Numerical study of creep effect on purging plug performance under cyclic service

The service life of the purging plug is one of the fundamental factors that determine the downtime and usage efficiency of the whole ladle. The creep behaviour of the purging plug was thus investigated to identify the possible failure mechanism. At first, the creep parameters of the Norton–Bailey strain hardening rule were inversely identified via the results of the creep test. Then, the thermal-solid coupling model approach was employed to predict the creep behaviour of the purging plug, in which the Norton–Bailey strain hardening rule was applied. The numerical results show that the temperature of the purging plug presents a cyclic trend after the first service period since the preheating temperature is lower than the temperature of molten steel. Furthermore, the distribution of the creep strain intensity in a layered form could also contribute to a gradual spalling of the purging plug end in service. Besides, the creep strain concentration around the slit can be responsible for the clogging of the purging plug.