Effect of Solid-Solution Second-Phase Particles on the Austenite Grain Growth Behavior in Nb-Ti High-Strength if Steel
© 2020, Springer Science+Business Media, LLC, part of Springer Nature. The effect of the solid solution of second-phase particles on the austenite grain growth behavior at different heating temperatures and holding times of Nb-Ti high-strength IF steel is examined. The experimental results showed that the solid solubility of Nb in austenite increased significantly with temperature, dispersion and fine second-phase particles continued to dissolve in austenite. The pinning effect weakened and the austenite grains increased slowly. When temperature reached 1050 °C, a large number of second-phase particles (NbC, TiC, etc.) gradually dissolved in austenite. The solid solubility of microalloyed elements in austenite used for testing steel was different. To make these elements dissolved completely and, at the same time, obtain fine-grained austenite, heating temperature needs to be kept between 1050–1100°C and the holding time limited to 30–40 min. The austenite grain growth model is constructed based on the experimental data. The calculated values are in agreement with the experimental results.