H.K.D.H. Bhadeshia,
Phase Transformations Group,
Department of Materials Science and Metallurgy,
University of Cambridge,
Cambridge, U.K.
Calculates the Gibbs Thompson critical radius for zero growth of a ferrite plate in austenite at a given temperature and the equilibrium concentration at the plate tip.
Language: | FORTRAN |
Product form: | Source code |
If the equilibrium carbon concentration of austenite is x[gamma alpha], and a ferrite plate has a radius of curvature of rho at its tip, then the austenite concentration in local equilibrium with this tip (taking account of the Gibbs-Thompson effect) is xrho, where:-
where sigma is the alpha/gamma interfacial energy (J/m2), f is the activity coefficient of austenite, Vmol is the molar volume of ferrite and gamma, the capillarity constant, is :-
The critical radius at which the growth of the plate is zero is reached when xrhoc = x, i.e. when :-
None.
No information supplied.
None.
DOUBLE PRECISION RADIUS, XMAX, XALPHA, XBAR, T, R, XMAXR, W, & SIG, MOLVOL, CAPCON, EPSI INCLUDE 'map_constants_gas.f' READ (5,*) XMAX, XALPHA, XBAR READ (5,*) T, W, SIG CALL MAP_STEEL_RRAD(RADIUS, XMAX, XALPHA, XBAR, T, R, XMAXR, W, & SIG, MOLVOL, CAPCON, EPSI) WRITE (6,10) RADIUS, XMAXR, MOLVOL, CAPCON, EPSI 10 FORMAT('Gibbs Thompson critical radius = ',D13.5,' metres' & 'Equilibrium concentration at plate tip = ',D13.5 & 'Molar volume of ferrite = ',D13.5,' cubic metres per mole' & 'Capillarity constant = ',D13.5 & 'Non-ideality parameter = ',D13.5) STOP END
0.51111D-01 0.74501D-03 0.13738D-01 901.15 8352.3 0.2
Gibbs Thompson critical radius = 0.30652D-08 metres Equilibrium concentration at plate tip = 0.45787D-01 Molar volume of ferrite = 0.72412D-05 cubic metres per mole Capillarity constant = -0.22413D-08 Non-ideality parameter = 0.16247D+01
Gibbs Thompson, critical radius, equilibrium concentration, capillarity constant, non-ideality parameter, ferrite, austenite, tip, plate
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