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Subroutine MAP_STEEL_MSTART

  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 and N.A. Chester,
Phase Transformations Group,
Department of Materials Science and Metallurgy,
University of Cambridge,
Cambridge, U.K.

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Purpose

To calculate the martensite-start temperature.

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Specification

Language:FORTRAN
Product form:Source code

SUBROUTINE MAP_STEEL_MSTART(T10,T20,W,W1,JTLOW,JTHIGH,MS,X1,JP)

DOUBLE PRECISION DCTEMP(100), FTO(100)
DOUBLE PRECISION AJ, AJ1, CONST, CORR, F, H, H1,
& KTEMP, MS, R, S, S1, SLOPE, T10, T20,
& W, W1, XTO, X1, XMS

DOUBLE PRECISION MAP_STEEL_ENERGY, MAP_STEEL_FTO1

INTEGER J, J1, J2, JP, JTLOW, JTHIGH,
& IL, ITLOW, ITHIGH, IT

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Description

MAP_STEEL_MSTART calculates the martensite-start temperature using theory based on [3]. This is also used in subroutine MAP_STEEL_BSMS, which calculates both Bs and Ms temperatures.

If the free energy of transformation from austenite to ferrite Delta G{gamma alpha} in pure iron is factorised into magnetic and non-magnetic components, then Delta TM and Delta TNM represent the temperature changes, caused by unit concentration x of substitutional solute, to the temperature at which Delta G{gamma alpha} is calculated.

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References

  1. G.J. Shiflet, J.R. Bradley and H.I. Aaronsson, Metallurgical Transactions A, 9A, (1978), 999.
  2. J.A. Lobo and G.H. Geiger, Metallurgical Transactions A, 7A, (1976), 1357 and 1359.
  3. H.K.D.H. Bhadeshia, Metal Science, 15, (1981), 175-180.

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Parameters

Input parameters

T10 - double precision
T10 = Delta TM - Delta TNM

T20 - double precision
T20 = Delta TM

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

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

JTLOW - integer
JTLOW is the lowest temperature (in kelvin) for which results are to be calculated.

JTHIGH - integer
JTHIGH is the highest temperature (in kelvin) for which results are to be calculated.

X1 - double precision
X1 is the carbon concentration (in mole fraction).

JP - integer
JP defines the amount of printing in subroutines called by this subroutine. A value of 1 means no printing.

Output parameters

MS - double precision
MS is the martensite-start temperature (in degrees centigrade).

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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

       PROGRAM MSTART
       IMPLICIT NONE
       DOUBLE PRECISION T10,T20,W,W1,MS,X1
       INTEGER JTLOW,JTHIGH,JP
C
       OPEN(3,FILE='data.dat')
C
       R = 8.3143D+00
C
       READ(3,*) T10
       READ(3,*) T20
       READ(3,*) W
       READ(3,*) W1
       READ(3,*) JTLOW
       READ(3,*) JTHIGH
       READ(3,*) X1
       READ(3,*) JP
C
       CALL MAP_STEEL_MSTART(T10,T20,W,W1,JTLOW,JTHIGH,MS,X1,JP)
C
       WRITE(6,1001) MS
C
       CLOSE(3)
       STOP
1001   FORMAT('MS is ',f6.2)
       END

2. Program data

Contained in ASCII data file 'data.dat'

-4.32D-02
-0.762
8488.89
48570
473
773
1.74D-02
1

3. Program results

MS is 320.34

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Auxiliary Routines

Functions:
MAP_STEEL_ENERGY
MAP_STEEL_FTO1

Utility Subroutines:
MAP_UTIL_ANALY

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Keywords

martensite, start temperature

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Download

Download source code

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

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