Effect of Tantalum content on the low cycle fatigue properties of CLAM steel at 823 K

•The fatigue life initially decreased and then increased as the Ta content was increased from 0.027 wt% to 0.18 wt%.•The softening rate had declined with Ta content increased and the reduced softening rate was attributed to the increased number of Ta-rich MX particles.•The grain size and M23C6 were closely associated with the Ta content.•The crack distribution was quite sensitive to the Ta content.

The effect of tantalum (Ta) content on the low cycle fatigue (LCF) properties of CLAM steel at 823 K was investigated in this paper. Low cycle fatigue tests were carried out on four ingots of CLAM steel with Ta contents of 0.027 wt%, 0.078 wt%, 0.15 wt% and 0.18 wt%, respectively. The results showed that the fatigue life and softening behavior of CLAM steel were influenced by Ta content. The fatigue life initially decreased and then increased as the Ta content was increased from 0.027 wt% to 0.18 wt%. The softening rate had declined with Ta content increased and the reduced softening rate was attributed to the increased number of Ta-rich MX particles.