Intergranular strains in Inconel-600 steam generator materials

Engineering components are inhomogeneous on the scale of the grain size since the grains generally have different elastic and plastic properties depending on their crystallographic orientations. Constitutive equations describing the mechanical properties of materials in terms of the deformation state of the grains within it are needed to describe the behaviour of structures using the finite element method. Neutron diffraction provides a test of such constitutive models as the elasto-plastic self-consistent (EPSC) model, because the elastic strains in all grain orientations inside a sample can be measured independently. In this paper the intergranular strains measured in tensile test coupons after uniaxial plastic deformation of +5.6% and -6.0% are presented as strain pole-figures for the (111), (002), (220) and (113) reflections of the FCC structure. The results are compared with the predictions of the EPSC model, which has no adjustable parameters. (orig.)