H.K.D.H. Bhadeshia,
Phase Transformations Group,
Department of Materials Science and Metallurgy,
University of Cambridge,
Cambridge, U.K.
Added to MAP: June 1999
To calculate the carbon concentration and the lattice parameter of carbon-enriched austenite, at a specified temperature, after partial transformation to ferrite has occurred.
Language: | FORTRAN |
Product form: | Source code |
SUBROUTINE MAP_STEEL_PARAM(AGTX,AGT,AAT,VA,XBAR,XALPHA,XG, & EXG,T,AV,RTEMP) DOUBLE PRECISION AGTX,AGT,AAT,VA,XBAR,XALPHA,XG,EXG,T,AV,RTEMP
This subroutine is used in the analysis of the transformation from austenite to ferrite by program MAP_STEEL_DILAT. It obtains values for the carbon concentration and the lattice parameter of carbon-enriched austenite, at a temperature T, due to partial transformation of the austenite to ferrite, by solving iteratively equations 5 and 8 in reference 1:
where agT and ag are the austenite lattice parameters at temperature T before and after carbon enrichment; TRT is room temperature; woc and wc are the weight fractions of carbon in the austenite before and after enrichment; eg is the thermal expansion coefficient of austenite; Cc is the change in the austenite lattice parameter caused by the addition of unit concentration of carbon; wac is the carbon fraction in the ferrite; Va is the volume fraction of the ferrite; pa and pg are the densities of ferrite and austenite. A value of 3.3Å is used for Cc [2]. The densities are calculated from the lattice parameters, where it is assumed that all the atoms are Fe and no corrections are made for the compositional differences between the phases.
None.
No information supplied.
T and RTEMP may be given in either Kelvin or °C, provided that the same units are used for both parameters.
DOUBLE PRECISION AGTX,AGT,AAT,VA,XBAR,XALPHA,XG DOUBLE PRECISION EXG,T,AV,RTEMP C C AV is the Avogadro constant (in 1/(mole) C AV=6.0221367D+23 C WRITE(*,*) 'Input AGT, AAT, VA, EXG:' READ (*,*) AGT,AAT,VA,EXG WRITE(*,*) 'Input XBAR, XALPHA, T:' READ (*,*) XBAR,XALPHA,T RTEMP = 25.0D+00 CALL MAP_STEEL_PARAM(AGTX,AGT,AAT,VA,XBAR,XALPHA, & XG,EXG,T,AV,RTEMP) WRITE (*,1) AGTX WRITE (*,2) XG STOP 1 FORMAT ('Lattice parameter of carbon-enriched austenite = ', & F8.4,' Angstroms') 2 FORMAT ('Carbon concentration in the austenite = ', & F8.4,' wt%') END
Input AGT, AAT, VA, EXG: 3.6091 2.8853 6.66D-3 2.4559D-5 Input XBAR, XALPHA, T: 0.158 0.0156 349.0
Lattice parameter of carbon-enriched austenite = 3.6091 Angstroms Carbon concentration in the austenite = 0.1589 wt%
None.
enriched, austenite, ferrite, lattice parameter, carbon, concentration
MAP originated from a joint project of the National Physical Laboratory and the University of Cambridge.
MAP Website administration / map@msm.cam.ac.uk