Evolution of texture and residual stresses in 2205 duplex stainless steel during laser powder bed fusion

This study investigates the development of residual stresses in textured 2205 duplex stainless steel during laser powder bed fusion additive manufacturing (LPBF AM). In situ and operando neutron diffraction experiments were conducted to study the transient and real-time evolution of stresses and strains during processing, using an AM machine designed for neutron studies. Additionally, Bragg-edge imaging was employed to investigate the crystallographic texture. The results showed that residual stress redistribution primarily occurs in the first set of added layers when further layers are added on top. The cube texture observed in the sample significantly affects residual stress determination, leading to inaccuracies up to 96 MPa if not accounted for. This highlights the need for orientation-dependent diffraction elastic constants in residual stress calculations. Furthermore, variations in texture intensity across the sample dimensions were found to be driven by changes in the local temperature history, which were deciphered from real-time strain measurements. Finally, this study demonstrates the potential of combining LPBF with neutron diffraction to investigate the underlying mechanisms of AM in the bulk of the sample.