If I understand your question, the corrosion rate corresponds to an anodic process. If the corresponding cathodic process is only hydrogen evolution, then the current consumed in the hydrogen evolution is the same as that produced in the oxidation (corrosion) process. Thus, knowing the corrosion rate you may calculate the anodic current, equal to the cathodic current, and the, by using the Faraday equation, you may calculate the hydrogen production.

Thanks for your answer.

Faraday's law of electrolysis can be used to estimate the amount of hydrogen gas produced during corrosion. The law relates the amount of a substance produced or consumed during an electrochemical reaction to the amount of charge passed through the system. The equation can be expressed as follows:

M = Q/(nF)

where M is the amount of substance produced (in grams), Q is the amount of charge passed (in Coulombs), n is the number of electrons involved in the reaction, and F is the Faraday constant (96,485 Coulombs per mole of electrons).

In the case of hydrogen gas production during corrosion, the reaction can be represented as follows:

Fe + 2H2O → Fe(OH)2 + H2

This reaction involves the transfer of two electrons and the production of one mole of hydrogen gas for every mole of iron corroded.

Assuming that the reaction proceeds with 100% efficiency, the amount of hydrogen gas produced can be calculated using the Faraday equation as follows:

M(H2) = Q/(2F)

where M(H2) is the amount of hydrogen gas produced (in grams), Q is the amount of charge passed (in Coulombs), and F is the Faraday constant.

Note that in practice, the efficiency of the reaction may be less than 100%, and there may be other factors that affect the amount of hydrogen gas produced. Therefore, the estimated amount of hydrogen gas production should be considered as an approximation, and should be validated with experimental measurements if possible.

Here are some references that may be useful for further information on measuring hydrogen gas production during corrosion: