In this paper, in order to improve the microstructure uniformity of an ultra-high strength martensitic steel with a strength greater than 2500 MPa developed by multi-directional forging in the laboratory, a single-pass hot compression experiment with the strain rate of 0.01 to 1 s⁻¹ and a temperature of 800 to 1150 °C was conducted. Based on the experimental data, the material parameters were determined, the constitutive model considering the influence of work hardening, the recrystallization softening on the dislocation density, and the recrystallized grain size model were established. After introducing the model into the finite element software DEFORM-3D, the thermal compression experiment was simulated, and the results were consistent with the experimental results. The rule for obtaining forging stock with a uniform and refinement microstructure was acquired by comparing the simulation and the experimental results, which are helpful to formulate an appropriate forging process.

中文翻译：

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超高强度钢的热变形行为与动态再结晶

本文为了提高实验室多向锻造强度大于2500 MPa的超高强度马氏体钢的组织均匀性，进行了应变速率为0.01~ 1 秒^-1温度为 800 至 1150 ℃。根据实验数据确定材料参数，建立考虑加工硬化、再结晶软化对位错密度影响的本构模型，建立再结晶晶粒尺寸模型。将模型引入有限元软件DEFORM-3D后，进行热压缩实验，结果与实验结果一致。通过对模拟和实验结果的比较，得到了获得组织均匀细化的锻件的规律，有助于制定合适的锻造工艺。