Titanium-Dependent Kinetics of Ferrite Single-Phase Recrystallization in Cold-Rolled Ultra-High-Strength Low-Alloy Steels During Annealing

Abstract

The recrystallization behavior of ferrite single phase in ultrahigh-strength low-alloy (UHSLA) steels, with different titanium concentrations (1000, 1500, and 2000 ppm) is presented. Utilizing detailed dilatometer tests, we identified disparities between the observed austenite onset temperatures and those predicted using the JMatPro 13 program and ThermoCalc. This study accentuates the combined effects of titanium, niobium, and reduced manganese levels on the initiation of the ferrite-to-austenite transformation. The Hall–Petch relationship was used to draw a correlation between titanium concentration, yield strength, and grain size. Moreover, we explored the recrystallization kinetics of these steels using the Johnson–Mehl–Avrami–Kolmogorov (JMAK) model, pinpointing titanium's crucial role in modulating the recrystallization dynamics. These findings have significant implications for advancements in steel manufacturing, enhancing the quality and performance of UHSLA steels in industrial applications.