Constitutive Modeling and Hot Workability Considering Friction‐Temperature Correction for the Spray‐Formed V2 High‐Speed Steel

The mechanical properties of high‐speed steel are enhanced through grain refinement and macrosegregation suppression via the precision spray forming (PSF) process. However, during the hot working process, such as forging or extrusion, PSF V2 high‐speed steel is prone to forming defects including cracks and coarse grains. It is essential to elucidate the hot deformation behavior and microstructure evolution for the PSF V2 high‐speed steel to achieve the optimization of hot workability. Thermal compression experiments were conducted using the Gleeble‐1500D testing machine at a temperature range of 900°C–1100°C and strain rate from 0.01 to 10 s −1 . An Arrhenius constitutive model was established and validated. The hot processing window integrating macroscopic and microscopic mechanisms was established coupled with the activation energy, power dissipation factor, and flow instability criteria. Under different strains, the linear correlation coefficient and the average relative error between the predicted values and experimental results are 0.983% and 7.341%, respectively, which indicates high reliability and predictive accuracy of the model. The optimal hot working window for PSF V2 high‐speed steel was determined by combining theoretical criteria and microstructure characteristics: the deformation temperature range of 1003°C–1086°C and the strain rate of 0.04–0.58 s −1 .