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Program MAP_STEEL_AE3PROG

  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

A.A.B. Sugden and H.K.D.H. Bhadeshia,
Phase Transformations Group,
Department of Materials Science and Metallurgy,
University of Cambridge,
Cambridge, U.K.

Program added: May 1999

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Purpose

To calculate the Ae3 temperature of low alloy steels containing Mn, Si, Ni, Cr, Mo, Cu, V, Nb, W, Co and C as a function of the carbon concentration between 0 and 0.5wt%.

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Specification

Complete program.

Language:FORTRAN
Product form:Source code.

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Description

Established thermodynamic procedures have been used to estimate the liquidus, solidus and Ae3 transformation temperatures for multi-component steels [1]. The program calculates the temperature deviation of the phase boundaries in the steel from that of the Fe-C system by using the analysis of Kirkaldy and Bagnis [2], which is based on equating the chemical potentials of the two phases at the equilibrium temperature. This analysis calculates the temperature deviation which results from the addition of each alloying component separately to the Fe-C system. The temperature changes in a multi-component alloy is then equal to the sum of the changes due to individual alloy additions, provided the solute-solute interactions are negligible. The resulting expression for the temperature deviation is:

dT = R To2 [ AMnXMn + ASiXSi + ANiXNi + ... + AWXW ] ,

where Xi is the mole fraction of component i, the summation being made over all the alloying components, and To is the corresponding temperature of the phase boundary in the Fe-C system. Ai is a function of the partition coefficient of component i, (see also equation 11 of reference 1), temperature, mole fraction of carbon, the change in the Gibbs free energy for the two phases, the standard molar enthalpy changes and the Wagner interaction coefficients of the alloying components.

The analysis used by Kirkaldy and Bagnis [2] has been modified and extended here in several ways:

The program calculates the Ae3 temperature for a range of values of carbon content between 0 and 0.5 wt%. As the equations being evaluated are a function of temperature, the calculations are iterated, with To as the initial value, until a change in temperature of less than 0.1K between successive iterations is obtained.

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References

  1. A.A.B. Sugden and H. K. D. H. Bhadeshia, 1989, Mat. Sci. and Tech., 5, 977.
  2. J.S. Kirkaldy and E. Baganis, 1978, Metall. Trans. A, 9, 495.
  3. H. K. D. H. Bhadeshia and D. V. Edmonds, 1980, Acta Metall., 28, 1265.
  4. L. Kaufman, E.V. Clougherty and R.J. Weiss, 1963, Acta Metall., 11, 323.
  5. L. Kaufman and H. Bernstein, 1970, Refractory Materials, New York: Academic Press, Vol. 4, 19.
  6. J.B. Gilmour, G.R. Purdy and J.S. Kirkaldy, 1972, Metall. Trans., 3, 1455.

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Parameters

Input parameters

Steel content: wt% of Mn, Si, Ni, Cr, Mo, Cu, V, Nb, W and Co in that order. The total solute content should be < 6wt% and the Si content < 1wt%.

Output parameters

The Ae3 temperature is calculated for a range of carbon concentrations between 0 and 0.5 wt%. For each value of the carbon wt% the program outputs the following parameters:

Carbon concentration (wt%)
The Ae3 temperature (° C)
A(c) - the partition coefficient for carbon
The partition coefficient of any solute present:
A(2) - Mn
A(3) - Si
A(4) - Ni
A(5) - Cr
A(6) - Mo
A(7) - Cu
A(8) - V
A(9) - Nb
A(10) - W
A(11) - Co

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Error Indicators

None.

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Accuracy

The calculations assume that the solute-solute interaction is negligible. This assumption has been found to be valid for a total alloying element content of less than about 6 wt%, provided the silicon content is < 1wt% [2]. Comparison of calculated results and experimental results give a standard error of ± 10 ° C.

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Further Comments

None.

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Example

1. Program text

Complete program.

2. Program data

 Input  Mn  Si  Ni  Cr  Mo  Cu  V  Nb  W  Co wt%:
       2.0 0.1  0   0   0   0   0   0  0   0

3. Program results


 --------------------------------------------------------------
      A   e   3        P    R    O    G    R    A    M
 --------------------------------------------------------------
 The steel contains:
 2.00 wt% manganese
 0.10 wt% silicon

