Datsko B. Evaluating the effectiveness of metal and paintwork coatings for corrosion protection of steel in the hydrogen sulfide of environments

The dissertation is devoted to the determination of anticorrosion properties of zinc, aluminum and paint coatings on steel in hydrogen sulfide of the environments, including in the presence of mechanical stresses and the development of practical recommendations for their used. It has been shown for the first time that insoluble corrosion products due to insufficient adhesion to the surface do not contribute to the long-term passivation of arc spray metalizing and hot-dip of zinc coatings in model seawater with hydrogen sulfide. On the basis of the developed and scientifically based electrochemical graphical-analytical method it has been established that the critical interrelations the of area steel to the damaged aluminum coating for which its tread protection still the act, is more than an order higher than zinc in the hydrogen sulfide environments. It has been determined the destruction stresses of arc spray metalizing aluminum, hot-dip zinc and epoxy coatings on steel 20, which are 0,7... 0,8 σ0.2, 0.9 ... 1,1 σ0.2 and ~1,2 σ0.2. It has been shown that in seawater saturated with hydrogen sulfide they increase the threshold stresses to the level σth/σ0.2= 0,8 and in the solution NACE to - σth/σ0.2= 0,7 ... 0,8. The use of combined coatings of the arc spray metalizing aluminum with epoxy Jotamastic 87GF (δ ≈ 100 μm) or Vimpel® epoxy SF mastic (δ ≈ 100 μm) increases the threshold stresses to σth/σ0.2= 0,9. Recommendations and technological regulation on the application of combined coatings for corrosion protection of steel structures in the hydrogen sulfide environments for the state enterprise "Lvivanticor" and LLC "Yotungard Ukraine" has been developed. Keywords: steel, zinc, aluminum, paint and varnish coatings, tension, adhesion, hydrogen sulfide, corrosion, corrosion cracking.