Impact of orientation and temperature on strain partitioning in austenite and ferrite phases of additively manufactured super duplex stainless steel

Wire Arc Additive Manufacturing (WAAM) enables fabrication of large-scale, corrosion-resistant components using high-performance alloys such as ER2594 super duplex stainless steel (SDSS). Despite successful WAAM of ER2594, directional thermal gradients during the process introduce strong <001> fibre texture in ferrite. Nevertheless, tensile testing reveals only minor mechanical anisotropy, attributed to the high austenite content (~55%), which exhibits lower texture intensity and likely governs yield onset. However, direct measurements of load sharing between phases during deformation remain absent from open literature.

This study will perform the first in-situ neutron diffraction analysis of phase-specific lattice strains in WAAM-fabricated ER2594 under compressive loading. Using the Engin-X diffractometer, nine cylindrical specimens oriented at 0°, 45°, and 90° to the build direction will be tested at room temperature, 250 °C, and 600 °C to evaluate the influence of orientation and temperature. The lattice strain in ferrite and austenite will be tracked across 18 loading steps.

The experiment will elucidate phase-specific load sharing and its dependence on temperature and orientation, enabling development of validated micromechanical models. Outcomes will inform improved WAAM processing strategies and contribute to qualification of SDSS components for high-performance applications in corrosive and elevated-temperature environments.