Effects of Residual Stress on Springback in Creep Age Forming of 2219 Aluminum Alloy Double-Curvature Thin-Walled Parts

Residual stresses are inevitably introduced during plate manufacturing and pre-processing (e.g., quenching and pre-stretching). However, springback prediction in creep age forming (CAF) is still frequently carried out by assuming an initially stress-free blank, which may lead to biased deformation–stress histories and tool compensation errors, hindering high-accuracy forming. This study aimed to close this practical gap by quantifying how inherited residual stresses affected the CAF springback of AA2219 double-curvature thin-walled parts. In this study, a multi-step finite element (FE) process chain covering quenching, pre-stretching, and creep age forming (CAF) was developed to investigate the evolution of the initial residual stress field and its influence on CAF springback. Surface residual stresses after quenching and after pre-stretching were measured by X-ray diffraction (XRD) to validate the FE models. The results show that, after quenching, the through-thickness residual stress exhibits a characteristic ‘compressive at the surfaces and tensile in the core’ distribution, and pre-stretching markedly reduces the residual stress level. During CAF, although the initial residual stress difference is largely equilibrated during loading, it affects springback primarily through differences in accumulated creep deformation. Incorporating the initial residual stress field reduces the springback error bandwidth from 9.59 mm to 3.51 mm (a 63.4% reduction) under the original die configuration. Additional simulations under a modified die curvature (geometric deviation ≈ 6 mm) demonstrate that the springback reduction remains at the millimeter scale, indicating that the proposed FE framework maintains a consistent predictive improvement across different curvature conditions. This work provides a theoretical basis and practical guidance for high-precision creep age forming.