抄録
Small Punch (SP) creep test has been recognized as a practical procedure to examine creep rupture lives only sampling a very small volume. However the standard test method of SP creep has not been established yet. In this study, SP creep tests in air and in vacuum were carried out at 600℃ employing 2.25Cr-1Mo Steel and using two types of loading balls which vary in a diameter of 2.0mm and 2.38mm. As a result, creep rupture lives with the loading ball of 2.38mm in diameter were longer than these with that of 2.0mm. On the other hand, there were little difference among the test results in lower applied load levels in air and in vacuum regardless of the loading ball diameter. Ratio of applied load in the SP creep test to stress in the uniaxial creep one was changed from 1.7 to 2.0mm^2 with the loading ball of 2.0mm and from 2.1 to 2.2mm^2 with these of 2.38mm.
