Creep behaviors evaluation of Incoloy800H by small punch creep test

In this paper, creep properties estimation of Incoloy800H under various loads and temperatures were performed experimentally and analytically. Compared to standard creep test, a similar creep character could be obtained by small punch creep test. On the basis of geometrical shape of deformed specimen, we proposed a modified geometrical model. The relatively simple yet accurate correlation between strain and small punch deflection was established. The reference stress under multi-axial deformation state was discussed and proved to be as constant at the identical condition. Additionally, to analyze the tertiary deformation and fracture mechanism of small punch creep test, creep damage tolerance factor was introduced and modified. The results indicated that necking and precipitate coarsening was the domain model in this phase. Meanwhile, the physical significance of three stages of deflection-time (D-T) curve was proved to be different with that of uniaxial creep curve.