Austenite particle coarsening and delta-ferrite grain growth in model Fe-Al alloy

作者：Zhou T H; Gheribi A E; Zurob H S^*

来源：Canadian Metallurgical Quarterly, 2013, 52(1): 90-97.

DOI：10.1179/1879139512Y.0000000037

• Grain growth
• Austenite particles coarsening
• Austenite particles pinning
• Limiting grain size

The grain growth kinetics of delta-ferrite was investigated in a model Fe-Al alloy in which a small volume fraction of austenite particles is used to control grain growth. The specimens were heated to different temperatures in the two phase (delta-ferrite+austenite) region and held for times between 5 min and 288 h followed by water quenching. The coarsening kinetics of the austenite particles could be described both in terms of bulk (t(1/3)) and grain boundary (t(1/4)) diffusion. The growth of the delta-ferrite grains was dominated by the pinning effect of the austenite particles. When the particle pinning pressure was much larger than the driving force for grain growth, the growth of delta-ferrite grains was completely pinned. Under conditions in which the particle pinning force and the driving force for grain growth were comparable, ferrite grain growth occurred at a rate which is proportional to the rate of coarsening of the austenite particles. When the particle pinning force is smaller than the driving force, grain growth occurs at a rate which is lower than that expected without pinning.

• 出版日期2013-1