Carbon redistribution in austenitic steel weldments

Abstract

In parts I and II of our papers (Czech. J. Phys.35 (1985) 1355 and36 (1986) 514) concerning carbon redistribution in austenitic steel weldments the stationary (SM) and quasistationary (QSM) models have been developed and applied in the analysis of Darken's and our own data. It was necessary, in deriving the quoted SM and QSM, to introduce some simplifying presumptions. The present part III gives the general solution (GS) of the problem. It is based on the theory of thermodynamics irreversible processes, and the resulting system of differential equations is integrated numerically. The properties and chances of the GS are demonstrated in comparison with experimental data and by different examples of the prediction of carbon redistribution. The events of the non-zero thermodynamic (εskCi) and diffusion (βskCi) interaction coefficients, of the Kirkendall effect, of the non-constant atomic volume effect and of the different Wagner's and Zupp-Stevenson expressions of carbon activity coefficientγ _C are discussed.