Actual Problems in Machine Building 2016 No. 3

Актуальные проблемы в машиностроении. 2016. №3 Материаловедение в машиностроении ____________________________________________________________________ 491 SURFACE SATURATION OF LOW-CARBON STEEL WITH BORON AND ALUMINUM FROM PASTES IN THERMOCYCLING Polyansky I. P. 1 , Engineer, e-mail: i.polyansky@mail.ru Sizov I. G. 1 , D.Sc. (Engineering), Professor, e-mail: sigperlit@mail.ru Mishigdorzhiyn U. L. 1 , Ph.D, Senior Researcher, e-mail: druh@mail.ru Leyens C. 2 , D.Sc. (Engineering), Professor, e-mail: christoph.leyens@tu-dresden.de Vetter B. 2 , D.Sc. (Engineering), Principal engineer, e-mail: birgit.vetter@tu-dresden.de 1 East Siberia State University of Technology and Management, 40V Kluchevskaya st., Ulan-Ude, 670013, Russian Federation 2 Technische Universität Dresden, 10 Helmholtzstraße, Dresden, 01069, Germany Abstract Isothermal and thermocycle boroaluminizing of the steel 20 is carried out, the thermocycling temperature range of the coated samples is determined, the comparative analysis of microstructures according to the treatment mode is given, the distribution of microhardness and the elemental composition of the diffusion layer depth are studied, oxidation of the boroaluminized layers on the steel 20 is investigated. It is found that the combination of chemical and thermocycle treatments contributes to a better formation of the boroaluminized layer, particularly, it produces a more aluminum enriched phase in the diffusion layer, such as FeAl 3 and Fe 2 Al 5 , which in turn leads to an increase in microhardness and oxidizing environment resistance at high temperatures. Also it is established that thermocycle treatment brings to the structure refinement of a saturable material, which has a positive effect on mechanical properties of the substrate. Keywords thermochemical treatment, paste boroaluminizing, thermocycling, microhardness, electron microprobe analysis, oxidation resistance Funding The work was supported by the Russian President's grant for state support of young Russian scientists - PhD (Competition - MK-2015)