Substitutional alloying effects on reversion kinetics from pearlite structure at 1073 K (800 °C) in an Fe-0.6 mass pct C binary alloy and Fe-0.6C-1 or 2 mass pct M (M = Mn, Si, Cr) ternary alloys were studied. Reverse transformation in the Fe-0.6C binary alloy at 1073 K (800 °C) was finished after holding for approximately 5.5 seconds. The reversion kinetics was accelerated slightly by the addition of Mn but retarded by the addition of Si or Cr. The difference of acceleration effects by the addition of the 1 and 2 mass pct Mn is small, whereas the retardation effect becomes more significant by increasing the amount of addition of Si or Cr. It is clarified from the thermodynamic viewpoint of carbon diffusion that austenite can grow without partitioning of Mn or Si in the Mn- or Si-added alloys. On the one hand, austenite growth is controlled by the carbon diffusion, whereas the addition of them affects carbon activity gradient, resulting in changes in reversion kinetics. On the other hand, thermodynamic calculation implies that the long-range diffusion of Cr is necessary for austenite growth in the Cr-added alloys. It is proposed that austenite growth from pearlite in the Cr-added alloys is controlled by the diffusion of Cr along austenite/pearlite interface.
|Number of pages||11|
|Journal||Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science|
|Publication status||Published - 2011 Jun 1|
ASJC Scopus subject areas
- Condensed Matter Physics
- Mechanics of Materials
- Metals and Alloys