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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.

Estimates the equilibrium partition coefficient.

Language: | FORTRAN |

Product form: | Source code |

SUBROUTINE MAP_STEEL_EDC(C,SI,MN,NI,MO,CR,V,&

& KC,KSI,KMN,KNI,KMO,KCR,KV,R,M)

DOUBLE PRECISION C,SI,MN,NI,MO,CR,V,KC,KSI,KMN,KNI,&

& KMO,KCR,KV,R,M

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

k0(X) = exp[Delta^{o}G(X)/(RT)]

- where :-
- k0(X) is the equilibrium partition coefficient for alloy element X
- Delta
^{o}G(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
^{o}G(Si) = 4.187(3.9T - 8200) - Delta
^{o}G(Mn) = 4.187(-2.308T + 3100) - Delta
^{o}G(Ni) = 4.187(-0.38T - 2120) - Delta
^{o}G(Cr) = 4.187(2.19T - 4600) - Delta
^{o}G(Mo) = 4.187(2.29T - 6600) - Delta
^{o}G(V) = 4.187(2.3T - 5100)

- 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).
- L. Smrha, Solidification and crystallisation of steel ingots, SNTL, Prague, (1983).

**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
^{-1}K^{-1}).

**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.

None.

No information supplied.

None.

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

0.04 0.35 1.0 1.96 0.35 0.38 0.01

1.0000000000000 0.70926988553226 0.74832335748641 0.45478740786807 0.49458284876864 0.82563667673227 0.75812544661665

None.

equilibrium partition coefficient, solidification-induced segregation

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