Effect of Cr on the Dynamic Recrystallization Behavior of Austenite and Ti(C,N) Precipitation in Ti‐Microalloyed Steel During High‐Temperature Deformation

The dynamic recrystallization (DRX) behavior of austenite in Ti‐microalloyed steel is influenced by hot‐deformation parameters, deformation stored energy, solute drag, and second‐phase pinning. Single‐pass hot‐compression tests investigated DRX in Cr‐free and Cr‐bearing Ti‐microalloyed steels, focusing on Cr effects on stored energy, solute drag, Ti(C,N) precipitation, and austenite grain size. Results show Cr suppresses DRX, increasing apparent activation energy and DRX temperature by ~10 kJ/mol and 50 °C, respectively. While Cr slightly increases deformation‐stored energy, this effect is limited. Precipitate characterization and thermodynamic calculations reveal Cr suppresses precipitation by decreasing molar driving force through entering Ti(C,N) and increasing its solubility product in austenite; the latter dominates, shifting the PTT curve rightward. The effect of Cr on grain size depends on temperature and strain rate. At 1100 °C (0.01–10 s −1 ) and 1050–1000 °C (1–10 s −1 ), no strain‐induced precipitation occurs, and weak solute drag refines grains. At 1050–1000 °C (0.01–0.1 s −1 ), strain‐induced Ti(C,N) precipitation occurs, which is suppressed by Cr, resulting in weakened pinning and grain coarsening. Cr affects DRX through weak solute drag and suppressed Ti(C,N) precipitation, with the dominant mechanism varying with deformation conditions, providing theoretical guidance for TMCP optimization of Cr‐bearing Ti‐microalloyed steels.