   +---------------------------+----------------------------+
       Wt%C       T/degreesC     Partition coefficients
   +---------------------------+----------------------------+
      0.00        875.2            A(c) : 0.063
                                   A(2) : 0.718
                                   A(3) : 1.167
      0.01        869.6            A(c) : 0.061
                                   A(2) : 0.705
                                   A(3) : 1.165
      0.02        864.6            A(c) : 0.060
                                   A(2) : 0.693
                                   A(3) : 1.164
      0.03        860.2            A(c) : 0.058
                                   A(2) : 0.684
                                   A(3) : 1.162
      0.04        860.7            A(c) : 0.065
                                   A(2) : 0.746
                                   A(3) : 1.175
      0.05        855.6            A(c) : 0.057
                                   A(2) : 0.672
                                   A(3) : 1.160
      0.06        853.1            A(c) : 0.056
                                   A(2) : 0.666
                                   A(3) : 1.158
      0.07        850.6            A(c) : 0.056
                                   A(2) : 0.661
                                   A(3) : 1.157
      0.08        848.2            A(c) : 0.055
                                   A(2) : 0.655
                                   A(3) : 1.156
      0.09        845.9            A(c) : 0.054
                                   A(2) : 0.650
                                   A(3) : 1.155
      0.10        843.6            A(c) : 0.054
                                   A(2) : 0.644
                                   A(3) : 1.153
      0.11        841.4            A(c) : 0.053
                                   A(2) : 0.638
                                   A(3) : 1.152
      0.12        839.2            A(c) : 0.052
                                   A(2) : 0.634
                                   A(3) : 1.151
      0.13        837.1            A(c) : 0.052
                                   A(2) : 0.629
                                   A(3) : 1.149
      0.14        835.0            A(c) : 0.051
                                   A(2) : 0.624
                                   A(3) : 1.148
      0.15        832.9            A(c) : 0.051
                                   A(2) : 0.619
                                   A(3) : 1.147
      0.16        830.9            A(c) : 0.050
                                   A(2) : 0.615
                                   A(3) : 1.146
      0.17        828.9            A(c) : 0.050
                                   A(2) : 0.610
                                   A(3) : 1.144
      0.18        827.0            A(c) : 0.049
                                   A(2) : 0.606
                                   A(3) : 1.143
      0.19        825.1            A(c) : 0.049
                                   A(2) : 0.601
                                   A(3) : 1.142
      0.20        823.3            A(c) : 0.048
                                   A(2) : 0.597
                                   A(3) : 1.141
      0.21        821.4            A(c) : 0.048
                                   A(2) : 0.593
                                   A(3) : 1.139
      0.22        819.6            A(c) : 0.047
                                   A(2) : 0.589
                                   A(3) : 1.138
      0.23        817.9            A(c) : 0.047
                                   A(2) : 0.584
                                   A(3) : 1.137
      0.24        816.1            A(c) : 0.046
                                   A(2) : 0.580
                                   A(3) : 1.136
      0.25        814.4            A(c) : 0.046
                                   A(2) : 0.576
                                   A(3) : 1.134
      0.26        812.8            A(c) : 0.045
                                   A(2) : 0.572
                                   A(3) : 1.133
      0.27        811.2            A(c) : 0.045
                                   A(2) : 0.568
                                   A(3) : 1.131
      0.28        809.6            A(c) : 0.045
                                   A(2) : 0.564
                                   A(3) : 1.130
      0.29        808.0            A(c) : 0.044
                                   A(2) : 0.560
                                   A(3) : 1.129
      0.30        806.4            A(c) : 0.044
                                   A(2) : 0.557
                                   A(3) : 1.127
      0.31        804.9            A(c) : 0.043
                                   A(2) : 0.553
                                   A(3) : 1.126
      0.32        803.4            A(c) : 0.043
                                   A(2) : 0.549
                                   A(3) : 1.125
      0.33        801.9            A(c) : 0.043
                                   A(2) : 0.546
                                   A(3) : 1.124
      0.34        800.4            A(c) : 0.042
                                   A(2) : 0.542
                                   A(3) : 1.122
      0.35        798.9            A(c) : 0.042
                                   A(2) : 0.539
                                   A(3) : 1.121
      0.36        797.5            A(c) : 0.042
                                   A(2) : 0.536
                                   A(3) : 1.120
      0.37        796.1            A(c) : 0.041
                                   A(2) : 0.532
                                   A(3) : 1.118
      0.38        794.7            A(c) : 0.041
                                   A(2) : 0.529
                                   A(3) : 1.117
      0.39        793.4            A(c) : 0.041
                                   A(2) : 0.526
                                   A(3) : 1.116
      0.40        792.0            A(c) : 0.041
                                   A(2) : 0.523
                                   A(3) : 1.114
      0.41        790.7            A(c) : 0.040
                                   A(2) : 0.520
                                   A(3) : 1.113
      0.42        789.4            A(c) : 0.040
                                   A(2) : 0.517
                                   A(3) : 1.112
      0.43        788.1            A(c) : 0.040
                                   A(2) : 0.514
                                   A(3) : 1.111
      0.44        786.8            A(c) : 0.039
                                   A(2) : 0.511
                                   A(3) : 1.109
      0.45        785.5            A(c) : 0.039
                                   A(2) : 0.508
                                   A(3) : 1.108
      0.46        784.3            A(c) : 0.039
                                   A(2) : 0.505
                                   A(3) : 1.107
      0.47        783.0            A(c) : 0.039
                                   A(2) : 0.503
                                   A(3) : 1.106
      0.48        781.8            A(c) : 0.038
                                   A(2) : 0.500
                                   A(3) : 1.104
      0.49        780.6            A(c) : 0.038
                                   A(2) : 0.497
                                   A(3) : 1.103
      0.50        779.4            A(c) : 0.038
                                   A(2) : 0.494
                                   A(3) : 1.102

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Auxiliary Routines

NAG library routine E02BBF. This routine is not included with this program. It is used to evaluate a cubic spline from the spline coefficients for delta oHo from Kaufman et al.[4].

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Keywords

Ae3 temperature, low alloy steel, partition coefficient

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Download

Download source code

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