Electrochemical mechanism of metall corrosion

Issue 26(1) 2021
Pages 41-47

A.N. Podobayev, Moscow Polytechnic University, Moscow, Russian Federation
I.I. Reformatskaya, Academy of the State Fire Service Emercom of Russia, Moscow, Russian Federation


Keywords: corrosion, electrochemistry, mechanism, metal, dissolution, polarization diagram

doi: 10.31615/j.corros.prot.2021.99.1-4

 

Corrosion that occurs by an electrochemical mechanism is a combination of cathodic and anodic reactions that occur independently of each other. At that, the metal surface is considered to be equipotential one, i.e. the presence of short-circuited microgalvanic pairs on the surface is not a necessary condition for electrochemical corrosion. The anode and cathode processes are spatially separated. This is provided by the presence of conduction electrons in the interstitial spaces of the metal lattice. The present model of electrochemical corrosion justifies the use of polarization diagrams for the analysis of corrosion processes. The previously proposed model, based on the idea that a necessary condition for electrochemical corrosion is the presence of short-circuited microgalvanic elements on the metal surface, is erroneous. When considering electrochemical corrosion from the positions of this model, the use of polarization diagrams to study corrosion processes is not legitimate.