65 Hydrogen Solubility and Trapping in AISI 316L Austenitic Stainless Steel

Hydrogen solubility and its interaction with vacancy-type trapping sites in AISI 316L austenitic stainless steel are studied by means of first-principles calculation and thermal desorption spectroscopy methods. It is found that hydrogen occupies preferably the octahedral positions in the lattice with the solution energy varying from 0.08 to 0.13 eV depending on its chemical environment. Hydrogen can be trapped by the vacancy, formation energy of which is dependent on its chemical environment manifesting the mean value of about 1.75 eV. The calculated energies of the hydrogen distribution over the octahedral positions of different chemical composition and its trapping are used in the interpretation of hydrogen thermal desorption spectra for the steel.