To provide a degassing method for a molten aluminum alloy, capable of reducing hydrogen contents contained in an ingot of aluminum alloy to 0.1 ml/100 gAl or below, and further reducing a consumption quantity of chlorine gas and/or a chloride flux.
Degas-refining is carried out by treating an aluminum alloy with the chlorine gas and/or the chloride flux in a furnace, and further blowing fine bubbles of inert gas into the molten aluminum alloy out of the furnace. A hydrogen concentration in the molten aluminum alloy is reduceed to be 0.2 ml/100 gAl or below by the degas-refining in the furnace, or to be 0.1 ml/100 gAl or below by the degas-refining out of the furnace wherein the inert gas is arranged to be fine bubbles having a diameter of 20 mm or below by a mechanical shearing stress.
OSUMI KENJI
NAGAKURA YUTAKA
