Microstructure and Deformation Behavior of Nitrogen Bearing Austenitic Steels Evaluated by Neutron Scattering Analyses

Abstract

Small angle neutron scattering (SANS) and in situ neutron diffraction during tension test were performed for three austenitic stainless steels with different concentrations of nitrogen. The existence of nano-sized cluster composed of nitrogen and alloy element atoms is suggested by SANS. The cluster seems to make dislocation line planar and hinder cross slip. Because of such a characteristic dislocation motion, the stress relaxation at the grain boundaries becomes difficult leading to enlarge the intergranular stress in nitrogen bearing steels. The in situ neutron diffraction reveals clearly that the intergranular stress increases with increasing of nitrogen concentration.