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Subroutine MAP_STEEL_AXTO

  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.

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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 carbon concentration (mole fraction) at the T0 phase
boundary at a specified temperature.

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Specification

SUBROUTINE MAP_STEEL_AXTO(H,S,H1,S1,XTO,T,W,W1,F,
&AJ,AJ1,STORE,JN,J,R)

DOUBLE PRECISION H,S,H1,S1,XTO,T,W,W1,F,AJ,AJ1,
&STORE,R

DOUBLE PRECISION MAP_STEEL_FTO1, MAP_STEEL_G91

INTEGER J, JN

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Description

MAP_STEEL_AXTO calculates the carbon concentration (mole fraction) at the T0
phase boundary at a specified temperature. Newton's iterative method is used
to refine an initial guess.

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References

1. 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, 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, Jmol-1).

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).

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.

STORE - real
     STORE is the stored energy (in joules per mole, Jmol-1).

JN - integer
     JN is the maximum number of iterations.

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

Output parameters

XTO - real
     XTO is the carbon concentration at the T0 boundary.

J - integer
     J is the number of iterations performed.

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Error Indicators

None.

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Accuracy

No information supplied.

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Further Comments

See also subroutine MAP_STEEL_OMEGA and function MAP_STEEL_ENERGY.

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Example

1. Program text

       DOUBLE PRECISION H,S,H1,S1,XTO,T,W,W1,F,AJ,AJ1,STORE,R
       INTEGER J,JN
       INCLUDE 'map_constants_gas.f'
       READ (5,*) H,S,H1,S1,T,W,W1
       READ (5,*) F,AJ,AJ1,STORE
       READ (5,*) JN
       CALL MAP_STEEL_AXTO(H,S,H1,S1,XTO,T,W,W1,F,AJ,AJ1,STORE,
&      JN,J,R)
       WRITE (6,10) XTO
       WRITE (6,20) J
10     FORMAT ('Carbon concentration at T0 boundary is ',F8.5)
20     FORMAT (I4,' iterations were required for convergence')
       STOP
       END

2. Program data

None supplied.

3. Program results

None supplied.

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Auxiliary Routines

MAP_STEEL_FTO1
MAP_STEEL_G91

Keywords

carbon, T0 boundary

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The MAP Project originated from a joint project of the National Physical
Laboratory and the University of Cambridge.

MAP Website administration / map@msm.cam.ac.uk

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