Abstract
A new process has been developed as a result of R & D effort to investigate and establish the feasibility of applying degassing technology to the molten steel to produce steels with low concentration of phosphorus, sulphur, oxygen and hydrogen.
The VOF process (namely Vacuum-Oxygen-Flux Process) consists basically of the following steps; (1) desulphurization during tapping of molten steel from an LD converter, (2) transferring the desulphurized liquid steel to a ladle during which slag is removed from the molten bath, (3) heating the molten steel in the RH vessel, (4) adding the flux of 1 : 1 mixture of lime and fluorite into an RH vacuum vessel for further desulphurization, degassing and deoxidation of the molten steel.
The new development has made it possible to reduce the sulphur content of steel down to approximately 0.002 percent, phosphorus content to 0.015 percent, oxygen content to 0.002 percent and hydrogen content to 0.00015 percent.
