Mechanisms of the Attack of R - H Ladle Refractories by Iron - aluminum Alloys
이상갑Sang Kab Lee, 김성만Sung Man Kim
Abstract
Silica, magnesia-chrome and zircon bricks used in the R- H ladles of POSCO were made into crucibles, in which electrolytic iron and aluminium were maintained at 1600℃ for one hour under nitrogen atmosphere. The crucibles teated were cut into thin sections for optical microscopic and electron optic investigations to find the failure mechanisms of the different refractories in the prescence of the aluminium. Silica brick failed by the reduction of SiO₂ by Al added and the damage was aggravated by penetration of Al₂O₃ into brick. Attack of magnesia-chrome brick was characterized by spalling due to an anisotropy developed along the border outlined by penetration of the aluminium silicates into the crucible. Zircon brick remained almost intact due to ZrO₂ resulting from the decomposition of zircon and mullite formed as a reaction product of Al and refractory materials.