| 摘要 |
PURPOSE:To prevent an increase of inclusions and to evade a breakout accident by limiting a range of magnetic field of a static magnetic field generator provided in a pouring direction from a bottom end of a single hole type submerged nozzle, and an intensity of a magnetic flux density to brake the molten steel flow from a delivering gate. CONSTITUTION:The static magnetic field generator 5 is positioned to magnetize statically for the pouring molten steel in the range of 20-30mm for advancing position from the delivering gate 3 of the single hole type submerged nozzle 2. Then, a length of the static magnetic field generator 5 is regulated to the same or more than a min. length of a section of the casting billet, and the magnetic flux density is regulated to >=1,200 gauss at the center of a mold 1. Here, the reason why the range influenced by the magnetic field is limited, is that non-metallic inclusions are easily trapped into the casting billet, as the amount of molten steel flowed to downward is increased, in case of shorter length than above-mentioned length for the static magnetic field generator. Furthermore, if the magnetic flux density is not >=1,200 gauss, the amount of non-metallic inclusions is increased as the molten steel flowed to downward is not braked. |
