Protective Composite Fluoropolymer-Containing Coatings on St3 Steel Formed Using Cold Gas-Dynamic Spraying Technology

The article presents the results of studying the coatings formed using different methods by means of cold gas-dynamic spraying (CS) on the surface of structural steel St3. Various methods for forming protective polymer-containing coatings are proposed. The composition and morphology of the protective layers are studied using the SEM–EDS analysis method. The anticorrosive properties of the coated samples were studied using the electro-chemical impedance spectroscopy and potentiodynamic polarization method during exposure to 3.5 wt.% NaCl solution. It is shown that the inclusion of superdispersed polytetrafluoroethylene (SPTFE) in the coating increases the corrosion resistance of the base copper-zinc layer. The best anticorrosive properties were established for a sample with a basic Cu-Zn CS layer annealed at 500 °C for 1 h, followed by SPTFE treatment and repeated annealing at 350 °C for 1 h. The obtained results indicate that polymer-containing coatings formed by the CS method effectively increase the protective properties of the treated material.