Electro-Recrystallization-Driven Microstructure, Twin Boundary Network, and Texture Evolution in Cold-Rolled Ni-20Cr Alloys Under Low-Temperature Electro-Treatment

Abstract The effects of direct-current electro-treatment on the microstructure and properties of cold-rolled Ni-20 wt.% Cr alloy were systematically investigated using electron backscatter diffraction (EBSD), a micro-Vickers hardness tester, and a four-point probe. Controlled current densities (1.2–1.8 × 10 4 A/cm 2 ) were applied to clarify the thresholds for electro-recrystallization and twin boundary evolution. Electro-recrystallization initiated at 1.2 × 10 4 A/cm 2 and completed at 1.4 × 10 4 A/cm 2 , accompanied by extensive formation of Σ3 annealing twin boundaries and texture transition from deformation to recrystallization components. At 1.8 × 10 4 A/cm 2 for 1 h, apparent grain growth occurred, with significant reductions in microhardness (− 56.8%) and electrical resistivity (− 33.1%) observed. In contrast, an isothermal thermal benchmark at the same treatment temperature produced negligible changes, confirming the dominant athermal electron-defect interaction as the primary driver of recrystallization. These findings demonstrate that direct-current electro-treatment enables low-temperature, energy-efficient recrystallization and twin-assisted grain boundary engineering, establishing Ni-20 wt.% Cr as a model system for current-assisted microstructure control in Inconel alloys.