Abstract
Micro-indentation technique was applied to evaluate the mechanical properties of corroded surface layers of Ni-alloy, 316SS, Ti and Ta, which were immerged into the corrosive gas environment consisting of HI+I_2+H_2O+H_2. It was simulated one of environments in the thermochemical hydrogen production, IS process, developed by JAERI. In particular, the degradation due to the corrosion attack by HI and the hydrogen embrittlement is a key issue from the viewpoint of material integrity in it. The micro-indentation tests using a spherical indenter and the inverse analyses with Kalman filter were performed to quantitatively estimate material constants of corroded surface layer. Ni-alloy exhibits good corrosion resistance and Ta is remarkably influenced by the hydrogen embrittlement.
