Creep deformation and damage mechanism of compact graphite cast iron with different pearlite contents

The creep deformation and damage mechanism of compacted graphite cast iron (CGI) with varying pearlite contents were studied at 450 degrees C, 500 degrees C, and 550 degrees C, with accompanying stress ranges from 40 MPa to 150 MPa. The creep deformation of CGI alloys presents obvious when the temperature exceeds 450 degrees C. The creep rate exponentially decreases with pearlite contents and the creep mechanism changes from dislocation slip to grain boundary sliding. There are (I) intergranular and transgranular cracks, (II) interfacial debonding between graphite and matrix, and (III) pearlite morphologic transforming in the microstructure of CGI during the creep test. (I) and (II) are mainly caused by the creep stress and temperature, and (III) may be related to plastic deformation. These cracks can interact with each other and accelerate the failure and fracture of materials.(c) 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).