Lance for decarburising stainless steel - consists of three concentric pipes down which are blown oxygen, carbon dioxide and steam

摘要

A refractory coated, immersion lance for treating a quality steel melt, esp. stainless steel, in a ladle under vacuum, consists of three concentric pipes of different dias. The inner pipe and the two annular passages are each connected to a fluid source. The inner pipe is pref. connected to a steam supply, the middle annulus to an O2 supply and the outer annulus to a protective medium, esp. an endothermically reacting gas (pref. CO2). Also claimed is a method of decarburising quality steel melts using the lance, in which, as soon as the C in the melt reaches the required level, argon is substituted for the gases used during refining to purge the system and gradually relieve the vacuum.