A thermodynamic study of inverse bainitic transformation

A thermodynamic study of inverse bainitic transformation The effect of Cr, Mn, and the isothermal holding temperature on inverse bainitic transformation in hypereutectoid steels is investigated. Thermodynamic driving force is calculated for the onset of nucleation of cementite and ferrite from parent austenite, Hultgren extrapolation of A e3 and A cm phase boundaries, and the molar Gibbs energy change for austenite to ferrite transformation. For a given carbon concentration above the eutectoid carbon concentration, inverse bainite is favored at a lower Cr and higher Mn concentrations in the steel. With the increase in Cr concentration, the inverse bainitic start temperature has been found to increase. Cr partitioning from parent austenite to form Cr7C3 or Cr23C6 occurs only at prolonged transformation time (10000 s and above), by when the inverse bainitic transformation is complete. Cementite is the favored carbide nucleating from parent austenite during the inverse bainitic transformation. With the increase in Mn concentration, both the inverse bainitic start and finish temperatures have been found to decrease. For a given chemical composition, inverse bainite is generally favored below the pearlitic transformation temperature. Inverse bainitic transformation gets suppressed when the isothermal transformation temperature is lowered, in which case conventional upper/lower bainite is the favored transformation product. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Journal of Materials Science Springer Journals

A thermodynamic study of inverse bainitic transformation

Loading next page...
 
/lp/springer_journal/a-thermodynamic-study-of-inverse-bainitic-transformation-30zH9FYN8w
Publisher
Springer US
Copyright
Copyright © 2018 by Springer Science+Business Media, LLC, part of Springer Nature
Subject
Materials Science; Materials Science, general; Characterization and Evaluation of Materials; Polymer Sciences; Continuum Mechanics and Mechanics of Materials; Crystallography and Scattering Methods; Classical Mechanics
ISSN
0022-2461
eISSN
1573-4803
D.O.I.
10.1007/s10853-018-2541-8
Publisher site
See Article on Publisher Site

Abstract

The effect of Cr, Mn, and the isothermal holding temperature on inverse bainitic transformation in hypereutectoid steels is investigated. Thermodynamic driving force is calculated for the onset of nucleation of cementite and ferrite from parent austenite, Hultgren extrapolation of A e3 and A cm phase boundaries, and the molar Gibbs energy change for austenite to ferrite transformation. For a given carbon concentration above the eutectoid carbon concentration, inverse bainite is favored at a lower Cr and higher Mn concentrations in the steel. With the increase in Cr concentration, the inverse bainitic start temperature has been found to increase. Cr partitioning from parent austenite to form Cr7C3 or Cr23C6 occurs only at prolonged transformation time (10000 s and above), by when the inverse bainitic transformation is complete. Cementite is the favored carbide nucleating from parent austenite during the inverse bainitic transformation. With the increase in Mn concentration, both the inverse bainitic start and finish temperatures have been found to decrease. For a given chemical composition, inverse bainite is generally favored below the pearlitic transformation temperature. Inverse bainitic transformation gets suppressed when the isothermal transformation temperature is lowered, in which case conventional upper/lower bainite is the favored transformation product.

Journal

Journal of Materials ScienceSpringer Journals

Published: Jun 6, 2018

References

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create lists to
organize your research

Export lists, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off