Microstructure characterisation of Fe-21Cr-15Ni-Nb-V non-magnetic austenitic stainless steel during hot deformation

Hot deformation behaviour of Fe-21Cr-15Ni-Nb-V stainless steel was investigated by isothermal compression in the temperature range of 950-1150 degrees C with a strain rate of 0.01-10 s(-1). The results showed that complete recrystallisation occurred beyond 1050 degrees C, resulting from the pinning effect of (Nb, V)(C, N). The nucleation of dynamic recrystallisation (DRX) was performed by the bulging, sub-grain swallowing and twinning mechanism. With increasing strain rate, new twinning was transformed into the Sigma 3 regeneration mechanism in the partial DRX region, while an opposite transformation was observed in the complete DRX region. in the partial recrystallisation region, grain rotation resulted in the formation of < 110 > orientation. In the complete recrystallisation region, the texture tended to distribute randomly at a high strain rate, and the grain growth was accompanied by the emergence of stable < 100 > orientation. [GRAPHICS] .