Sammendrag
ABAQUS FE simulations of hydrogen diffusion in duplex stainless steel have been performed.
Three models with different ferrite-austenite configurations have been applied and the hydrogen
diffusion and the hydrogen coefficient have been evaluated as a function of austenite
phase size and shape and the calculated diffusion coefficients compared to literature. Hydrogen
concentration due to stress and plastic strain close to an embedded flaw has also been
evaluated. An important observation is that the simulations show that when the austenite phases
are saturated with hydrogen there is no large difference in the overall diffusion rate between
the small and large phased models, i.e. no influence of tortuosity is observed. The work clearly
demonstrates that both microstructure and flaws will influence the hydrogen diffusion and the
hydrogen concentration and hence, must be taken into account when evaluating the susceptibility
of hydrogen stress cracking in duplex stainless steels.
Three models with different ferrite-austenite configurations have been applied and the hydrogen
diffusion and the hydrogen coefficient have been evaluated as a function of austenite
phase size and shape and the calculated diffusion coefficients compared to literature. Hydrogen
concentration due to stress and plastic strain close to an embedded flaw has also been
evaluated. An important observation is that the simulations show that when the austenite phases
are saturated with hydrogen there is no large difference in the overall diffusion rate between
the small and large phased models, i.e. no influence of tortuosity is observed. The work clearly
demonstrates that both microstructure and flaws will influence the hydrogen diffusion and the
hydrogen concentration and hence, must be taken into account when evaluating the susceptibility
of hydrogen stress cracking in duplex stainless steels.