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S. Zamberger, P. Lang, E. Kozeschnik:
"Modeling the influence of atomic traps on H diffusion and solubility in steel";
Talk: 11th International Seminar "Numerical Analysis of Weldability", Graz (invited); 2015-09-27 - 2015-09-30; in: "Proc. 11th Int. Seminar on Numerical Analysis of Weldability", (2016), ISBN: 978-3-85125-490-7; 423 - 433.

Atomic traps heavily influence the diffusivity of interstitial hydrogen in steel. These can be solute atoms with attractive interaction energy to H, dislocations with their accompanying stress field, grain boundaries as well as precipitates and precipitate/matrix interfaces. Recently, a powerful model has been developed for prediction of the equilibrium segregation characteristics of interstitial and substitutional atoms to discrete atomic traps. The model is implemented in the thermokinetic software MatCalc. In this presentation, the model is briefly outlined and two recent applications are shown, one predicting the H trapping potential of NbC precipitates in steel as a function of austenitization conditions, the other demonstrating the prediction of long-range diffusion fields to characterize the H-permeation characteristics in corresponding experiments. With the latter approach, we also explain quantitatively the enormous spread of experimental H-diffusion coefficients reported in literature.