Hot Working of High Nitrogen Austenitic Stainless Steel

With hot rolling in laboratory and Gleeble thermal simulator, the hot working of a high nitrogen austenitic stainless steel (HNASS) was researched. The results showed that dynamic recovery (DRV) and dynamic recrystallization (DRX) in HNASS occurred during hot working, and both of them had well-defined stress peaks in flow curves under different conditions. During hot rolling experiment at temperature from 950 to 1 050 °C, recrystallization phenomenon does not take place in test material until the deformation ratio is up to 40%. Recrystallization influences remarkably the strength and ductility of material, and the test HNASS possesses better combination of strength with ductility. According to the curve of θ—σ (strain hardening rate-steady state stress), the DRX critical strain of test material was determined. Also, the activation energy of hot working was calculated to be 746. 5 kJ/mol and the equation of hot working was obtained.