Optimization of hot workability in stainless

Abstract

The hot working behavior of 304L stainless steel is characterized using processing maps developed on the basis of the Dynamic Materials Model and hot compression data in the temperature range of 700°C to 1200°C and strain-rate range of 0.001 to 100 s^-1. The material exhibits a dynamic recrystallization (DRX) domain in the temperature range of 1000°C to 1200°C and strain-rate range of 0.01 to 5 s^-1. Optimum hot workability occurs at 1150°C and 0.1 s^-1, which corresponds to a peak efficiency of 33 pct in the DRX domain. Finer grain sizes are obtained at the lower end of the DRX domain (1000°C and 0.1 s^-1). The material exhibits a dynamic recovery domain in the temperature range of 750°C to 950°C and at 0.001 s^-1. Flow instabilities occur in the entire region above the dynamic recovery and recrystallization domains. Flow localization occurs in the regions of instability at temperatures lower than 1000°C, and ferrite formation is responsible for the instability at higher temperatures.