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 recrystalli- zation （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 ℃, recrystallization phe- nomenon 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--α （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.