Creep Fracture and Creep Crack Growth in Inconel 718 Nickel basedSuperalloy

摘要

The purpose of this investigation is to explore the creep rupture behaviour and creep crack growth of hot workedrnby forging Inconel 718 nickel based superalloy. Included in this study are the general crack growth characteristic andrnthe relationship between the properties of smooth and notched specimen.rnIn order to investigate the creep deformation process, and the factor controlling the creep and the fracturernbehaviour, creep test has been carried out at 687 ℃ on specimen having longitudinal and transversal orientation withrnthe temperature controlled to ±1 ℃ and at various constant loads below and close the material yield stress. Moreoverrncreep crack growth test have been performed at the same temperature on 1/2 inch compact tension specimen havingrntransversal orientation.rnThe comparison of the creep tests and creep crack growth tests allow us to observe that the sample orientation isrna quite important factor influencing the crack behaviour.