Abstract
Grain size development during reheating is important to the mechanical properties of steels, and non-uniform grain growth including abnormal and bimodal grain growth is undesirable for steel manufacturing. In this paper, reheating treatments for Al-Nb containing steel (0.057 wt% Al and 0.019 wt% Nb) were selected based on ThermoCalc predictions for the dissolution temperatures of precipitates in the steel for a fully homogenised condition. Abnormal grain growth occurred in the homogenised Al-Nb sample when reheated at 1170 ºC, associated with random dissolution of the grain boundary pinning AlN precipitates; whilst the bimodal grain growth was not observed. Abnormal grain growth was associated with dissolution of the (more stable) AlN precipitates and grain size distributions developed during reheating schedules (1070 – 1200 ºC and 1– 3 hours) have been related to the dissolution rate of AlN.
Original language | English |
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Pages (from-to) | 587-595 |
Journal | Materials Science and Technology |
Volume | 34 |
Issue number | 5 |
Early online date | 10 Dec 2017 |
DOIs | |
Publication status | E-pub ahead of print - 10 Dec 2017 |
Keywords
- abnormal grain growth
- bimodal grain growth
- HSLA steel
- homogenisation
- reheating treatment