A study of austenite grain growth in a Ti-Nb HSLA steel

• Main Author: Lechuk, Steven John
• Format: Others
• Language: English
• Published: 2009
• Online Access: http://hdl.handle.net/2429/11317

Austenite grain growth kinetics have been studied in a Ti-Nb microalloyed low carbon steel in the temperature range of 1100 to 1250°C, employing a Gleeble® 1500 thermomechanical simulator. No significant grain growth has been observed below 1100°C. The onset of grain growth at 1150°C, both normal and abnormal, is related to the coarsening and dissolution of precipitates. This is confirmed and quantified by transmission electron microscopy analyses. For this purpose, the statistical grain growth model of Abbruzzese and Liicke is combined with the model by Cheng et al. for the coarsening and dissolution of precipitates. An austenite grain growth model has been developed which correlates the time and temperature dependence of the pinning force to the dissolution kinetics of the Ti-Nb carbonitrides in the steel. The model predictions are consistent with the experimental observations of grain size and particle size evolution. === Applied Science, Faculty of === Materials Engineering, Department of === Graduate