Materials Algorithms Project
Program Library

Function MAP_STEEL_CG

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.

Top | Next

Purpose

To calculate the natural logarithm of the activity of carbon in austenite.

Top | Next | Prev

Specification

Top | Next | Prev

Description

MAP_STEEL_CG calculates the natural logarithm of the activity of carbon in austenite using the theory in [1, 2, 3]. The carbon-carbon interaction energy used is calculated according to [4].

Top | Next | Prev

References

1. J.R. Lacher, Proc. Camb. Phil. Soc. Math. Phys. Sci., 33, (1937), 518.
2. R.H. Fowler and E.A. Guggenheim, Statistical Thermodynamics, Cambridge University Press, New York, (1939).
3. G.J. Shiflet, J.R. Bradley, and H.I. Aaronson, Metall. Trans A, (1978), 999-1008.
4. H.K.D.H. Bhadeshia, Metal Science, 14, (1980), 230-232.

Top | Next | Prev

Parameters

Input parameters

X - real

X is the carbon concentration in austenite, x^gamma (in mole fraction).

T - real

T is the absolute temperature (in kelvin).

W - real

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

R - real

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

Output parameters

MAP_STEEL_CG - real

MAP_STEEL_CG is the natural logarithm of the activity of iron in austenite.

Top | Next | Prev

Error Indicators

None.

Top | Next | Prev

Accuracy

If X <= 10^-10, then MAP_STEEL_CG is set to 10^-10. References [3,4] give an estimate of the accuracy of the theory involved.

Top | Next | Prev

Further Comments

None.

Top | Next | Prev

Example

1. Program text

       DOUBLE PRECISION X,T,W,R,MAP_STEEL_CG,XCG
       INCLUDE 'map_constants_gas.f'
       READ (5,*) X,T,W
       XCG=MAP_STEEL_CG(X,T,W,R)
       WRITE (6,10) XCG
10     FORMAT ('XCG = ',D13.5)
       STOP
       END

2. Program data

0.11871D-01   931.0   8352.3

3. Program results

XCG = -0.95126D+00

Top | Next | Prev

Auxiliary Routines

None.

Top | Next | Prev

Keywords

activity, carbon, austenite

Top | Next | Prev

Download

Download source code

Top | Prev