Neutron diffraction measurement of residual stress in high strength, highly restrained, thick section steel welds

Abstract

In order to determine the influence of a flaw on the integrity of a welded structure the magnitude of the stress, including residual stress, acting on the flaw must be quantified. Variations in residual stress in thick steel sections are difficult to determine as most residual stress analysis methods allow only for surface residual stress to be measured. This paper describes the use of neutron strain scanning to provide through thickness three-dimensional strain scans of both an unwelded and butt welded steel sample. Additional techniques have been used to monitor changing surface stresses during sample preparation and these results are compared and used in conjunction with the strain scanning results. All neutron scans were performed on the Australian Strain Scanner, Lucas Heights.