Affiliations: Institute Laue-Langevin, 6, rue Horowitz, BP 156, F-38042 Grenoble cedex 9, France | Istituto Nazionale per la Fisica della Materia, Italy, Unit of Grenoble, Grenoble, France | JINR, FLNP, 141980 Dubna, Moscow Region, Russia | Dipartimento di Fisica e Ingegneria dei Materiali e del Territorio, Universita’ di Ancona, via Brecce Bianche, I-60131 Ancona, Italy | CESI, via Rubattino 54, I-20134 Milano, Italy | Istituto di Scienze Fisiche, Universita’ di Ancona, via Ranieri 65, I-60131 Ancona, Italy
Abstract: The Reverse Time of Flight (RTOF) technique, used at the Fourier Diffractometer HRFD of the IBR-2 reactor of the FLNP in Dubna, Russia, is exploited in the neutron diffraction analysis of the residual stress (RS) state in a welded plate of ferritic steel UNI-Fe510D (Italian code). A constant uniaxial stress along the axis transverse to the weld adds to the weld stresses in regions far from the weld pool (WP). Stresses very near to the yield strength have been found. A through-thickness scan shows that stresses are constant as a function of depth. Results are in good agreement with previous work and fulfil the stress balance. The unstrained lattice parameter was found to vary slightly from the parent material to the WP. Good agreement was also obtained with results from the steady state sources of Risø, Denmark (TAS8 diffractometer) and from Řež, near Prague, Czech Republic (TKSN-400 spectrometer). In particular, in spite of the different instrumental concept and measurement method, the through thickness and across weld stress behaviour is common to all the three sets of data.
Keywords: Neutron diffraction, Weld, Reverse time of flight, Ferritic steel, Residual stress
