Vacuum degassing is practiced in the steel industry as under :
Vacuum degassing processes of molten steel to a low-pressure environment to remove gases (chiefly hydrogen and oxygen) from the steel. The effectiveness of any vacuum degassing operation depends upon the surface area of liquid steel that is exposed to low pressure. The mechanisms of hydrogen and oxygen removal from liquid steel are related directly to surface area.
Hydrogen removal is a diffusion and partial pressure phenomenon. Oxygen removal is a function of chemical reaction of oxygen with carbon and the partial pressure of carbon monoxide.
The processes of degassing treatment : composition and temperature control; decarburization; micro cleanliness; and inclusion morphology. Under the vacuum degassing treatments three processes which primarily use this treatment are stream degassing, recalculation degassing and vacuum degassing in the ladle can posible.