| 摘要 |
A body of partially solidified metal emerging as ingot from the exit end of an open-ended mold, is direct cooled by discharging liquid coolant onto the surface of the ingot through a passage of the mold opening into the exit end of the mold at an aperture therein; and at times, such as in the butt-forming stage, by the added step of forcing pressurized gas into the coolant through a body of solid but porous, gas-permeable material incorporated into the wall of the passage at a surface thereof which extends generally parallel to the flow of coolant in the passage and coterminates with the exit end of the mold at the aperture to form an edge thereof. When the gas is added, the coolant discharges through the aperture in a discontinuous liquid phase in which it is laden with bubbles of undissolved gas that will alter the heat transfer characteristics of the coolant on the surface of the ingot to vary the rate at which heat is lost therefrom. |
