This paper presents an experimental investigation on the dynamic mechanical performance of S30408 austenitic stainless steel (ASS) under elevated temperatures, which is essential for determining the behaviour of structures made with this type of steel subjected to the coupled fire and impact/explosion. For this purpose, the quasi-static and dynamic compression tests using Split Hopkinson Pressure Bar (SHPB) were conducted under temperatures of 20–600 °C and strain rates from 0.001 to 3000 s⁻¹. In addition, the corresponding microstructures of tested samples were observed. The stress–strain responses, strain rate and temperature effects as well as the microstructural evolutions were analyzed. Test results show that the stress–strain responses are sensitive to the strain rate and temperature. The strain-rate sensitivity coefficient increases as the strain rate and temperature rise. The microstructural observation reveals that the grain dimension declines with an increment of strain rate or a decreasing temperature. Finally, the dynamic compressive stress–strain models for S30408 ASS under 20–600 °C were suggested on the basis of the Johnson-Cook (J-C) model and have been proved to give a reasonable prediction.

本文对 S30408 奥氏体不锈钢 (ASS) 在高温下的动态机械性能进行了实验研究，这对于确定由此类钢制成的结构在遭受火灾和冲击/爆炸耦合时的行为至关重要。为此，在 20–600 °C 的温度和 0.001 到 3000 s ^{-1 的}应变率下进行了使用 Split Hopkinson Pressure Bar (SHPB) 的准静态和动态压缩测试. 此外，还观察了测试样品的相应微观结构。分析了应力-应变响应、应变速率和温度效应以及微观结构演变。测试结果表明应力-应变响应对应变速率和温度敏感。应变率敏感系数随着应变率和温度的升高而增加。显微组织观察表明，晶粒尺寸随着应变速率的增加或温度的降低而下降。最后，在 Johnson-Cook (JC) 模型的基础上提出了 S30408 ASS 在 20-600 °C 下的动态压应力-应变模型，并被证明给出了合理的预测。