Characterization of thermal aging effects on the creep performance of T91 using small punch creep testing

摘要

This paper is concerned with the development and application of a small punch creep testing method for assessment of the effects of thermal aging and associated precipitate coarsening on the high temperature creep life and deformation behavior of a 9Cr ferritic-martensitic steel. The tests are conducted on P91 steel, for both aged (up to 1 year) and unaged specimens, at temperatures of 600°C. The unaged test results are shown to be consistent with previously published creep tensile test rupture life data in terms of Chakrabarty membrane stress. Aging is shown to have a significant, detrimental effect on creep life and deformation rate. The steady-state displacement rate, time to failure, and displacement at failure data, for both aged and unaged, were successfully correlated via the modified Monkman-Grant relationship.