Fracture behavior and microstructure analysis of Al2O3–MgO–CaO castables for steel-ladle purging plugs

• Published in: International journal of minerals, metallurgy and materials Vol. 23; no. 11; pp. 1333 - 1339
• Main Authors: Long, Bin, Xu, Gui-ying, Li, Yong, Buhr, Andreas
• Format: Journal Article
• Language: English
• Published: Beijing University of Science and Technology Beijing 01.11.2016; Springer Nature B.V; School of Materials Science and Engineering, University Science and Technology Beijing, Beijing 100083, China
• Subjects: Aluminum oxide; Calcium oxide; Castable refractories; Cement; Ceramics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Composites; Corrosion and Coatings; Corundum; Damping; Glass; Ladle metallurgy; Magnesium oxide; Materials Science; Metallic Materials; Microstructure; Modulus of elasticity; Natural Materials; Notch strength; Plugs; Purging; Room temperature; Shock resistance; Spinel; Steel making; Surfaces and Interfaces; Tensile strength; Thermal resistance; Thermal shock; Thermal stress; Thin Films; Tribology; copper oxide; alumina; microstructure; castables; thermal shock resistance; fracture behavior; magnesia
• ISSN: 1674-4799; 1869-103X
• DOI: 10.1007/s12613-016-1355-4

Three different castables based on the Al2O3–MgO –CaO system were prepared as steel-ladle purging plug refractories: corundum-based low-cement castable（C-LCC）, corundum-spinel-based low-cement castable（C-S-LCC）, and corundum-spinel no-cement castable（C-S-NCC）（hydratable alumina（ρ-Al2O3） bonded）. The fracture behavior at room temperature was tested by the method of 'wedge-splitting' on samples pre-fired at different temperatures; the specific fracture energy G′f and notched tensile strength σNT were obtained from these tests. In addition, the Young’s modulus E was measured by the method of resonance frequency of damping analysis（RFDA）. The thermal stress resistance parameter R′′′′ calculated using the values of G′f, σNT, and E was used to evaluate the thermal shock resistance of the materials. According to the microstructure analysis results, the sintering effect and the bonding type of the matrix material were different among these three castables, which explains their different fracture behaviors.