Gas barrier for the refining superalloy

Abstract

The disclosure is made for the use of a hearth for receiving metals to be melted and exposing the molten metals to the furnace atmosphere with the upper surface of the molten metal free to float impurities such as oxides, carbides, or other undesirable materials on the upper surface of the molten metal or alloy. Gas jets blow an inert gas in one direction over the upper surface of the molten metal, generally parallel to the upper surface of the molten alloy. Thus, the gas jets remove impurities from the upper surface of the molten alloy by blowing or skimming the impurities off the top of the pool toward the walls of the hearth. The preferred position of the gas jets is in the notch of the hearth over which the molten alloy flows from the main body of the hearth into a withdrawal crucible. Moreover, the blowing gas under pressure does not cause appreciable loss of the molten alloy, and the gas jets, when blowing inert gas across the upper surface of the molten alloy, do not adversely affect the performance of a plasma torch above the hearth and operating to melt the solid alloy to a molten condition in the hearth.

Dependencies are inferred from the claim text.