Features of the fracture of refractory linings depending on the size of equipment

Using computer simulation, we studied the influence of the size factor on cracking in refractory linings by the example of steel-pouring ladles of ferrous metallurgy. The stress-strain state of the linings was analyzed at the macroscopic scale without taking into account their discrete structure (individual bricks) and the microstructure of the refractory material. We revealed that the maximum thermally and mechanically induced stresses in the linings are confined to certain regions associated with the design features of the equipment. Due to the distribution of mechanical loads and heat transfer features that regions become macroscopic stress concentrators. However, for small equipment size, these maxima are not sufficiently pronounced, and the stress fields formed by different stress concentrators overlap. Apparently, this is the reason for the relatively chaotic arrangement of cracks in the lining. In large equipment, the stress fields of «construction conditioned» concentrators do not overlap due to the large distance between them. The stresses in these concentrators exceed the background values in the surrounding regions of the lining by an order of magnitude or more. This determines the high probability of the formation of a characteristic fracture pattern with cracking in the vicinity of «construction conditioned» stress concentrators.