The permeation of H through, and H desorption from, duplex stainless steel membranes with various thicknesses were studied by using electrochemical techniques. During the experiments, one side of a membrane was charged with H by galvanostatic cathodic polarization in 0.1M NaOH at 25C. After interrupting H charging, the H desorption rate was measured on both sides of the membrane. The resultant permeation and desorption rates were analyzed in terms of the real values of the H diffusivity and the lengths of the diffusion paths in the ferrite phase. The total amount of absorbed H consisted mainly of H dissolved in the ferrite matrix (diffusible H) and H dissolved in the austenite phase (reversibly trapped H).

Electrochemical Investigation of Hydrogen Absorption in a Duplex Stainless Steel. T.Zakroczymski, E.Owczarek: Acta Materialia, 2002, 50[10], 2701-13