Behaviour of hydrogen, oxygen, and nitrogen in tap degassing process is studied and the efficiency of the process is found equivalent to the other processes. The degassing steps are divided into two parts. That is, the first is the birth and fall of droplets and the second is the degassing through the free surface of molten bath. The violent motion of the droplet at the first stage is very important. The applications to the desulphurization treatment, Al addition technique and the production of low carbon stainless steel, are also discussed.
