Hot working behavior of duplex stainless steel UNS S32750 characterized by constitutive equations and processing maps

摘要

The hot deformation characteristics of duplex stainless steel UNS S32750 were studied in the temperature range of 900-1200°C and strain rate range of 0.1–10 s−1 by using hot compression tests. Flow stress was modeled by the constitutive equation of hyperbolic sine function. Processing maps for hot working were developed. The results reveal that the flow curves are nearly typical of DRX and DRV at low and high deformation temperatures where austenite and ferrite are dominant, respectively. In the processing map under stain of 0.7, a domain is centered at 1200 °C and 0.1 s−1, and the maximum efficiency is more than 36%. According to the maps, the zone with the temperature range of 1100-1200 °C and strain rate range of 0.1–-1s−1 may be considered as the optimum region for hot working.