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Function MAP_STEEL_FTO1

  1. Provenance of code.
  2. Purpose of code.
  3. Specification.
  4. Description of subroutine's operation.
  5. References.
  6. Parameter descriptions.
  7. Error indicators.
  8. Accuracy estimate.
  9. Any additional information.
  10. Example of code
  11. Auxiliary subroutines required.
  12. Keywords.
  13. Download source code.
  14. Links.

Provenance of Source Code

H.K.D.H. Bhadeshia,
Phase Transformations Group,
Department of Materials Science and Metallurgy,
University of Cambridge,
Cambridge, U.K.

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Purpose

To calculate the free energy change accompanying the transformation from austenite to ferrite of the same chemical composition, including a Zener ordering term.

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Specification

Language:FORTRAN
Product form:Source code

FUNCTION MAP_STEEL_FTO1(H,S,X,T,W,W1,H1,S1,F,AJ,AJ1,R)

DOUBLE PRECISION H,S,X,T,W,W1,H1,S1,F,AJ,AJ1,R

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Description

MAP_STEEL_FTO1 calculates the free energy change accompanying the transformation from austenite to ferrite of the same chemical composition, including a Zener ordering term. The latter describes the ordering of carbon atoms that leads to the the body-centred cubic lattice of ferrite becoming body-centred tetragonal. The degree of ordering increases as the carbon concentration increases, or as the transformation temperature decreases.

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References

  1. C. Zener, Trans. AIME, 167, (1946), 550.
  2. J.C. Fisher, Metals Transactions, 185, (1949), 688-690.
  3. H.K.D.H. Bhadeshia and D.V. Edmonds, Acta Metallurgica, 28, (1980), 1265-1273.

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Parameters

Input parameters

H - real
H is the excess partial molar enthalpy of solution of carbon in austenite (in joules per mole, Jmol-1).

S - real
S is the excess partial molar entropy of solution of carbon in austenite (in joules per mole per kelvin, Jmol-1K-1).

X - real
X is the mole fraction of carbon in the ferrite.

T - real
T is the temperature (in kelvin).

W - real
W is the carbon-carbon interaction energy in austenite (in joules per mole, Jmol-1).

W1 - real
W1 is the carbon-carbon interaction energy in ferrite (in joules per mole, Jmol-1).

H1 - real
H1 is the excess partial molar enthalpy of solution of carbon in ferrite (in joules per mole, Jmol-1).

S1 - real
S1 is the excess partial molar entropy of solution of carbon in ferrite (in joules per mole per kelvin, Jmol-1K-1).

F - real
F is the energy (in joules).

AJ - real
AJ = 1 - e(W/RT), where R is the universal gas constant.

AJ1 - real
AJ1 = 1 - e(W1/RT), where R is the universal gas constant.

R - real
R is the universal gas constant (in joules per mole per kelvin, Jmol-1K-1).

Output parameters

MAP_STEEL_FTO1 - real
MAP_STEEL_FTO1 is the free energy change accompanying the transformation from austenite to ferrite of the same chemical composition.

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Error Indicators

None.

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Accuracy

No information supplied.

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Further Comments

None.

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Example

1. Program text

       DOUBLE PRECISION H,S,X,T,W,W1,H1,S1,F,AJ,AJ1,R,XFTO
       DOUBLE PRECISION MAP_STEEL_FTO1
       INCLUDE 'map_constants_gas.f'
       READ (5,*) H,S,H1,S1,W,W1
       READ(5,*) X,T,F,AJ,AJ1
       XFTO=MAP_STEEL_FTO1(H,S,X,T,W,W1,H1,S1,F,AJ,AJ1,R)
       WRITE (6,*) XFTO
       STOP
       END

2. Program data

None supplied.

3. Program results

None supplied.

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Auxiliary Routines

None.

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Keywords

austenite, ferrite, free energy change

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Download

Download source code

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