Selection and evaluation of single-layer coating compositions in corrosive environments

The objective of the work was to select a suitable methodology for accelerated corrosion tests of single-layer coating compositions (hereinafter referred to as CC), to assess the condition of coatings during corrosion tests and to evaluate the resistance of the monitored single-layer CCs after the completion of the tests in selected corrosive environments. The results were used for the determination of the potential use of the selected single-layer coating compositions in agricultural environments. The following single-layer, water-based CCs were applied to sheet steel samples: V 2026, Aquapol_J and Denapox EZ. The following synthetic CCs were selected: AR 40-00, Krahokryl_J and ACS 20-ST. The resistance of these coatings was tested in 5 corrosive environments: in NaCl environment according to CSN EN ISO 7253, in SO2 environment according to CSN EN ISO 3231 and in the environment of a condensation chamber with de-ionized water according to CSN 03 8131. To simulate agricultural environments, solutions of the Cererit fertilizer and pig semi-liquid manure were selected. The samples were left in the condensation chamber in aqueous environment according to CSN 03 8131 for 8 hours and then soaked in Cererit or semi-liquid manure and left in the laboratory environment for 16 hours. Samples were evaluated according to CSN EN ISO 4628-1, 2, 3. The water-based CC Denapox EZ and the synthetic CC AR 40-00 reached the best results.