Measurement of hydrogen permeation through structural steel sections of varying thickness at 19°C

Hydrogen permeation through four steel plates of varying thickness was achieved by simultaneously exposing one face of each plate to standard, sour corrosive conditions for periods of several days. A single representative structural steel had been used to mill the plates. The hydrogen flux at the opposing plate faces was measured using the hydrogen collection method. The work confirms that at low temperatures, hydrogen flux through a steel wall of greater than a few millimetres thickness is inversely proportional to thickness, all other factors being consistent. Furthermore, flux monitored from steel plate decayed approximately exponentially over the timescale of measurements, consistent with changing conditions at the steel entry faces. The work is of value in revealing how data generated by the probe fits with certain aspects of hydrogen diffusion and corrosion theory.