Effect of Hydrogenation on Hardness of Metallic Materials Used in Oil and Gas Industry

When transporting and storing hydrocarbons, one of the main operational problems is the external and internal corrosive wear of the metal. A frequent cause of accidents in main and technological gas pipelines due to their stress corrosion cracking is the enrichment of the pipe body with hydrogen. Literature experimental data on the effect of hydrogen on the hardness of iron and low-carbon steels during their electrolytic saturation with hydrogen are analyzed. It is noted that the curves of changes in hardness in all the analyzed sources for all these materials have a similar form: at the initial stage of hydrogenation, the hardness increases, reaching its maximum, and then it declines to values close to the initial level follows. At the same time, the time to reach the maximum hardness decreases with the introduction of promoters into the electrolyte solution, which can be Na2S, As. Increasing the current density during electrolysis increases the value of the maximum hardness. The time to reduce the hardness to the initial level is approximately the same as the hydrogenation time required to achieve maximum hardness. Possible explanations of the regularities obtained by the authors are given.