Evaluation of the dislocation density and dislocation character in cold rolled Type 304 steel determined by profile analysis of X-ray diffraction

The mechanical properties of Type 304 austenitic stainless steel change considerably on cold rolling at room temperature because of the formation of strain-induced α' martensite phase and work hardening induced by an increase in the dislocation density in the γ phase. In this study these two phenomena were investigated quantitatively by profile analysis of the X-ray diffraction. We show that the strengthening mechanism in cold rolled Type 304 steel changes with differences in the dislocation density between the γ and the α' phase. When the difference is large the mechanical properties of the steel depend on the volume fraction of the α' phase. On the other hand, when the difference is small the properties do not depend on the volume fraction of the α' phase but instead depend on the dislocation density and dislocation character in the γ phase.