Influence of the Products of Electrochemical Destruction of Protective Coatings on the Properties of Pipe Steel in Low-Alkaline Media

We investigate the influence of the products of electrochemical destruction of polymeric tape protective coatings formed in low-alkaline media under the conditions of cathodic polarization at 1.5 V (s.c.e.) and without cathodic polarization for different times on the corrosion, electrochemical, and stress-corrosion properties of pipe steel. It is shown that, for 2.5 months, the pH value shifts toward the alkaline region and the electric conductivity of the medium increases. We reveal an increase in the corrosion rate of pipe steel and its susceptibility to stress-corrosion cracking in the medium of model soil electrolyte in which the destruction of the coating occurs for 2.5 months both under the conditions of cathodic polarization and without it. It is demonstrated that the chemical composition of the polymeric film remains almost constant in the process of destruction.