Metadynamic Recrystallization Behavior of As-cast 904L Superaustenitic Stainless Steel

The metadynamic recrystallization (MDRX) behavior of as-cast 904 L superaustenitic stainless steel was investigated by double pass isothermal compression tests at temperatures of 950 — 1150 °C, strain rates of 0.05 — 5 s−1 and interval of 1 — 100 s. The effects of working parameters (deformation temperature, strain rate, pre-strain and interval time) on the flow curves and microstructural evolution were discussed. The MDRX fraction increased obviously with the increase of deformation temperature, strain rate and interval time. The MDRX softening was controlled by the migration of grain boundary, annihilation of dislocation and dynamic recrystallization. Moreover, the kinetic model was established for the prediction of MDRX behavior of as-cast 904 L superaustenitic stainless steel based on the experimental data. A good agreement between the predicted and the experimental values was achieved (correlation coefficient R2=0.98), indicating a satisfactory accuracy.