Computer simulation of microstructures evolution for three-high cross-rolling of hollow steels
Based on the rigid-plastic finite element method (FEM), an investigation on three-high cross-rolling of hollow steels was carried out in this study. The numerical model coupled thermal, mechanical and microstructural phenomena, in which some empirical recrystallization mode were obtained using the Gleeble-3500 thermomechanical simulator. The distributions of different field-variables, including temperature, strain and grain size, were obtained by FEM simulation. After different mandrel diameters were calculated, the investigation obtained the effect of microstructures evolution and compared the grain size between no mandrel and different mandrel diameters.
Prediction of microstructural evolution and recrystallization behaviors of a hot working die steel by FEM
Abstract A numerical analysis was performed to predict flow curves, and dynamic and static recrystallization behaviors of a hot working die steel (0.36% C, 1.1% Mn and 1.21% Cr) based on results from hot compression tests. The hot compression tests were carried out in a temperature range and strain rate of 950–1150 °C and 0.01–1.0 s−1, respectively. The modeling equation for flow stress was a function of strain, strain rate and temperature. In the modeling equation, the effects of strain hardening, recrystallization and grain growth were taken into consideration. Models for predicting the evolution of microstructure in die steel during thermomechanical processing were developed for dynamic and static recrystallization and grain growth phenomena. The microstructure model was combined with finite element modeling to predict microstructure development. Predicted microstructure is consistent with results obtained in multiple compression tests.
Trends in kiln drives
The heart of the cement plant is the rotary kiln, and continuous quality production of cement clinker depends on the continuous accurate performance of the rotary kiln drive.