Structural and impurity traps for hydrogen atoms

Diffusion of hydrogen atoms has been considered taking into account structural and impurity traps. The structural traps are the crystal defects, and the impurity traps are alloying substitution impurities of a small atom radius. A comparative analysis of kinetics of the impurity segregation formation from the hydrogen atoms has been made for edge dislocation, microcrack tip and wedge disclination. As is shown, the wedge disclination captures the hydrogen atoms according to a linear law. The formation of the hydrogen segregations for the microcrack tip and edge dislocation runs slower. The hydrogen atoms’ diffusion in the cylindrical cladding with the impurity traps has been studied. The hydrogen atoms form complexes with the substitution impurities and retard their movement. After breaking down the complex, a hydrogen atom is free to migrate till it meets a new trap. Retardation of the diffusion process is observed at macroscopic scale. The relation for the field of the hydrogen atoms concentration is given taking into account the impurity traps. As is shown the hydrogen concentration in the medium with absorption is expressed in the solution of the corresponding task for free diffusion. The physical meaning of the obtained relations has been discussed.