Analytical evaluation of hydrogen induced stress in metal

A detailed study of hydrogen behaviour in the metal needs full analysis of the components of the stress-strain tensor field, induced by hydrogen atoms. Modelling of the stress-strain state of the “metal-hydrogen” system was carried out. From the standpoint of the theory of elasticity the appropriate system of basic key equations of the problem for determining stress components caused by hydrogen in metal, were formulated. Such equations were written for a cylindrical body. The plane deformation of a long cylindrical sample with the evident hydrogen concentration was investigated. Appropriate analytical ratios were established and theoretical analysis for the assessment of strain and stress tensor components caused by the concentration of hydrogen were also carried out. Calculation relations for a solid cylindrical sample were received. Computations of the stress tensor components induced by hydrogen in a solid cylinder during hydrogenation or dehydrogenation were done. Evidence of the uniform tensile zone within the cylindrical sample was stated during the sample hydrogenation, and near its surface - intensive compressive stresses. In contrast: during dehydrogenation an appropriate compression zone was evident in the sample while near the cylinder surface the tensile stresses were present.