Two dimensional joint distribution densities of mesodeformations and stress-strain state parameters in steel AISI-321

Basing on statistical distribution laws of first and second-level mesodeformations, we determined two experimental dimensional joint distribution densities of the deformation intensity and the Nadai-Lode stress parameter. The tests have been performed in two stages with uniaxial tension of a specimen made of AISI-321 steel up to 6 and 10 % residual plastic deformations. Components of the tensor for plastic mesodeformations and its statistics have been determined using the grade grid method. The grid size for the total amount of grains in the sample’s plane was 50 micrometers. Four large grains have been selected on the etched surface of the specimen. A grade grid of 10 micrometers size was applied to those areas. Afterwards, we have got histograms of two dimensional joint distribution densities of mesodeformations and the stress-strain state of the structural elements of the whole specimen and for particularly selected grains. Histograms help to determine probabilities of local overloads in mesostructures.