| Research Abstract |
Nonmetallic inclusions included in metal products result in severe problems like slivers in thin plates, snapping of wires, and cracking in hard processing, therefore new methods by which inclusion-free products can be produced are strongly required. In this study, two investigations are made, one is to develop a separation method by using electromagnetic force, and the other is to propose electromagnetic flowing and stirring methods, which enhance agglomeration and separation of inclusions in the same time.
First of all, electromagnetic separation by simultaneous imposition of AC current and AC magnetic field was studied by a mercury-model experiment. This method was designed for the continuous casting process of steel as a tundish with inclusion separator. It was estimated that the inclusion particles larger than 30 μm could be separated perfectly by this separator in the condition of ordinary metal-producing rate.
High frequency magnetic field was also applied to the inclusion separat
… More
ion. Deoxidation rate of liquid steel by silicon was measured in a high frequency furnace, and the rate-controlling step was found to be the electromagnetic separation of SiO_2. To know the separation rate and the effect of mechanical stirring on the separation, experiments of SiC particle separation from liquid Al were carried out. Very fast separation was observed for 23 μm particle and the stirring rates required for preventing electromagnetic separation were determined. These results helped the Japanese national project of electromagnetic casting of steel to prevent inclusion accumulation in a initially solidified shell.
The separation force acting on particle has been evaluated theoretically only for a single sphere. In this study, a numerical analysis was made on the separation force and electromagnetically driven flow around two spheres. This study is thought to be the first trial to reveal the complex electromagnetic phenomena of inclusion swarm or clustered inclusions.
A new electromagnetic pump based on a twisted-rotating magnetic field was invented. Excellent performance was observed by the study using solid metal rods and liquid Ga. A new electromagnetic stirrer using similar principle with the pump was developed and its performance was verified by using liquid Ga. Less
|
