Microstructural Evolution and Springback Mechanism of 304/201/304 Stainless Steel Composite Plate in Single‐Pass Roll Bending

Springback in metal composite plates is more complex than that of single metals because of interlayer property differences and interface effects. This study investigates single‐pass V‐shaped roll bending of 304/201/304 stainless steel composite plates at forming angles of 15°, 25°, and 45° through finite element simulation and experiments. Electron backscatter diffraction (EBSD) characterizes microstructural evolution to clarify the springback mechanism, while X‐ray diffraction (XRD) and vibrating sample magnetometry (VSM) identify the phase transformation mechanism. Results show that dislocation slip governs plastic deformation, and no significant martensitic transformation occurs. As the forming angle increases, average grain size, 60°/ twin boundaries, and average grain boundary misorientation decrease, whereas low‐angle grain boundaries (LAGBs) increase, indicating intensified deformation. At the same angle, the outside exhibits higher geometrically necessary dislocation (GND) density, greater microhardness, and a larger increase in transverse plastic strain than the inside, confirming more severe deformation and hardening. This imbalance restricts the elastic recovery of the inside during unloading, causing it to experience a reaction force from the outside and undergo slight additional deformation. Consequently, the springback shifts from a positive 0.08° at 15° to negative values of −0.33° at 25° and −1.00° at 45°, becoming increasingly pronounced with larger forming angles.