TRIP型双相不锈钢因其显著降低的密度以及TRIP效应带来的优异延展性和加工硬化能力，逐渐被广泛应用于新能源汽车行业。然而，钢中奥氏体稳定性的差异会影响TRIP效应，从而改变材料的循环塑性行为。本工作以两种奥氏体稳定性不同的双相不锈钢为研究对象，通过对比分析两种材料在循环加载下的力学响应特征与微观组织演变，探究奥氏体稳定性对TRIP型双相不锈钢循环塑性行为的影响，并阐明其微观机理。结果表明，随着奥氏体稳定性的降低，α'马氏体相变程度增大，且除在ε马氏体带交点处形核外，还出现了直接在ε马氏体带上形核的现象。奥氏体稳定性的降低会使材料循环软化效果减弱，二次硬化能力增强；此外，还提高了α'马氏体的相变速率和相变量，加重各相间的性能不协调与应变不连续程度，从而易于在各相界面和α'马氏体相变处萌生微裂纹，降低材料的疲劳寿命。

TRIP-assisted duplex stainless steels (DSSs) have gradually gained widespread application in the new energy vehicle industry due to its significantly reduced density and the excellent ductility and work hardening capability induced by the TRIP effect. However, the differences in the stability of austenite in the steel can affect the TRIP effect, thereby altering the material's cyclic plasticity behavior. This study investigates two DSSs with different austenite stabilities. By comparing and analyzing the mechanical responses and microstructural evolution of these materials under cyclic loading, the influence of austenite stability on the cyclic plasticity behavior of TRIP-assisted DSSs is explored, along with the underlying microstructural mechanisms. The results indicate that with a decrease in austenite stability, the degree of α' martensitic transformation increases. In addition to nucleation at the intersections of the ε-martensite bands, nucleation is also observed directly on the ε-martensite bands. The reduction in austenite stability weakens the cyclic softening effect of the material, enhances its secondary hardening capacity, and increases the transformation rate and volume fraction of α' martensite. This leads to a higher degree of performance mismatch and strain discontinuity between the phases, making it easier for microcracks to initiate at phase interfaces and at the α' martensite transformation sites, thus reducing the material's fatigue life.