| 摘要 |
PURPOSE:To improve the quality of a billet to the level equivalent to the continuously cast bloom having a large section in the production of a small section billet using an electromagnetic stirring technique for a low C molten steel by specifying the relation among the frequency of the AC to be conducted to an electromagnetic coil, the magnetic flux density at the coil center and the thickness of a solidified shell. CONSTITUTION:A molten steel is supplied to the inside of a casting mold lubricated with oil from a nozzle or by open stream, in continuous casting of a killed steel billet contg. <=0.20% C and having <=200mm. square sectional area. While the molten steel is electromagnetically stirred in the casting mold by the magnetic field in which the frequency f1 (Hz) of the AC to be conducted to the 1st electromagnetic coil complies with the inequality I and the magnetic flux density G1 (Gauss) at the coil center complies with the inequality II, the molten steel is continuously drawn below the casting mold. The AC is conducted to the 2nd electromagnetic coil in the intermediate period when the molten steel solidifies as a billet and the molten steel is electromagnetically stirred in the magnetic field in which the magnetic flux density G2 (Gauss) at the coil center is in the range of the inequality IV when thickness D2 (mm.) of the solidified shell is of the inequality III. |
