针对Mn-N系节约型TRIP双相不锈钢在结构碰撞等高应变率压缩条件下绝热温升显著、相变行为易被抑制以及动态本构描述不足的问题，本工作采用准静态压缩与分离式Hopkinson压杆(SHPB)实验，系统研究了具有相变诱导塑性(TRIP)效应的Mn-N系节约型双相不锈钢在宽应变率范围(2.0 × 10^-3~4.0 × 10³ s^-1)内的力学响应及微观变形机制。结果表明，双相不锈钢兼具高强度与良好塑性，在动态冲击压缩下未产生剪切断裂，表现出显著的应变率敏感性，其屈服强度与抗压强度均随应变率提高而增加；在应变率为4.0 × 10³ s^-1时，轧制方向(RD)的屈服强度与抗压强度分别高达800和1143 MPa。微观机理分析表明，双相不锈钢的塑性变形机制受应变率影响：在准静态条件下，发生显著的马氏体相变，其相变路径为γ→ε→α¢和γ→α¢。然而高应变率(4.0 × 10³ s^-1)条件下的绝热温升效应增强了奥氏体稳定性，TRIP效应被抑制，相变路径以γ→α¢为主，α¢马氏体的体积分数大幅降低；此时，塑性变形由铁素体相内位错墙的形成以及奥氏体相内位错滑移与形变孪晶的协同作用所主导。根据上述机理，建立了考虑绝热温升效应的修正Johnson-Cook本构模型，可准确描述双相不锈钢的动态响应。

Mn-N-alloyed transformation-induced plasticity (TRIP)-assisted duplex stainless steel is a promising Ni-saving advanced high-strength steel for impact-resistant structural applications due to its high strength, good plasticity, and the TRIP effect. However, under high-strain-rate compression, adiabatic temperature rise can enhance austenite stability, suppress martensitic transformation, and render conventional dynamic constitutive descriptions insufficient. This work investigates a Mn-N-alloyed TRIP-assisted duplex stainless steel through quasi-static compression and split Hopkinson pressure bar tests across a wide strain-rate range, from 2.0 × 10⁻³ s⁻¹ to 4.0 × 10³ s⁻¹. Specimens were compressed along the rolling direction. The strain-rate-dependent mechanical response was analyzed alongside the evolution of martensite fraction, phase transformation behavior, local misorientation, crystallographic texture, and deformation substructures. SEM, EBSD, TEM, magnetic measurements, and thermodynamic calculations of the stacking fault energy were combined to reveal the underlying deformation mechanisms. Based on these findings, a modified Johnson–Cook constitutive model incorporating adiabatic heating was established to describe the steel’s dynamic flow behavior. Results show that the duplex stainless steel exhibits an excellent combination of high strength and plasticity, with no shear fracture observed during high-strain-rate impact compression. Both dynamic yield strength and compressive strength increase with increasing strain rate. At a strain rate of 4.0 × 10³ s⁻¹, the yield strength and compressive strength along the rolling direction reach 800 and 1143 MPa, respectively. The deformation mechanism changes substantially with strain rate. Under quasi-static compression, significant martensitic transformation occurs via both γ→ε→α¢ and γ→α¢ transformation paths, and the volume fraction of α′ martensite reaches 8.66%. By contrast, at 4.0 × 10³ s⁻¹, adiabatic heating enhances austenite stability and suppresses the TRIP effect, reducing the α′ martensite fraction to 0.92%. The transformation path is then dominated by the direct γ→α¢ transformation, whereas the γ→ε→α¢ route is strongly inhibited. Thermodynamic calculations show that the stacking fault energy increases from 20.92 mJ/m² at room temperature to 41.08 mJ/m² under the highest-strain-rate condition. This shifts the deformation mode from TRIP-dominated deformation toward a synergistic mechanism involving deformation twinning, the residual TRIP effect, and dislocation slip. TEM observations further confirm that plastic deformation at high strain rates is primarily facilitated by the formation of dislocation walls in ferrite, along with dislocation slip, stacking faults, and deformation twins in austenite. The modified Johnson–Cook model, which introduces adiabatic temperature rise into the thermal softening term, accurately reproduces the nonlinear dynamic flow stress response while avoiding the overestimation associated with the conventional isothermal Johnson–Cook model. These findings provide a mechanistic basis and a constitutive description for the application of TRIP-assisted duplex stainless steels in impact-resistant structural design.