Intrastructural thermal stress is the main factor in the destruction of refractories in metallurgical furnaces
DOI:
https://doi.org/10.18321/cpc282Keywords:
Specific heat flux, periclase refractory, thermal stress, refractory structureAbstract
The work is devoted to the study of emerging temperature stresses at a temperature gradient under the influence of heat fluxes on refractory materials. The micro - and macro-level structural processes occurring in the material are investigated in the developed experimental setup. The paper studies the effect of thermal impulse flows in periclase refractories on the occurrence of vector stresses in the coastal layers from the working surface and internal structural elements. Macro and microstructural studies have shown that the intense heat fluxes and emerging temperature stresses contribute to the formation of structural defects and the rupture of intergranular bonds. Temperature stresses and variable loads arising during this process form complex structural elements in the material in the form of multi-dimensional blocks separated by pores. The results of electron microscopic studies of structural and phase changes under the influence of thermal impulse flows are presented. The layer-by-layer change in the internal structure and phase composition at temperatures from 500 to 1500 °C and the heating rate in the range from 5 to 45 °C/min is shown. The alteration in the phase composition in the intergranular and intergranular contacts of the material is superimposed on the thermal stresses arising under alternating loads, which can reduce stresses or increase them depending on the temperature. It is established that the alteration in temperature stresses depends on the phase changes in the thermal effect on the refractory properties.
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