Comparison of Grain Growth between Fine-Grained and Coarse-Grained Austenite in a Nb-V-Ti Microalloyed Steel

Abstract:

Comparison of grain growth of fine-grained and coarse-grained austenite in a Nb-V-Ti microalloyed steel during reheating or equalization at the same temperature was investigated using cold-charging and hot-charging specimens respectively in this study. The results show that the different grain growth behavior appears in fine-grained and coarse-grained austenite. The uniform grain growth and lower growth rate at reheating temperature studied was found in fine-grained austenite, while partial grain growth and higher growth rate was present in coarse-grained austenite. During reheating or equalization, the slow growth rate in fine-grained austenite may be contributed to stronger pinning force of fine precipitates while higher grain growth rate in coarse-grained austenite were believed to the result of lager size difference among part of grains. Grain coarsening occurs in fine-grained austenite as result of precipitate unpinning at extending holding time, but coarse-grained austenite remained wide size distribution at the same condition and this should not be considered as grain coarsening. coarse-grained austenite remained wide size distribution at the

• Periodical: Materials Science Forum (Volumes 638-642)
• Pages: 3496-3501
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.638-642.3496
• Online since: January 2010
• Authors: Qing Yun Sha, Li Feng Qiao, Rong Jie Xu, Guo Jian Huang, Zu Qing Sun
• Keywords: Austenite Grain Size, Cold Charging, Grain Growth Rate, Hot Charging

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