Dynamic recrystallization behavior of an austenitic stainless steel for nuclear power plants

In order to study the effects of deformation conditions and initial grain size on the dynamic recrystallization behavior of316 LN austenitic stainless steel,single pass hot compression tests were conducted on a Gleeble-1500 D thermal-mechanical simulator with the deformation temperature of 900-1200℃,the strain rate of 0. 001-10 s^-1,the true strain of 0. 1-0. 9 and the initial grain size of 122-297 μm. It is obtained that the ratio of critical strain to peak strain and the ratio of critical stress to peak stress are 0. 38 and 0. 89,respectively. A dynamic recrystallization kinetic model and a grain size evolution model were established based on experimental data. In addition,the developed models were modified for DEFORM-3D finite element simulation. It can be found that the simulated values by the modified model and experimental data agree well,indicating that the modified models have good accuracy.