M. Reza Afshar, M. R. Aboutalebi, M. Isac, R.i.l. Guthrie,
Volume 28, Issue 1 (6-2009)
Abstract
In this research, a 3-D mathematical model is developed for simulating electromagnetic continuous removal of inclusions from molten metals. The model includes the computation of electromagnetic force field and fluid flow in the presence of electromagnetic forces. The results of flow field together with electromagnetic force field were further used for calculating the trajectory of inclusions in the molten metal. Parametric studies were performed to evaluate the effects of various parameters such as magnetic field intensity, inclusion size, and fluid velocity on inclusion removal efficiency in molten magnesium. In order to verify the mathematical model and visualize the trajectories of particles in the melt flow under electromagnetic force, a physical model was constructed. The predicted particle trajectories and separation in the physical model were compared with those obtained from experiments, which showed a relatively good agreement.
H. Tavakoli, M. Soltanieh, H. Aghajani, M. Jafarpour,
Volume 34, Issue 1 (5-2015)
Abstract
This study was intended to investigate the effect of injection of aluminium into the crystallizator on type, composition and activity of inclusions in low carbon steel grade USD7. The steel is made in Zob-e-Ahan Isfahan factory and its porosities and inclusions results in the problem of rupturing during rolling process. To improve the quality of this steel, 2.4 mm diameter pure aluminum wires were injected in to the crystallizator at the rate of 2, 4, 6 or 8 m/min in certain periods and then sampling was done. The results indicated that much of the added aluminum changed to aluminum oxide slag, and the remaining part altered the chemical composition of the inclusions. Increased aluminum caused an increase in the activity of alumina and reduction in the activity of other oxides in the slag and existing inclusions in the melt. By increasing Al2O3 activity from 0.313 to 0.649, the Al2O3 formation and oxygen exclusion probability increased in the system. Scanning electron microscopy showed that without aluminium injection, most of inclusions were FeO-MnO type placed around existing porosities in the ingot. The optimum rate of aluminum injection was found to be 4 m/min.
