Creep rupture life and variation of micro-structure according to aging time and creep test methods

To investigate the effect of defects on the mechanical property of 9Cr–0.5Mo–1.8W–V–Nb (ASME-P92) alloy, creep rupture and small punch creep (miniaturized disc band) tests were performed. The precipitates and micro-cavities generated during the test periods were investigated quantitatively. To evaluate the characteristics of creep rupture, the relationship between the precipitates and growth of cavities was derived. Also the creep deformation characteristics and rupture time according to different aging times, test temperatures, stresses, and loads were investigated. The growth of micro-cavities according to the different load application methods, or different test methods was investigated by uniaxial creep and small punch creep tests.