Creep life prediction of Ni-base superalloy used in advanced gas turbine blades by electrochemical method

In order to develop a methodology for creep life assessment of directionall y solidified Ni-base superalloy CM247LC, commonly used in advanced bras tur bine blades, changes in electrochemical property of the alloy caused bq cre ep have been investigated. Experimental results on electrochemical polariza tion measurements revealed that the peak current densities "I-p" and "I-pr" , which appeared at a specific potential during potentiodynamic polarizatio n reactivation measurements in a dilute glyceregia solution, increased line arly with the life fraction at an early stage of creep life and were unique ly correlated with a newly proposed Arrhenius-type parameter ''(t/t(r))exp( -Q(c)/RT)". The creep life fraction can be nondestructively evaluated by el ectrochemical polarization measurements and the above parameter.