A novel experimental approach to investigate thermal shock damage in refractory materials

作者：Damhof F; Tesselaar W; van den Eynden J C

来源：CFI-Ceramic Forum International, 2007, 84(9): E75-E79.

A principal cause of premature failure of refractory materials in installations for iron- and steel making are fatal thermal stresses induced by high transient temperature gradients, a phenomenon also known as thermal shock. In coarse-grained refractory material this leads to various degrees of damage, ranging from a diffuse network of micro-cracks to localized macrocracking upon multiple thermal shock cycling. In order to simulate thermal shock at process conditions an experimental set-up has been developed. Molten aluminum is kept at a constant high temperature in an open induction furnace. Via a guiding system a refractory sample is brought into contact with the molten aluminum, providing an upward thermal shock. After the heating period the sample is exposed to ambient air, providing a downward thermal shock. From sound velocity measurements at various locations on the sample, before and after the experiment, the location-dependent damage could be determined. This enables use of the experimental results for future validation of a numerical damage model. From thermocouple measurements in the samples the experimental heat transfer conditions could be determined which enables the definition of the boundary conditions for the numerical modeling.

• 出版日期2007-9