate, ammonium molybdate, sodium hexamethaphosphate, and anti-adhesives (oleic acid, N-cethylpyridinchloride) as well as such corrosion inhibitors as sodium nitrites and hydroxylamine. The film adhesive strength as a function of concentration, its nature and drying duration was established. The efficiency of phosphatizing agents was assessed using electrochemical and X-ray structural investigation methods and optical surface analysis. The protective features of the phosphate films received their theoretical foundation, which was confirmed by the experiments. Peeling force of the polymer film was determined and the optimal phosphatization composition was proposed.