| Abstract Scope |
Precipitation-strengthened Fe-Mn-Al-C steels are promising for high-strength, lightweight structural plate applications, but weld thermal cycles disrupt the austenitic matrix and nanoscale precipitate populations responsible for strengthening. Recent work established a thermomechanical processing route for Fe-17.7Mn-4.7Cr-0.48C-10Ni-5Al-4Cu, which is strengthened by B2-NiAl and Cu-rich precipitates. Weld response is evaluated in processed Fe-Mn-Al-C-Ni-Cu-Cr using autogenous TIG weld-pass screening. Targeted compositional changes are used to compare susceptibility to solidification cracking, ferrite formation, precipitate dissolution or coarsening, elemental segregation, and local hardness gradients across the fusion zone, heat-affected zone, and base metal. Weld cross sections are evaluated to relate composition to solidification structure, matrix stability, precipitate retention, grain growth, phase formation, and mechanical response. Composition-processing combinations are identified that limit weld-induced ferrite formation, precipitate instability, and hardness gradients in Fe-Mn-Al-C steels. |