High-temperature tensile strength of alumina-spinel refractory by Brazilian test at 1200°C coupled with DIC in-situ monitoring.

This study investigated for the first time the corrosion effect of Al 2 O 3 -MgAl 2 O 4 refractory by steel ladle slag using a DIC-coupled Brazilian test at 1200 °C. Three types of alumina-spinel materials were used in the test, namely, original non-infiltrated refractory, slag-infiltrated at 1450 °C as well as postmortem refractory after 69 cycles of work in the sidewalls of steel ladle. Lab infiltration was conducted at 1450 °C using CaO-Al 2 O 3 -SiO 2 -based ladle slag and its analog enriched with manganese (10 % MnO). The tensile strength of postmortem material at 1200 °C was the highest at 10.7 MPa, and it was 52 % and 70 % higher than for reference and MnO-enriched slag, respectively, and 80 % higher than for original refractory. The significantly raised tensile strength of slag-infiltrated materials vs. original non-infiltrated brick was directly related to the densification of microstructure by corrosion products (mainly CA 6 , CA 2 , Fe) which caused the infiltrated materials to be stiffer and with a more brittle nature to fracture. • DIC-coupled Brazilian test at 1200 °C of corroded material was tested for the first time. • Original, lab-infiltrated and post-mortem Al 2 O 3 -MgAl 2 O 4 refractory was tested. • Post-mortem brick had almost 80 % higher tensile strength than the original brick. • Corroded materials were revealed to fracture more brittle than the original brick. [ABSTRACT FROM AUTHOR]