<p>To investigate the microstructure evolution and instability during hot deformation, the hot compression experiment was conducted at deformation conditions of 700, 740, 780, 820℃ and strain rates of 0.001, 0.01, 0.1, 1s⁻¹. The modified Johson–Cook constitutive model and 3D hot processing map were established based on experimental data. The finite element simulation was modified based on J–C model and the secondary development based on the 3D instability maps was utilized to investigate the instability region during hot compression experiment. The metrics of <i>R</i> and <i>AARE</i> of constitutive model were 0.9991 and 0.8%, indicating the high prediction accuracy. Comparing to the simulation without modified, the simulation after modified had better prediction accuracy on the stress. The instability regions at different deformation conditions were predicted accurately based on the secondary development. And the result of EBSD further verified the accuracy of the secondary development.</p> Graphical abstract <p></p>