  A model has been developed which simulates the deformation of single crystal
austenitic stainless steels and cap-tures the effects of hydrogen on stress
corrosion cracking. The model is based on the crystal plasticity theory which
relates critical resolved shear stress to plastic strain and the strength of
the crystal. We propose an analytical repre-sentation of hydrogen interactions
with the material microstructure during deformation and simulate the effects
hydrogen will have on void growth prior to fracture. Changes in the mechanical
properties of the crystal prior to fracture are governed by the interaction of
hydrogen atoms and ensembles of dislocations as the crystal plastically deforms
and is based on the hydrogen enhanced localised plasticity (HELP) mechanism.
The effects of hydrogen on void growth are considered by analysing the effect
of hydrogen on the mechanical property of material bound-ing an embedded void.
The model presented has been implemented numerically using the User Material
(UMAT) subroutine in the finite element software (ABAQUS) and has been
validated by comparing simulated results with experimental data. Influencing
parameters have been varied to understand their effect and test sensitivities.
