奥氏体不锈钢屈服强度普遍较低，显著制约了其作为结构材料的应用。本工作旨在通过形变退火工艺开发具有超高屈服强度的超细晶奥氏体不锈钢，并系统揭示退火温度对显微组织演变、富Cu粒子析出行为及力学性能的调控规律。采用201LN奥氏体不锈钢作为原始材料，经60%冷轧变形后，分别在600和700 ℃条件下进行退火处理。采用OM、TEM、EBSD技术和万能试验机对试样的微观组织和力学性能进行了系统表征。结果表明，经700 ℃退火1 min和600 ℃退火600 min，均可获得平均晶粒尺寸约为0.8 μm的超细晶奥氏体不锈钢。此外，在600 ℃退火样品中观察到高度有序排列的纳米级富Cu粒子。力学性能测试结果表明，700 ℃退火1 min样品的屈服强度为786 MPa，伸长率为40%；而600 ℃退火600 min样品由于结合了细晶强化与高密度共格富Cu粒子析出强化，其屈服强度显著提升至1300 MPa，同时仍保持了25%的伸长率，其中析出强化对屈服强度的贡献约为342 MPa。由于细晶强化与析出强化协同作用，在实现奥氏体不锈钢强度显著提升的同时有效保持了其良好的塑性。

The relatively low yield strength of austenitic stainless steels limits their structural applications. Therefore, this study aims to fabricate ultrafine-grained austenitic stainless steels with ultrahigh yield strength through deformation annealing and systematically investigate how annealing temperatures regulate microstructural evolution, Cu-rich particle precipitation, and mechanical properties. Using 201LN austenitic stainless steel as the starting material, we performed 60% cold rolling followed by annealing treatments at 600°C and 700°C. Comprehensive microstructural characterization was conducted using OM, TEM, and EBSD, and mechanical properties were evaluated through universal testing. Annealing at 700°C for 1 min and at 600°C for 600 min resulted in ultrafine-grained austenitic stainless steels with an average grain size of approximately 0.8 μm. Notably, highly ordered nanoscale Cu-rich particles were observed for the first time in the sample annealed at 600°C. Mechanical property tests showed that the sample annealed at 700°C for 1 min achieved a yield strength of 786 MPa with 40% elongation. In contrast, the sample annealed at 600°C for 600 min exhibited a considerably higher yield strength of up to 1300 MPa while maintaining 25% elongation. This enhanced strength is attributed to the combined effects of grain refinement and precipitation strengthening induced by high-density coherent Cu-rich particles, with precipitation strengthening contributing approximately 342 MPa to the yield strength. The synergistic effect of grain refinement and precipitation strengthening effectively improves the strength of austenitic stainless steel while retaining favorable ductility.