Advanced indentation technique for non-destructive evaluation on flow properties and residual stresses of nuclear power plant facilities

An advanced indentation technique has been developed as a potential method for non-destructive testing of in-field structures. This technique measures indentation load-depth curve during indentation and analyzes such mechanical properties related to deformation as yield strength, tensile strength and work-hardening index. Also the advanced indentation technique can evaluate residual stresses based on the concept that indentation load-depth curves are shifted with the direction and the magnitude of residual stress applied to materials. In this study, we characterized the flow properties and residual stress of the materials used in nuclear power plants using advanced indentation technique