Abstract
In order to develop a methodology for creep life assessment of directionally solidifed Ni-base superalloy CM247LC, commonly used in advanced gas turbine blades, changes in electrochemical property of the alloy caused by creep have been investigated. Experimental results on electrochemical polarization measurements revealed that the peak current densities "Ip" and "Ipr", which appeared at a specific potential during potentiodynamic polarization reactivation measurements in a dilute glyceregia solution, increased linearly with the life fraction at an early stage of creep life and were uniquely correlated with a newly proposed Arrhenius-type parameter "(t/tr) exp (-Qc/RT)". The creep life fraction can be nondestructively evaluated by electrochemical polarization measurements and the above parameter.
