Characterization of residual stresses in bent incoloy-800 tubing by neutron diffraction

Neutron diffraction measurements of intergranular strains in MONEL-400

“…Measurements of residual strains in bent INCOLOY 800 steam generator tubes [2] gave a clear example of this effect. Similar behavior is shown for bent MONEL* 400 steam *INCOLOY and MONEL are trademarks of INCO Alloys International, Huntington, WV.…”

Advances in microstructural characterization

“…While much of the early work was strongly oriented towards mechanical engineering, involving the determination of the residual stress distribution and the use of residual stress data in design and life prediction, opportunities for fundamental research began to emerge when it became evident that some of the experimental data could not be understood within the framework of the continuum theory and simple thermal-mechanical simulations [64]. For example, in situ measurements of the grain-orientation-dependent intergranular strains during uniaxial loading have been extensively used to identify the deformation mechanisms in polycrystalline materials [65].…”

Neutron Diffraction

“…Orientations such as <111> and <113> tend to show very small residual strains, comparable with the experimental uncertainty, after unloading to zero macroscopic stress. For example, [33] in bent Incoloy-800 steam generator tubes, the {002} strains exceeded the {111} strains by almost a factor of two near the neutral axis and differed in sign at the top and bottom of the bend. The reference spacing had been taken with respect to straight tube that had not been plastically deformed by bending and displayed no intergranular effects.…”