Molecular dynamic modeling of the biaxial strain effect on hydrogen solubility in BCC Fe using EAM potentials

The complex of negative effects of hydrogen on metal is termed hydrogen degradation. The processes of hydrogen degradation considerably depend on the characteristics of hydrogen diffusion and solubility in a specific material. Many manufactured articles keep their residual stresses during production (e.g. welded pipes and seams, supporting girders). In this case dependences of solubility and diffusivity of hydrogen on temperature and applied stress are of particular value for the prediction of hydrogen degradation. This paper presents the results of MD tests performed with Carter EAM potentials for the reproduction of general energy characteristics, namely hydrogen solution energy and diffusion barrier values, that are well examined with ab initio methods. The research on the relation between the hydrogen solution energy and the biaxial strain was also carried out. Of great interest is the capability of Carter potential to reproduce the hydrogen jump from tetrahedral to octahedral interstices of bcc Fe under the influence of the biaxial strains. Simulation results are compared with previous ab initio calculations and are in good agreement. Carter's potential B is capable of reproducing hydrogen transition from tetrahedral to octahedral interstices under biaxial stress.