| Abstract: | Influence of plastic deformation on the hydrogen diffusivity and solubility in austenitic Fe- and Ni-basic alloys The measurements of diffusivity and solubility were performed on as received and up to 50% cold worked high alloyed austenitic materials Inconel 600, Inconel 690, Incoloy 800 and AISI 321 by means of an electrochemical permeation method and a hydrogen determination technique (LECO RH 402). With increasing nickel content of the materials the hydrogen diffusivity increases whereas the activation energy of diffusion and the hydrogen solubility decrease. A marked change of the diffusion behaviour is observed in the case of cold worked samples depending on the alloy composition. An increase of diffusivity by about two orders of magnitudes was measured for AISI 321 as a result of α-martensite transformation. The cold working of the other alloys results in a decrease of the diffusivity by a factor of 2.7 maximally and a higher hydrogen content after effusion of the solved hydrogen. This refers to a higher hydrogen trapping. It is assumed that hydrogen atoms are trapped at the cores of dislocations and at microcracks formed during charging. |
