The relationship between the small-punch creep test and the conventional creep test was investigated experimentally using a method similar to that of the Monkman?Grant relationship. Uniaxial and small-punch creep rupture tests were carried out on 9Cr-2W ferritic steel(Commercial Grade 92 steel: X10CrWMoVNb 9-2) at elevated temperatures. From the relation derived in the same manner as the Monkman?Grant relation, a correlation between the displacement rate in response to the small-punch creep test and the strain rate in the uniaxial creep test was found, and the creep life was calculated using this relation. Furthermore, the failure modes of the small punch creep test specimens were investigated to show that the fracture was caused by creep.
