Abstract
Manufacturing processes can generate high residual stress fields that affect the fatigue resistance of components, especially at discontinuities in those that are thick with complex shapes and where radii are small. Welds present residual stress and distortion problems and tremendous challenges for lifetime predictions in aerospace, aero-engine and power generating industries. They represent perhaps 50% of the problem studies by neutron diffraction but are some of the most difficult to interpret because the composition and structure can vary across the weld and heat-affected zone. The HB4 and HB5 neutron diffraction facilities at the High Flux Reactor (HFR) in Petten have been used for the investigation of residual stresses in two structural component cases. The first concerns an austenitic steel piping weld specimen while the second deals with two low alloy steel cast truck motor part specimens. The overall objective in the second case was the evaluation of the post-production heat treatment process to which one of the two identical specimens was subjected.