Materials Algorithms Project
Program Library

Subroutine MAP_STEEL_EDC

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

K. Ichikawa (Nippon Steel Corporation) and 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

Estimates the equilibrium partition coefficient.

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Specification

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Description

The equilibrium partition coefficient for alloy X is given by:-

k0(X) = exp[Delta^oG(X)/(RT)]

where :-

k0(X) is the equilibrium partition coefficient for alloy element X

Delta^oG(X) is the Gibbs free energy change per mole that occurs when transforming the pure element X from the delta ferrite to the liquid state,

R is the universal gas constant and

T is the absolute temperature.

The value of k0(C) is assumed to be 1 because of the ready diffusion of carbon.

The formulae used to calculate the Gibbs free energy changes are:-

Delta^oG(Si) = 4.187(3.9T - 8200)

Delta^oG(Mn) = 4.187(-2.308T + 3100)

Delta^oG(Ni) = 4.187(-0.38T - 2120)

Delta^oG(Cr) = 4.187(2.19T - 4600)

Delta^oG(Mo) = 4.187(2.29T - 6600)

Delta^oG(V) = 4.187(2.3T - 5100)

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References

1. J.S. Kirkaldy, B.A. Thomson, and E.A. Baganis, "Prediction of multicomponent equilibrium and transformation diagrams for low-alloy steel. Hardenability concepts with applications to steels.", AIME, USA, (1978).
2. L. Smrha, Solidification and crystallisation of steel ingots, SNTL, Prague, (1983).

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Parameters

Input parameters

C - real

C is the carbon concentration (in weight percent).

SI - real

SI is the silicon concentration (in weight percent).

MN - real

MN is the manganese concentration (in weight percent).

NI - real

NI is the nickel concentration (in weight percent).

MO - real

MO is the molybdenum concentration (in weight percent).

CR - real

CR is the chromium concentration (in weight percent).

V - real

V is the vanadium concentration (in weight percent).

R - real

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

Output parameters

M - real

M is the melting temperature of the delta ferrite (in kelvin).

KC - real

KC is the equilibrium partition coefficient of carbon.

KSI - real

KSI is the equilibrium partition coefficient of silicon.

KMN - real

KMN is the equilibrium partition coefficient of manganese.

KNI - real

KNI is the equilibrium partition coefficient of nickel.

KMO - real

KMO is the equilibrium partition coefficient of molybdenum.

KCR - real

KCR is the equilibrium partition coefficient of chromium.

KV - real

KV is the equilibrium partition coefficient of vanadium.

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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 C,SI,MN,NI,MO,CR,V,R,M
       DOUBLE PRECISION KC,KSI,KMN,KNI,KMO,KCR,KV
       INCLUDE 'map_constants_gas.f'
       READ (5,*) C,SI,MN,NI,MO,CR,V
       CALL MAP_STEEL_EDC(C,SI,MN,NI,MO,CR,V,&
&      KC,KSI,KMN,KNI,KMO,KCR,KV,R,M)
       WRITE (6,*) KC,KSI,KMN,KNI,KMO,KCR,KV
       WRITE (6,10) M
10     FORMAT (5X,' Assumed melting point of delta ferrite ',F11.4)
       STOP
       END

2. Program data

0.04   0.35   1.0   1.96   0.35   0.38   0.01

3. Program results

1.0000000000000   0.70926988553226   0.74832335748641
0.45478740786807  0.49458284876864   0.82563667673227   0.75812544661665

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Auxiliary Routines

None.

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Keywords

equilibrium partition coefficient, solidification-induced segregation

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Download

Download source code

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