Purging plugs are widely used in the secondary refining process, and its service life determines the
downtime and usage efficiency of the whole ladle. This study focuses on comparing the heat transfer and
thermomechanical behaviour of purging plug with different slits to obtain the reason for the long service
life of purging plug by thermal-structure coupling method. The numerical results showed that the moderation
of temperature distribution is achieved by changing the slit shape and the reasonable arrangement
of the circular slits. Furthermore, the circular slits can alleviate the stress concentration phenomena, and
circular slits are better for decreasing the axial stress in the purging plug, which occurred at the position
located 0.323 m above the bottom face, and its distance from the centre is 0.04 m.