Study on hot deformation behaviour of 316LN austenitic stainless steel based on hot processing map

316LN is a type of austenitic stainless steel whose grain refinement only depends on hot deformation. The true stress–strain curves of 316LN were obtained by means of hot compression experiments conducted at a temperature range of 900–1200°C and at a strain rate range of 0·001–10 s⁻¹. The influence of deformation parameters on the microstructure of 316LN was analysed. Both the constitutive equation for 316LN and the model of grain size after dynamic recrystallisation were established, and the effect of different deformation conditions on the microstructure was analysed. The results show that the suitable working region is the one with a relatively higher deformation temperature and a lower strain rate, in which the dynamic recrystallisation is finely conducted. Moreover, the working region that should be avoided during hot deformation was indicated.