Electrochemical Aspects of Hydrogen Permeation in Iron at High Hydrostatic Pressure

摘要

A high pressure system containing an electrochemical method for continuous hydrogen permeation determination through metal foil is described for use at hydrostatic pressures up to 20,000 psi. The diffusion coefficient of hydrogen in Armco iron at 21C is 0.000043 sq cm/sec, unaffected by pressure up to 6200 psi; the solubility of hydrogen in Armco iron is a linear function of pressure up to a value of 7.8 x 10 to the minus 7th power mol H2/cc Fe at 6200 psi, 21C, and does not follow Sieverts' law behavior. By linking the hydrogen permeation current caused by cathodic charging with that caused by applied pressure, an overpotential-pressure relationship is obtained. (Author)