Hydrogen Absorption of Commercially Pure Titanium in the Solution System NaCl-HCl

Abstract

Hydrogen absorption behavior of commercially pure titanium in the solution system NaCl-HCl has been studied in relation to corrosion by means of Glow Discharge Spectroscopy (GDS).
Results obtained are as follows.
(1) The hydrogen absorption layer on titanium formed by corrosion can be analyzed by means of GDS.
(2) When the passive film on titanium begins to break down in NaCl-HCl, hydrogen absorption can occur.
(3) The rate of hydrogen absorption is parabolic, indicating that hydrogen diffusion through the hydrogen absorption layer is rate controlling. The diffusion coefficient of hydrogen in titanium is 2.75-3.68 × 10^-12 cm²/s.
(4) X-ray diffraction patterns of the surface of hydrogen absorption layer show the presence of TiH₂.