Purging plugs employed in ladles in the steel industry undergo severe thermomechanical loads owing to the cyclic operations, including preheating, transporting, stirring, and holding stages. For the smooth running of the process with less downtime, the lifespan of the purging plug needs to be aligned with the overhaul interval without failure. In the present study, to identify the thermomechanical failure mechanisms of corundum castable purging plugs with different slit structures via a quantitative evaluation method, the Drucker–Prager material constitutive model was applied to account for the irreversible behavior. The results indicate that both shear and tensile failure occur in the purging plug with rectangular slits, where the shear failure dominates in the middle of the holding stage and tensile failure appears during the stirring stage. Moreover, the premature shear failure occurs in the upper section near the working face for both types of purging plugs. The application of circular slits diminishes the stress concentration in the purging plug and changes the fracture mechanisms, extent, and occurrence time, which experience mere shear failure in the early stage of transportation.

由于循环操作，包括预热、运输、搅拌和保持阶段，钢铁工业钢包中使用的吹扫塞承受严重的热机械负荷。为了过程的平稳运行和更少的停机时间，吹扫塞的寿命需要与大修间隔保持一致，不会出现故障。在本研究中，为了通过定量评估方法确定具有不同狭缝结构的刚玉浇注料吹扫塞的热机械破坏机制，应用 Drucker-Prager 材料本构模型来解释不可逆行为。结果表明，矩形狭缝吹扫塞同时发生剪切和拉伸破坏，其中剪切破坏主要发生在保温阶段的中间，而拉伸破坏出现在搅拌阶段。此外，对于两种类型的吹扫塞，过早剪切破坏都发生在靠近工作面的上部。圆形狭缝的应用减少了吹扫塞中的应力集中，改变了断裂机制、程度和发生时间，在运输早期仅经历剪切破坏。