PSI - Issue 75

KADIRI Mounir et al. / Procedia Structural Integrity 75 (2025) 633–641 KADIRI Mounir/ Structural Integrity Procedia (2025)

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To limit hydrogen desorption after the cathodic treatment, a zinc coating was applied by electrodeposition at a controlled temperature of 40°C for 10 minutes under a fixed current density of -25mA/cm². The electrodeposition process forms a homogeneous zinc layer on the specimen surface, acting as a barrier against hydrogen diffusion to the exterior.

Figure 1 : hydrogen charging procedure for cathodic polarization

2.3. Tested configurations To highlight the effect of hydrogen on the self-heating curves, three configurations of specimen, whose geometry is shown in Figure 2, were tested: base material specimens’, hydrogen charged and coated specimens and coated but uncharged specimens. The coated uncharged configuration enabled assessment of the coating’s effect on energy dissipation during the self-heating test. Hydrogen charging was performed by cathodic polarization to introduce hydrogen into the base material. Additionally, the charged specimens were coated with a zinc layer, a material known to block hydrogen diffusion at the steel surface, thus minimizing hydrogen desorption during the self-heating tests.

Figure 2 : Geometry of sample

2.4. Procedure for the self-heating method The energy dissipated from the material under cyclic loading generates a thermal field whose intensity depends on several parameters, such as the volume and the sample geometry, the material thermal properties, the thermal boundary conditions and the intensity of the thermal source associated with irreversible mechanisms (Amini et al. 2020). The self-heating phenomenon arises from the energy dissipated from the material. The heat equation links what is