Thermo‐chemo‐mechanical modeling of refractory behavior in service: Key points and new developments

Abstract

The lifespan of refractory results from a complex interaction between chemistry, thermal conditions, and mechanics. The development of numerical models able to predict the results of such complex multi‐physics couplings requires an intensive use of the thermodynamics of irreversible processes framework. Today, the main barriers to reach fully predictive simulations are: the access to relevant data at high temperature (chemical kinetics, chemical expansion coefficient, etc), the numerical complexity and the computational time. The theoretical framework is briefly illustrated on refractory lining applications with a focus on the impact of the swelling induced by corrosion. Then, the numerical difficulties to ensure the numerical convergence and the accuracy of the results when solving classical partial differential equations are examined. Finally, a new approach to model the capillary impregnation by slag, based on percolation theory, is proposed. The basics of this method and the first numerical results are presented.

Development and experimental characterization of the thermomechanical behavior of a scaled steel ladle

“…1,2 Normal operating conditions of these vessels include high temperatures, high thermal stresses, slag attack, and degradation of layers in contact with liquid steel. [3][4][5][6][7] Steel ladles are often built with multiple layers of refractory masonry linings enclosed within a thick steel shell to withstand such extreme operating conditions. [8][9][10] Each layer comprises refractory material with different thermal, mechanical, and chemical properties.…”

“…They are employed as industrial vessels to transport and refine molten steel and are exposed to a harsh operating environment 1,2 . Normal operating conditions of these vessels include high temperatures, high thermal stresses, slag attack, and degradation of layers in contact with liquid steel 3–7 . Steel ladles are often built with multiple layers of refractory masonry linings enclosed within a thick steel shell to withstand such extreme operating conditions 8–10 .…”

Computational homogenization of elastic-viscoplastic refractory masonry with dry joints

“…Refractory masonry with dry joints is extensively used for the linings of several high temperature components such as steel ladles, furnaces and rotary kilns due to their high thermal, mechanical and chemical stability, good thermo-mechanical and thermo-chemical properties [1][2][3][4][5]. When used in steel ladles, they are subjected to high thermal gradients, thermal shock, cyclic thermal heating and cooling, high thermo-mechanical stresses, slag attack, and harsh chemical environment [6][7][8][9][10][11].…”

“…Therefore, the lifespan of steel ladles internal linings is very short (several castings). Moreover, the design and optimization of these linings is still an engineering challenge due to the complex interaction between thermal fields, chemistry and the nonlinear mechanical behaviour of refractories at high temperature [1,6,12].…”

“…In addition, only one multi scale numerical model has been developed in the literature and it is suitable to simulate only the elastic or thermoelastic behaviour of the masonry. At high temperature, elastic models usually leads to overestimation of stress levels due to the elastic viscoplastic behaviour of refractories at high temperature [1,15]. More studies to understand the effects of joints, joints closure and reopening combined with viscoplasticity on the mechanical behaviour of refractory masonry linings at high temperature are required.…”