Investigation of the Plastic Failure of Purging Plug with Circular Slits in Its Service

Abstract

狭缝式透气塞在钢包精炼中得到广泛的运用，其使用寿命决定了整个冶炼周期的停机时间和冶炼效率。为了延长透气塞的使用寿命，其服役过程中的热机械行为的研究变得尤为重要。在合理的简化透气塞服役过程的边界条件后，分别采用线弹性模型和弹塑性模型得到透气塞服役过程中的瞬态热机械应力分布。通过对比两种模型下的热应力发现，在长期循环服役的过程中，透气塞容易产生周期性疲劳；此外在吹氩期间透气塞内部r = 0.04 m，y = 0.32 m附近容易发生是拉应力损毁；而且，在圆孔透气塞的实际使用过程中的损毁现象与弹塑性模型下损毁预测较为吻合。 Purging plug with slits was widely used in secondary metallurgy, and its service life determines the downtime and usage efficiency of the whole ladle. For achieving long service life, the ther-momechanical behaviour analysis of purging plug is of great importance. The linear elastic model and the elastic-plastic model are employed to obtain the transient thermo-mechanical stress distribution of the purging plug simplifying the boundary conditions of the service pro-cess of the purging plug. By comparing the thermal stress of the two models, it is found that in the process of long-term cyclic service, the purging plug is prone to periodic fatigue. In addition, tensile stress damage of purging plug will happen near r = 0.04 m and y = 0.32 m during the stir-ring process. Moreover, the damage phenomenon in the actual use that located around the slits is more consistent with the damage prediction under the elastic-plastic model.