Creep damage parameters based on the distribution of cavities on grain boundaries

When polycrystalline heat-resistant steels are subjected to static or cyclic loading at high temperatures, they can exhibit various fracture modes and processes. This paper begins by outlining representative methods for life assessment under creep-dominated conditions. It then discusses the fracture processes and the underlying mechanisms. Under creep-dominated conditions, the initiation and growth of cavities serve as the primary form of material damage, making their quantitative assessment essential. Several parameters have been proposed to evaluate cavity distributions quantitatively. However, the relationship between these parameters and the actual cavity distribution in materials, as well as their physical significance, has remained unclear. In this study, a simple cavity distribution model was employed to clarify these issues. The results suggest that the area fraction of cavities is an appropriate damage evaluation parameter for transgranular fracture, while the fraction of cavities on grain boundary line is suitable for intergranular fracture.

This is an Accepted Manuscript of an article published by Taylor & Francis in Materials at High Temperatures on 13 Oct 2025, available at: https://doi.org/10.1080/09603409.2025.2567450.

This fulltext file will be available in Oct. 2026.