Influence of the C content on the permeation of hydrogen in Fe alloys with low contents of C

Abstract

In this work, the permeability of hydrogen through samples of six Fe alloys was experimentally analyzed. The main objective of this work was to determine the influence of the C content of the alloy in the permeability of hydrogen. Three of the samples, pure Fe, FeP and Fe10%Cr, contained negligible quantities of C, whereas the other three, FeC, FePC, and Fe10%CrC, had the same metallurgical composition as their corresponding pair, with the only difference in the carbon content. The gas evolution permeation technique was used to measure the hydrogen transport parameter of permeability in these alloys. The experimental measurements were carried out with temperatures ranging from 423K to 823K and for high purity hydrogen loading pressures ranging from 1.0×103Pa to 1.5×105Pa. The experimental permeation results were analyzed using a non-linear least square fitting. The final resulting values of the permeability were paired off in order to determine the effect of the C content: pure Fe versus FeC, FeP versus FePC and Fe10%Cr versus Fe10%CrC. According to the results, the influence of the metallurgical composition of C in Fe alloys on the permeability of hydrogen is discussed together with the synergistic effects caused by the presence of P and Cr.

Keywords

• Permeability
• Hydrogen
• Tritium
• Iron alloy