Nucleation kinetics of grain boundary allotriomorphs of proeutectoid ferrite in Fe-C-Mn-X{sub 2} alloys

Journal Article · Wed Mar 01 04:00:00 EST 1995 · Metallurgical Transactions, A

OSTI ID:31962

Tanaka, T; Aaronson, H I ^[1]; Enomoto, M ^[2]

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1. Carnegie Mellon Univ., Pittsburgh, PA (United States)
2. Ibaraki Univ. (Japan). Dept. of Materials Science

The steady-state nucleation rates of ferrite allotriomorphs at the ``faces`` of austenite grain boundaries were measured in Fe-C-X{sub 1}-X{sub 2} alloys, where X{sub 1} was Mn and X{sub 2} was successively Si, Ni, and Co, using techniques previously developed for counterpart studies on Fe-C and Fe-C-X alloys. The results were compared with the predictions of the classical nucleation theory, using the pillbox-shaped critical nucleus model. The volume free energy changes associated with nucleation in Fe-C-X{sub 1}-X{sub 2} quaternary systems were evaluated from the central atoms model (CAM) for both para- and orthoequilibrium modes of transformation. The nucleation process was assumed to be controlled by volume and/or grain boundary diffusion of alloying elements. The so-called synergistic effects of alloying elements were considered in terms of the volume free energy change and interfacial energies on the basis of the result of the nucleation rate measurements.

• OSTI ID: 31962
• Journal Information: Metallurgical Transactions, A, Journal Name: Metallurgical Transactions, A Journal Issue: 3 Vol. 26; ISSN 0360-2133; ISSN MTTABN
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CARBON ADDITIONS
COBALT
COBALT ALLOYS
COMPARATIVE EVALUATIONS
CRYSTAL-PHASE TRANSFORMATIONS
FERRITE
IRON BASE ALLOYS
MANGANESE
MANGANESE ALLOYS
METALLURGICAL EFFECTS
MICROSTRUCTURE
NICKEL
NICKEL ALLOYS
NUCLEATION
QUATERNARY ALLOY SYSTEMS
SILICON
SILICON ALLOYS