L.P. Shestopalova, L.G. Petrova, A.Yu. Malachov

In the paper the up-to-date methods of analyses of structure and phase composition are represented applied to modified layers in steels formed as the result of different kinds of thermo-chemical treatment. The usage of a complex of methods combining metallographic investigations, analyses of phase composition by diffraction and spectral methods, analyses of nanostructure of metals by methods of electronic microscopy allows to receive the most complicated vision of modified layers of strengthened steels on micro- and nano-scaled levels. For investigation of ultra-dispersed fractions of precipitated phases, formed in modified layers in metal-based materials that can-t be visualized by classic methods the method of electrographic analyze is suggested. The method gives the opportunity to analyze structural and phase transformations in strengthened zones and also to determine stresses in modified layer on the basis of the specifics of colored electrographic picture. Computer treatment of digital electrographic image allows to occur automatic quantitative express-analyses of structure and phase composition. The methods of analyses studied in the paper give images of distribution of phases in the modified layer and their quantitative composition, that allows to predict possible working parameters of the layer.