Papers by Keyword: Intergranular Strain

Abstract: Complex strain paths are often applied to materials during production processes. This paper shows the first successful in-situ biaxial mechanical tests during neutron diffraction performed on a cruciform steel sample and reports on the differences compared to uniaxial deformation. Digital image correlation is demonstrated to be an appropriate tool to monitor spatially resolved the macroscopic straining. The new, modular biaxial machine that will be installed at the neutron diffractometer POLDI is presented.

Abstract: Material of the specimen was austenitic stainless steel (SUS316L). The specimens were given tensile plastic strains from 0% to 55%. The Vickers hardness of the specimen corresponded to the plastic strain. The residual macrostress was measured by Mn-Kα radiations. The residual macrostress of the annealed specimen had a small compression and changed into a tension after ten- sile plastic deformation. The specimen with 1% plastic strain showed the maximum tensile residual stress. To examine the dependency of the residual stress on the lattice plane, the residual microstress for each lattice plane was measured by hard synchrotron X-rays. The residual microstress was related with Young’s modulus which was calculated by Kro¨ ner model. A new method, 2θ-cos2 χ method, was proposed to solve the problem of coarse grains and it was excellent in comparison with the sin2 ψ method.

Abstract: Complementary methods have been used to analyse residual stresses in zirconium alloy tubes which were manufactured by cold rolling : X-ray diffraction and scale transition model. A modified elasto-plastic self-consistent model (EPSC) has been used to simulate the experiments and exhibits agreement with experimental data. X-ray diffraction analysis in rolling direction shows opposite stress values for {10 14 } and { 2022} planes respectively. The measured strains were generated by an anisotropic plastic deformation. Plastic incompatibility stress on X-ray measurements should be taken into account so as to make a correct interpretation of the experimental data.