Materials Algorithms Project
Program Library

Subroutine MAP_STEEL_FERR

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.

Added to MAP: June 1999.

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Purpose

To calculate the ferrite lattice parameter at room temperature of an alloy steel.

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Specification

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Description

MAP_STEEL_FERR is used in the analysis of the transformation from austenite to ferrite. It calculates the lattice parameter of the ferrite phase at room temperature (25°C), using equation 1 in reference 1, given the mean concentrations of C, Si, Mn, Ni, Mo, Cr and V in the material and the C concentration in the ferrite:

where x_i is the mole fraction of element i in the ferrite and a_Fe (nm) is the lattice parameter of pure iron at room temperature. The concentrations of the solute elements other than C are assumed to be evenly distributed between the phases. The effect of molybdenum is derived from reference 2, the vanadium coefficient is from reference 3 and the expansion due to carbon is taken from reference 4. A value of 2.8664 Å for pure iron is given by reference 5.

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References

1. H.K.D.H Bhadeshia, S.A. David, J.M. Vitek and R.W. Reed, 1991, Materials Science and Technology, 7, 686-698.
2. F. Wever, 1928, Zeitschrift für Metallkunde, 20, 363-370.
3. Hume-Rothery and Sutton, Structure of Iron and Alloys.
4. C.S. Roberts, 1953, Trans. AIME, 197, 203.
5. National Bureau of Standards (USA), 1955, Circ. 539, 43.

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Parameters

Input parameters

C - real

C is the mean carbon concentration (weight percent) of the material.

SI - real

SI is the silicon concentration (weight percent).

MN - real

MN is the manganese concentration (weight percent).

NI - real

NI is the nickel concentration (weight percent).

MO - real

MO is the molybdenum concentration (weight percent).

CR - real

CR is the chromium concentration (weight percent).

V - real

V is the vanadium concentration (weight percent).

CALP - real

CALP is the concentration of carbon dissolved in ferrite (weight percent).

PFE - real

PFE is the lattice parameter of pure iron at room temperature (metres). Reference 5 gives a value of 2.8664 Å.

Output parameters

P - real

P is the ferrite lattice parameter at 298K (metres).

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Error Indicators

None.

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Accuracy

No information supplied.

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Further Comments

The remaining wt.% of the steel is assumed to be iron. The calculations of the solute atom concentrations assume that the C concentration is small.

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Example

1. Program text

      DOUBLE PRECISION C,SI,MN,NI,MO,CR,V,CALP,PFE,P
      PFE = 2.8664D-10
      WRITE(*,*) 'Input C  Si  Mn  Ni  Mo  Cr  V  wt%:'
      READ (*,*) C,SI,MN,NI,MO,CR,V
      WRITE(*,*) 'Input C concentration dissolved in ferrite (wt%):'
      READ (*,*) CALP
      CALL MAP_STEEL_FERR(C,SI,MN,NI,MO,CR,V,CALP,PFE,P)
      P = P * 1D10
      WRITE (*,1) P
    1 FORMAT ('Ferrite lattice parameter at 298K = ',F8.5,' Angstroms')
      STOP
      END

2. Program data

 Input C  Si  Mn  Ni  Mo  Cr  V  wt%:
     0.05 0.5  1   0   0 0.01 0
 Input C concentration dissolved in ferrite (wt%):
 0.02

3. Program results

Ferrite lattice parameter at 298K =  2.86731 Angstroms

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Auxiliary Routines

None.

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Keywords

ferrite, lattice parameter

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Download

Download source code

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