Hydriding and cracking behavior of titanium under cathodic polarization conditions

Hydride formation of titanium in both 0.1 M sulfuric acid (H₂SO₄) solution and artificial seawater under cathodic polarization has been investigated. The hydride formed in titanium was identified by x-ray diffraction, light and electron miscroscopy. Precipitation of titanium hydride has been observed to take place not only in sulfuric acid but also in artificial seawater of pH 5.0 and 8.2. The absorption of hydrogen by titanium could lead to premature failure in either 0.1 M sulfuric acid or artificial seawater (pH 8.2). Hydrogen-assisted cracking in these environments was observed only at an initial applied stress greater than 294 MPa.