Solid solution hardening of austenitic stainless steel crystals with high nitrogen content

A dislocation model is proposed, that describes the orientational and the temperature dependence of the critical resolved shear stress (CRSS) and the anisotropy of CRSS depending on the sign of the applied stress in single crystals of austenitic stainless steel with nitrogen impurities (interstitial atoms). This model explains that the solid solution hardening by the interstitial atoms is large in comparison to those by the substitutional atoms. The model takes account of the following: the change of the interstitial atom position in the lattice from octahedral interstice to tetrahedral site owing to passage of a leading Shockley's partial dislocation; the change in the separation width between two partial dislocations in external stress field; the relationship between the width of the extended dislocation and the elastic interaction of the extended dislocation with the impurity atoms.