Corrosive behavior of low-alloy structural steels

Structural mechanics

Increasing the corrosion resistance of low-alloy steels containing less than 2.5% of doping components (except carbon), which are actively used in the construction of various buildings and structures, is one of the priorities in the development of the modern construction industry. This problem becomes especially urgent during operation of stressed elements of various structures, which are used in the conditions of possible surface exposure to moisture. As part of the research, the results of which are presented in this article, we have examined the possible reduction in the rate of electrochemical corrosion of low-alloy steels in a natural corrosive environment. The purpose of the study was to establish the effect of the composition of steels on their corrosive properties. The main method chosen was a method of thermodynamic potentials, used in conjunction with model ideas about ideal gas and free energy of diffusion of liquid, solid and gaseous solutions. The present study analyzes the process of formation of ideal binary alloy, based on which the relationship between the thermodynamic characteristics of its original components and the corrosive behavior of the alloy was established. In order to verify the detected corrosion mechanism, the process of amalgam anode dissolution was considered, which fully confirmed the results obtained earlier.  Based on the analysis conducted, it can be concluded that the equilibrium potential of the ideal binary alloy in the electrolyte in no way depends on the process of its formation from the pure original components. It is determined solely by the ratio of energy characteristics of metal ions actually in the alloy, as well as the energy characteristics of the same ions in the solution of electrolyte, which comes into contact with the alloy.