Wear-resistant castables are subject to collision, erosion, and wear by high-concentration particles at high temperatures, and different situations will occur, especially large-scale collapse, cracks, and cracking of existing wear-resistant castables.
Problems during the use of wear-resistant castables
1. The expansion coefficient of wear-resistant and refractory castables is different from that of steel, and its expansion and contraction cannot be synchronized with external steel. When the expansion joints reserved for wear-resistant castables cannot compensate for the expansion of the boiler, the extrusion between the wear-resistant materials will collapse.
2. The internal anchors of the wear-resistant castable are made of heat-resistant steel, which has poor temperature resistance. It will be carbonized and fractured in high-temperature flue gas for a long time, resulting in large-scale collapse of the wear-resistant material: the quality of the construction furnace is poor, and the wear-resistant castable contains high water content, which will cause ignition. Then it is converted into water vapor. When the steam pressure exceeds the tensile strength of the wear-resistant castable, it will cause the lining layer to explode, causing the furnace wall to collapse after ignition: The collapse factors of the wear-resistant castable are related to the thermal shock stability of the material, and the furnace temperature sharply It also collapses when it changes.
3. The wear-resistant castable is in direct contact with or includes metal parts. In the case of temperature fluctuations, cracks will appear in the wear-resistant castable during operation due to the different thermal expansion coefficients of metallic and non-metallic materials. In addition, due to temperature fluctuations, the wear-resistant castable is subject to great internal stress. When the internal stress exceeds the resistance of the wear-resistant castable, fatigue cracks will occur. After the crack propagates, the castable will also crack.
In the process of using wear-resistant castables, cracks are inevitable. Different measures can be taken to reduce the formation of cracks, prevent the occurrence of through cracks, and terminate the expansion of cracks.