M.M. Llera, V. Arniella, G. Álvarez, F.J. Belzunce, C. Rodríguez
International Journal of Fatigue
https://doi.org/10.1016/j.tafmec.2026.105661
Resumen
HThe fatigue crack growth rate of a 42CrMo4 steel under electrochemical hydrogen charging was analysed. Different test variables were examined in order to correlate the performance of the steel under electrochemical charging and under hydrogen gas pressure. Two electrolytes were used (saline and an acid solution), and different cathodic current densities to compare the effect of the amount of hydrogen introduced into the steel microstructure. Fatigue test frequencies were also varied between 0.01 Hz and 1 Hz. Results indicate that test frequency is the most influential parameter in accelerating the fatigue crack growth rate under electrochemical hydrogen charging because the hydrogen absorption at the crack tip is quite slow. It was demonstrated that using an acid electrolyte at a current density of 0.5 mA/cm2 and a frequency of 0.01 Hz produces equivalent fatigue crack growth behaviour as obtained in in-situ fatigue tests under 35 MPa of hydrogen pressure. The appearance of the two fracture surfaces was identical in these two sets of tests..