Effect of Al antioxidant in MgO–C refractory on the formation of Al₂O₃-rich inclusions in high-carbon steel for saw wire under vacuum conditions

Abstract

Al₂O₃-rich (>70 wt-%) inclusions generally hard and non-deformable are extremely detrimental for saw wire. In order to explore the source of this type of inclusion and provide solutions, experiments on the interaction between Al-containing MgO–C refractory and high-carbon steel for saw wire was conducted on a laboratorial scale using a cold crucible levitation melting furnace under vacuum conditions. [Al]_S (acid-soluble Al), [C] and [Mg] concentrations in steel, Al₂O₃ concentration in inclusions and microstructure of refractory/steel interface, etc. were analysed to clarify the influence of vacuum pressure, refractory addition amount and interaction time. Based on the experimental results and thermodynamic calculations, a presumable impact mechanism of Al antioxidant in MgO–C refractory on the formation of Al₂O₃-rich inclusions in high-carbon steel for saw wire under vacuum conditions was deduced, which in turn provided a reference for the control of Al₂O₃-rich inclusions in high-carbon steel for saw wire.

Keywords:

• Al₂O₃-rich inclusions
• Al-containing MgO–C refractory
• High-carbon steel for saw wire
• Al antioxidant
• Refractory/steel interaction