Residual Stress Evolution in Similar Welds of Carbon Steel, Austenitic Stainless Steel, and Duplex Stainless Steel

This presentation compares residual stress formation in similar welds of AISI 1018 low carbon steel, AISI 304 stainless steel, and duplex stainless steel 2205. The goal is to understand how differences in thermal properties, microstructure, and phase constitution influence the residual stress distribution in welded joints. Residual stresses were measured using neutron diffraction at the HFIR of ORNL on the second-generation neutron residual stress facility (NRSF2). For 1018, the welds show a conventional residual stress profile. A tensile peak develops along the weld centerline in the longitudinal direction, while transverse stresses are lower and normal stresses near the surface remain close to zero. This behavior is consistent with the high thermal conductivity and lower thermal expansion of low-carbon steel. In 304, the stress distribution is different. The longitudinal stresses form an M-shaped profile, with the highest tensile stresses located near the HAZ rather than at the weld centerline. This response is likely related to the lower thermal conductivity, higher thermal expansion coefficient, and plastic relaxation occurring in the austenitic weld metal during cooling. Results for 2205 show more complex behavior because of the coexistence of ferrite and austenite. Phase-specific measurements indicate differences in residual stress between the two phases.