Residual Stress Analyses Based on Neutron Diffraction in Double-V Butt Welded Steel Plates *

Abstract

Residual stress measurements on a double-V butt weld joining two plates of nominally identical stainless steel have been performed using two neutron diffractometers. Sections of 270, 30 and 4 mm length cut from an original welded plate of 2.5 m length and 400 mm width were investigated using the large component neutron diffraction facility (LCNDF), at beam tube HB4, and the recently recommissioned combined powder and stress diffractometer, at beam tube HB5, at the high flux reactor (HFR) of the European Commission in Petten. Strains and stresses have been mapped in specimens of all three sizes testing the weld longitudinal, welding transverse and plate normal directions. The test results show a significant stress relaxation due to specimen cutting only in the direction normal to the cuts, e.g. from 270 to 30 mm length reduced the weld longitudinal stresses by 50%. In the other two in-plane directions the stresses were found largely unaltered.