The Study Of Physical Metallurgical Models For Type 304 Stainless Steel In Hot Rolling

Hot compression tests of type 304 stainless steel (0Crl8Ni9) were performed on GLEEBLE-3500 thermo-mechanical simulator to study the influence of deformation conditions such as initial grain size, temperate, strain, strain rate and inter-pass holding time to austenite recrystallization behaviors and flow stress curves.According to the quenched sample microstructure of different reheating temperature and soaking time and the true strain-true stress curves of hot compression tests within different reheating conditions, it had been proved that the effect of the initial austenite grain size on austenite recrystallization and flow stress curve was not significant. On the basis of one-hit and double-hit compression tests of 304 austenite stainless steel, the deformation activation energies for dynamic recrystallization, metadynamic recrystallization and static recrystallization was obtained respectively with linear and nonlinear regression. And the critical strain, Zener-Hollomon parameter, as well as models of the fraction of metadynamic recrystallization and the fraction of static recrystallization for the investigated steel were built. According to the obtained true strain-true stress curves and their deformation conditions, the types of flow stress were classified into work hardening, work hardening & dynamic recovery and work hardening & dynamic recovery & dynamic recrystallization. Furthermore, these three types of macro-type flow stress models were regressed respectively and most of the curves predicted by the models had good agreements with the experimental results.Above models were compiled into program codes and validations have been done with those experiment parameters, the results shown that the calculated values were close to that from the experimental results. Thus those physical metallurgical models achieved through tests and investigation ware integrated into the microstructure simulation and property prediction software system. A prediction was carried out with the onsite rolling parameters for type 304 stainless steel production of a domestic factory. The predicted results also showed that those models had good applicability.