Effect of Plastic Deformation on Hydrogen Diffusion Behavior of Martensitic Steel in Hydrogen Absorption Environment

Abstract

This study investigates the effect of plastic deformation on hydrogen permeation behavior of martensitic steel using electrochemical hydrogen permeation methods. The values of hydrogen diffusivity in plastically deformed martensitic steel were investigated from a microstructural aspect. Additionally, thermal desorption spectroscopy was performed to verify the tendency of plastic deformation due to hydrogen trapping. It was observed that as the plastic strain applied on the martensitic steel increased, value of hydrogen diffusion coefficient decreased and hydrogen concentration increased. The decrease in hydrogen diffusion coefficient and an increase in hydrogen trapping in the plastically deformed martensitic steel were attributed to an increase in reversible trapping sites caused by strain-induced dislocations.

Fig. 6 Results of hydrogen permeation test on the martensitic steels with various pre-strain values in the 0.5 M H₂SO₄ + 0.25 g/L NH₄CSN solution at room temperature: (a) hydrogen permeation current density and (b) normalized flux.