Effect of indentation depth in impression creep test: conversion relationships and correction functions

The impression creep test method has been used extensively to determine the in-service properties of power plant components from a small volume material. In standardisation test, determination maximum ‘allowable’ indentation depth is an important issue. This paper presents results finite element analyses obtained using simplified based on steady-state creep, for evaluating variation conversion factors with depth. show that significant influence parameters and deformation rate when sufficiently large. On this basis, recommendation practical application these relationships was made users, empirical formulas were provided possible corrections factors. effect plastic zone due initial loading subsequent found be insignificant.