1993 Volume 34 Issue 6 Pages 483-488
The hydrogen trapping effects in Fe–Ti alloys were studied by repetitive electrochemical permeation measurements and gas pressure oscillating permeation measurements. A theoretical analysis has been made of the effects of both reversible and irreversible trapping sites on hydrogen diffusion using the Crank-Nicolson finite difference method. The break-through times are different for the first and second electrochemical polarizations in Fe–Ti alloys. The difference of the break-through times for the first and second polarizations is due to the irreversible trapping sites in the alloys, and the difference of break-through times in the second polarization for the alloys and pure iron is due to the reversible trapping sites. Taking the two different trapping sites with different binding energies into account, the effective diffusivity of hydrogen in Fe–Ti alloys at high temperature was also discussed.
