This article explores the characteristic flow behaviour and microstructure analysis of Si–Cr spring steel under various compression conditions by a Gleeble 3500 facility. To better simulate the abrupt and complex compression during the hot forming process, three compression strain rates (0.01 s⁻¹, 0.1 s⁻¹, and 1 s⁻¹) and four compressive temperatures (850, 900, 950 and 1000 °C) were selected. The outcomes exhibit the intragranular dislocation cells and pile-up along the subgrains were formed during the dynamic recovery (DRV) progress. The dynamic recrystallisation (DRX) of the experimental steel arose with a higher value of the compression temperature. On this basis, a strain-compensated constitutive model considering the compression activation energy and a linear correlation between the Z parameter and DRX grain size are both established according to the strain-stress curves. The constitutive model is further verified by the multiple sets of hot deformation data and exhibits a good agreement between experimental and predicted points with an excellent correlation coefficient of 0.986 and a low relative error of 5.41%, indicating the reliability of the constitutive model throughout the entirety of the hot deformation process.

本文探讨了通过Gleeble 3500设备在各种压缩条件下Si-Cr弹簧钢的特征流动行为和显微组织分析。为了更好地模拟热成型过程中的突然和复杂压缩，三个压缩应变率（0.01 s ^-1、0.1 s ^-1和1 s ^-1）和四个压缩温度（850、900、950和1000°C）。结果表明，在动态恢复（DRV）过程中，颗粒内位错细胞和沿亚晶粒的堆积形成了。实验钢的动态重结晶（DRX）以较高的压缩温度值出现。在此基础上，根据应变应力曲线建立了考虑压缩激活能以及Z参数与DRX晶粒尺寸之间线性相关关系的应变补偿本构模型。本构模型由多组热变形数据进一步验证，并且在实验点和预测点之间显示出良好的一致性，相关系数为0.986，相对误差为5.41％，