Identification of processing parameters for Fe-15Cr-2.2Mo-15Ni-0.3Ti austenitic stainless steel using processing maps

The processing parameters for hot working of Fe - 15Cr - 2.2Mo - 15Ni - 0.3Ti austenitic stainless steel (alloy D9) are identified using processing maps developed on the basis of the dynamic materials model and hot compression data in the temperature range 850-1250 degreesC and strain rate range 0.001-100 s(-1). The efficiency of power dissipation increased with increase in temperature and decrease in strain rate. Dynamically recrystallised microstructures resulted when the efficiency of power dissipation was in the range 27-37%, i,e, in the temperature range 1050 - 1250 degreesC and strain rate range 0.001 - 0.5 s(-1). Flow localisation occurred in the regions of instability at temperatures lower than 1000 degreesC and at higher strain rates. The dynamic recrystallisation regime observed in this alloy is compared with other austenitic stainless steels, namely, AISI type 304L and 316L. (C) 2001 IoM Communications Ltd.