Hydrogen localization under thermal gradients in hydride forming metal

Migration of hydrogen and hydride formation under thermal gradient leads to hydrogen redistribution in certain metals. A computational method for hydrogen localization in such metals is presented. We utilize hydrogen mass flux under temperature gradient to determine hydrogen distribution both in solid solution and in the hydride phase in a two-dimensional setting. Hydrogen precipitation to hydride is determined by a solid solubility relation, a function of the formation energy, which is treated as a stochastic variable subject to fluctuations. Einstein’s fluctuation theory is adapted to calculate the spatial distribution of hydrogen in solid solution and in the hydride phase. Hydrogen concentration gets localized in the colder region of the body. We apply the model to the case of a zirconium alloy, which is a material for fuel cladding utilized in pressurized water reactors. Cladding continuously picks up hydrogen during service. Our results, hydrogen concentration profiles are comparable to observations