Formation mechanism of bainitic ferrite in an Fe-2 Pct Si-0.6 Pct C alloy

Kaneaki Tsuzaki, Aki Kodai, Tactashi Maki

Research output: Contribution to journalArticle

37 Citations (Scopus)

Abstract

The bainite transformation at 723 K in an Fe-2 pct Si-0.6 pct C alloy (mass pct) was investigated with transmission electron microscopy (TEM) and quantitative metallography to clarify the growth mechanism of the ferritic component of bainite. In early stages of transformation, the bainitic ferrite was carbide free. The laths of bainitic ferrite within a packet were parallel to one another and separated by carbon-enriched retained austenite. The average carbon concentration of the bainitic ferrite was estimated to be 0.19 mass pct at the lowest, indicating that the ferrite was highly supersaturated with respect to carbon. The laths did not thicken during the subsequent isothermal holding, although they were in contact with austenite of which the average carbon concentration was lower than the paraequilibrium value. In the later stage of transformation, large carbide plates formed in the austenite between the laths, resulting in the decrease in the carbon concentration of the austenite. Subsequently, the ferrite with a variant different from the initially formed ferrite in the packet was decomposed for the completion of transformation. The present results indicate that the bainitic ferrite develops by a displacive mechanism rather than a diffusional mechanism.

Original languageEnglish
Pages (from-to)2009-2016
Number of pages8
JournalMetallurgical and Materials Transactions A
Volume25
Issue number9
DOIs
Publication statusPublished - Sep 1 1994
Externally publishedYes

Fingerprint

Ferrite
ferrites
austenite
Carbon
Austenite
carbon
bainite
Bainite
carbides
Carbides
metallography
Metallography
low concentrations
Transmission electron microscopy
transmission electron microscopy

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics
  • Mechanics of Materials
  • Metals and Alloys

Cite this

Formation mechanism of bainitic ferrite in an Fe-2 Pct Si-0.6 Pct C alloy. / Tsuzaki, Kaneaki; Kodai, Aki; Maki, Tactashi.

In: Metallurgical and Materials Transactions A, Vol. 25, No. 9, 01.09.1994, p. 2009-2016.

Research output: Contribution to journalArticle

@article{4fe5ea6b0ad54f4a9fc769c3da9d9977,
title = "Formation mechanism of bainitic ferrite in an Fe-2 Pct Si-0.6 Pct C alloy",
abstract = "The bainite transformation at 723 K in an Fe-2 pct Si-0.6 pct C alloy (mass pct) was investigated with transmission electron microscopy (TEM) and quantitative metallography to clarify the growth mechanism of the ferritic component of bainite. In early stages of transformation, the bainitic ferrite was carbide free. The laths of bainitic ferrite within a packet were parallel to one another and separated by carbon-enriched retained austenite. The average carbon concentration of the bainitic ferrite was estimated to be 0.19 mass pct at the lowest, indicating that the ferrite was highly supersaturated with respect to carbon. The laths did not thicken during the subsequent isothermal holding, although they were in contact with austenite of which the average carbon concentration was lower than the paraequilibrium value. In the later stage of transformation, large carbide plates formed in the austenite between the laths, resulting in the decrease in the carbon concentration of the austenite. Subsequently, the ferrite with a variant different from the initially formed ferrite in the packet was decomposed for the completion of transformation. The present results indicate that the bainitic ferrite develops by a displacive mechanism rather than a diffusional mechanism.",
author = "Kaneaki Tsuzaki and Aki Kodai and Tactashi Maki",
year = "1994",
month = "9",
day = "1",
doi = "10.1007/BF02649049",
language = "English",
volume = "25",
pages = "2009--2016",
journal = "Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science",
issn = "1073-5623",
publisher = "Springer Boston",
number = "9",

}

TY - JOUR

T1 - Formation mechanism of bainitic ferrite in an Fe-2 Pct Si-0.6 Pct C alloy

AU - Tsuzaki, Kaneaki

AU - Kodai, Aki

AU - Maki, Tactashi

PY - 1994/9/1

Y1 - 1994/9/1

N2 - The bainite transformation at 723 K in an Fe-2 pct Si-0.6 pct C alloy (mass pct) was investigated with transmission electron microscopy (TEM) and quantitative metallography to clarify the growth mechanism of the ferritic component of bainite. In early stages of transformation, the bainitic ferrite was carbide free. The laths of bainitic ferrite within a packet were parallel to one another and separated by carbon-enriched retained austenite. The average carbon concentration of the bainitic ferrite was estimated to be 0.19 mass pct at the lowest, indicating that the ferrite was highly supersaturated with respect to carbon. The laths did not thicken during the subsequent isothermal holding, although they were in contact with austenite of which the average carbon concentration was lower than the paraequilibrium value. In the later stage of transformation, large carbide plates formed in the austenite between the laths, resulting in the decrease in the carbon concentration of the austenite. Subsequently, the ferrite with a variant different from the initially formed ferrite in the packet was decomposed for the completion of transformation. The present results indicate that the bainitic ferrite develops by a displacive mechanism rather than a diffusional mechanism.

AB - The bainite transformation at 723 K in an Fe-2 pct Si-0.6 pct C alloy (mass pct) was investigated with transmission electron microscopy (TEM) and quantitative metallography to clarify the growth mechanism of the ferritic component of bainite. In early stages of transformation, the bainitic ferrite was carbide free. The laths of bainitic ferrite within a packet were parallel to one another and separated by carbon-enriched retained austenite. The average carbon concentration of the bainitic ferrite was estimated to be 0.19 mass pct at the lowest, indicating that the ferrite was highly supersaturated with respect to carbon. The laths did not thicken during the subsequent isothermal holding, although they were in contact with austenite of which the average carbon concentration was lower than the paraequilibrium value. In the later stage of transformation, large carbide plates formed in the austenite between the laths, resulting in the decrease in the carbon concentration of the austenite. Subsequently, the ferrite with a variant different from the initially formed ferrite in the packet was decomposed for the completion of transformation. The present results indicate that the bainitic ferrite develops by a displacive mechanism rather than a diffusional mechanism.

UR - http://www.scopus.com/inward/record.url?scp=0028495606&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0028495606&partnerID=8YFLogxK

U2 - 10.1007/BF02649049

DO - 10.1007/BF02649049

M3 - Article

VL - 25

SP - 2009

EP - 2016

JO - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science

JF - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science

SN - 1073-5623

IS - 9

ER -