  From a general point of view, InterGranular Stress-Corrosion Cracking (IGSCC)
results from the interplay between mechanical loading and grain boundaries
opening. The former leads to intergranular stresses in polycrystalline
aggregates, the latter being either stress-accelerated or stress-induced. This
work aims at obtaining intergranular normal stress distributions in uncracked
polycrystalline aggregates, which is considered as a key milestone towards
IGSCC initiation predictive modelling. Based on the finite element method,
numerical simulations have been performed on Voronoi polycrystalline aggregates
considering a wide variety of material constitutive equations: crystal
elasticity (cubic and hexagonal symmetries) with different anisotropy ratios
and crystal plasticity for different sets of slip systems under the assumption
of uniform critical resolved shear stress: Face-Centered Cubic (FCC),
Body-Centered Cubic (BCC) and Hexagonal Close Packed (HCP) with or without
hardening, and for both uniaxial and equibiaxial macroscopic loading
conditions. In the elastic regime, a correlation between standard deviations of
intergranular normal stress distributions and a universal elastic anisotropy
index proposed recently is found and explained through a simple model. For
macroscopic strain larger than the yield strain, the evolution of standard
deviations with strain is rationalized by accounting only for the macroscopic
elastic strain and the standard deviation of Taylor factor. These numerical
results associated with physically-based simple models allow to estimate easily
intergranular normal stress concentrations, constituting a tool for classifying
polycrystalline aggregates according to their potential susceptibility to
IGSCC.
