EFFECT OF MICROSTRUCTURE ON THE EARLY STAGES OF CREEP DEFORMATION OF AN EXPERIMENTAL NICKEL BASE ALLOY.

Abstract

An experimental nickel base alloy similar to the wrought high-chromium alloy IN-597, is intended for use as blades and other stressed parts in gas turbine burners, but with a low carbon content to reduce carbide precipitation. The results of the creep tests carried out in the temperature range of 700-850 degree C, show that during primary creep deformation the strain data follow the Li equation derived for this stage and that the creep rate parameters, coefficient K//1 and minimum creep rate epsilon //m, can be related to the gamma prime precipitate particle morphology, dislocation motion mechanisms and grain boundary structures.