MULTISTAGE COMPRESSION OF MICROALLOYED STEELS - FE SIMULATION AND MEASUREMENTS OF GRAIN-SIZE

The objective of the project is to investigate the process of the multistage compression in application to the testing of the microalloyed steels. Theoretical part of the work is based on the thermal-mechanical finite-element model of the compression process. This model is connected with the conventional closed-form equations describing processes of recrystallization, precipitation and grain growth in the microalloyed steels. The experiment was performed on the hydraulic testing machine and it included both single- and multistage compression. The samples were air cooled or quenched after the deformation. The microstructure on the cross section of each sample was investigated and a comparison between the measured and calculated grain size was done.