A precise flow curve for a wide range of forming conditions is important for accurately predicting forming force. Moreover, since the flow curve reflects microstructural changes, its accurate description must be obtained under various temperatures and strain rates up to 300 s⁻¹. For practical forming processes such as hot strip rolling and wire rod rolling, the deformation behavior at high strain rates (50–200 s⁻¹) must also be studied. However, a uniform axial high strain rate is difficult to achieve. Hence, a new deceleration method is developed. Also, the compression test at high strain rates is accompanied by marked internal heat generation, Therefore, temperature and deformation are highly inhomogeneous compared with those in tests at lower strain rates. In addition to this problem, heat conduction to the die and friction should be corrected using inverse analysis. By considering the internal temperature increase effect at high strain rates, the uniaxial flow curve obtained using inverse analysis is shown to be greater than the experimental apparent stress–axial strain curve. And then, a regression method is applied to obtain a generalized flow curve at high strain rates, which can cover wider ranges of strain rates and temperatures. Finally, they are compared with an extrapolated flow curve that is regressed using an intermediate strain rate in our previous research. By comparing those results, the extrapolated flow curve is greatly different from the flow curve obtained in the current research. To find the reason for the difference, a microstructure analysis using EBSD is implemented.

对于广泛的成形条件而言，精确的流动曲线对于准确预测成形力很重要。此外，由于流动曲线反映了微观结构的变化，因此必须在高达300 s ^-1的各种温度和应变速率下获得准确的描述。对于诸如热轧带钢和线材轧制等实际成形过程，在高应变率（50–200 s ^-1时）下的变形行为）也必须进行研究。然而，难以实现均匀的轴向高应变率。因此，开发了一种新的减速方法。另外，在高应变率下的压缩试验伴随着明显的内部发热，因此，与在较低应变率下的试验相比，温度和变形高度不均匀。除此问题外，还应使用反分析来校正对模具的导热和摩擦。通过考虑在高应变速率下内部温度升高的影响，使用逆分析获得的单轴流动曲线显示大于实验的表观应力-轴向应变曲线。然后，使用回归方法获得高应变率下的广义流动曲线，该曲线可以覆盖更宽的应变率和温度范围。最后，在我们先前的研究中，将它们与使用中间应变率回归的外推流量曲线进行比较。通过比较这些结果，外推流量曲线与当前研究中获得的流量曲线有很大不同。为了找到差异的原因，使用EBSD进行了微结构分析。