Residual Stress Measurements in Structural Components by Neutron Diffraction

摘要

Manufacturing processes can generate high residualstress fields that affect the fatigue resistance of components,especially at discontinuities in those that are thick with complexshapes and where radii are small. Welds present residual stress anddistortion problems and tremendous challenges for lifetimepredictions in aerospace, aero-engine and power generatingindustries. They represent perhaps 50 precent of the problemstudies by neutron diffraction but are some of the most difficult tointerpret because the composition and structure can vary across theweld and heat-affected zone. The HB4 and HB5 neutrondiffraction facilities at the High Flux Reactor (HFR) in Pettenhave been used for the investigation of residual stresses in twostructural component cases. The first concerns an austenitic steelpiping weld specimen while the second deals with two low alloysteel cast truck motor part specimens. The overall objective in thesecond case was the evaluation of the post-production heattreatment process to which one of the two identical specimens was subjected.