Kinetics and Critical Conditions for the Initiation of Dynamic Recrystallization in 304 Stainless Steel

Abstract

Commercial 304 austenitic stainless steel was deformed in compression at high temperatures (800 to 1280°C) and at strain rates from 0.001 to 1 s⁻¹. The critical and peak strains associated with dynamic recrystallization were determined based on changes in the work hardening rate as a function of the flow stress. The effect of the deformation variables (T, ε) on these values is analyzed; it is shown that over a range of temperature corrected strain rate (Z=10¹⁴ to 10¹⁶ s⁻¹, Q_def=405 kJ/mol), the initiation of dynamic recrystallization is delayed. This retardation is attributed to the segregation of substitutional impurity elements, principally phosphorus, to the sub-boundaries of the newly-forming DRX grains.