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Subroutine MAP_STEEL_TTTT

  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 incubation times due to displacive transformations.

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Specification

Language:FORTRAN
Product form:Source code

SUBROUTINE MAP_STEEL_TTTT(T,GMAX,SHEART,DIFFT,R)

DOUBLE PRECISION T,GMAX,SHEART,DIFFT,R

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Description

MAP_STEEL_TTTT calculates the incubation period on an isothermal transformation diagram for two C-curves. SHEART represents the kinetics of displacive transformations such as Widmanstätten ferrite, bainite and acicular ferrite.

SHEART = e(243200/RT) - 135 + 20log(T) - 5log(|GMAX|)

DIFFT represents the kinetics of displacive transformations such as allotriomorphic ferrite and pearlite.

DIFFT = e(603100/RT) - 190.5 + 20log(T) - 4log(|GMAX|)

Both C-curves are for zero percent transformation (the initiation of reaction).

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References

  1. H.K.D.H. Bhadeshia, Metal Science, 16, (1982), 159-165.

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Parameters

Input parameters

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

GMAX - real
GMAX is the product of the temperature (in kelvin), the gas constant, and the natural logarithm of the activity of carbon in ferrite divided by the activity of carbon in austenite.

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

Output parameters

SHEART - real
SHEART is the incubation time (in seconds) for the C-curve for displacive reactions.

DIFFT - real
DIFFT is the incubation time (in seconds) for the C-curve for reconstructive reactions.

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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 T,GMAX,SHEART,DIFFT,R
       INCLUDE 'map_constants_gas.f'
       READ (5,*) T,GMAX
       CALL MAP_STEEL_TTTT(T,GMAX,SHEART,DIFFT,R)
       WRITE (6,*) SHEART,DIFFT
       STOP
       END

2. Program data

None supplied.

3. Program results

None supplied.

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Auxiliary Routines

None.

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Keywords

displacive transformations, ferrite, bainite, pearlite, incubation time

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Download

Download source code

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