Effect of Carburization on Creep Performance of Cr35Ni45Nb Heat Resistant Alloy

The purpose of this paper is to describe the changes of the structure and the creep performance for Cr35Ni45Nb alloy after varying carburization. Carburizing layers with different thickness were produced in Cr35Ni45Nb alloy directly by vacuum carburizing experiment. The surface microstructure of Cr35Ni45Nb alloy was essentially changed after varying carburization. Creep performance of carburized only and carburization-creep treatment alloys were compared to study the effect of the carburization on creep for Cr35Ni45Nb heat resistant alloy. Mechanical properties of carburizing layer, carburizing transition layer and base alloy were characterized by micro-hardness, respectively. Results of creep rupture testing for the carburized and non-carburized specimens showed that carburization can influence the rupture time, failure strain and creep rate. Carburization also been proved to affect the constant of CMG and CMMG for different stress or carburizing level.