Operating Principle and Plant Design of the VD/VOD Facility at ThyssenKrupp ACCIAI Speciali Terni (TK AST) for the Production of Superferritic Stainless Steel

摘要

The VD (Vacuum (Tank) Degassing) as well as the VOD (Vacuum Oxygen Decarburization) processes has been developed to carry out refining operations in secondary metallurgy outside the melting furnace. The VD/VOD system also offers the feature of performing all metallurgical process steps in one unit. At ThyssenKrupp Acciai Speciali Terni (TK AST) a new 150 t VD/VOD facility was commissioned in summer 2008. The product mix of this facility consists of several forging steel grades, but predominantly ferritic stainless steels including some superferritic grades, which are the subject of this paper. The paper will therefore deal with the following topics: