MODELING OF THE INTERACTIONS BETWEEN B4C AND STAINLESS-STEEL AT HIGH-TEMPERATURES

Results of detailed chemical-analytical examinations of B4C/stainless steel (s.s.) reaction couples obtained at temperatures of 1000, 1100 and 1200 degrees C, and a theoretical model developed on the basis of these results, which describes the reaction layers growth kinetics, are presented. The examinations were carried out by AES and XMA methods to measure concentration profiles of different elements in the various phases and the thicknesses of the formed reaction layers as function of time to determine the growth kinetics. A new approach for modelling of diffusion mass transfer through a two-phase zone in multicomponent systems is further developed for the description of the growth kinetics of the reaction layer consisting of Me(2)B (Me = Fe, Cr, Ni) precipitates in the stainless steel matrix. Diffusion coefficients of Cr in all phases of the reaction zone are calculated. These data together with the measured boundary concentrations of the elements allow the complete description of the B4C/s.s. interaction kinetics at the examined test temperatures by the proposed model.