[en] Different regimes of electron-beam treatment (EBT) without the melting of steels 08Kh2G2F and 0.10C-Cr-Mn-V are investigated to clarify possibilities of superfine grain surface structure production. Irradiation of samples was conducted in the air by a continuous concentrated beam of 1.2 MeV electrons using the EhLV-6 commercial accelerator. As a result of EBT in the surface layer of the steels investigated regions with coarse- and fine-crystal martensite are formed. Austernitic grain size in the second region for all irradiation modes is 4-5 μm. Surface heating temperature decrease from 1400 to 900 deg C leads to the region size reduction up to the total disappearance of the region with the large-grain structure. In case of cyclic EBT superfine austenite grains of 1.3 (5 cycles) and 1.1 μm (10 cycles) were produced

[en] Possibilities of steel superficial hardening by a concentrated electron beam are studied. Experiments have been conducted since 1985 using the EhLV-6 accelerator with concentrated emission of the beam into atmosphere. Regimes ensuring the hardening and certain characteristic properties of the hardened layer are described

[en] A possibility of steel surface layer hardening by alloying using the relativistic electron energy is shown. Structure, hardness and hardened layer depth dependence on the treatment mode and initial temperature of steel under alloying with boron carbide and Cr+C and Cr+B₄C mixtures is investigated. The maximum hardening level is achieved under alloying with Cr and B₄C powder mixture which is connected with a large volumetric share of the second phase in the layer and chromium carboride isolation

[en] The investigation results on electron beam hardening of surface layers of carbon steel 50 and cast iron SCh30 are presented. It is shown that heat treatment with electron beam gives rise to essential hardening due to formation of highly dispersed martensitic structure. It is established that hardness, wear resistance and the depth of a zone of complete phase recrystallization are linearly dependent on the density of introduced energy on irradiation. Simulating calculations are performed for an electron beam induced temperature field at the surface

[en] The structure and properties of powder strengthening coatings (the mixture of B₄C, WC, TiC, Cr) on carbon steels produced by weld-surfacing with the help of a relativistic electron beam are investigated and established to be dependent on irradiation parameters and the composition of powder mixtures. To gain high wear resistance a content of chromium or tungsten carboboride Me₂₃(C,B)₆ in the coating should be as much as 45-50%. Small additions of FeV, FeTi and TiB₂ to an alloying powder mixture result in ultradispersed structure and enhanced wear resistance of electron beam fused coatings. The method is of high productivity and allows obtaining thick surface layers free of cracks and micropores

[en] Structure, phase composition, microhardness, and wear resistance of the coatings produced by electron- beam surfacing of refractory powders on Ti-based substrate have been investigated. It is shown that the coatings formed have a hypereutectic or eutectic structure on the base of carbides, nitrides, borides, and silicides of titanium. Correlation between the coatings wear resistance and volume fraction of the particles of strengthening phase inclusions in surfaced layer is pointed out

[en] A consideration is given to the influence of various conditions of electron beam weld-surfacing on the properties of surface layer (structure, thickness, hardness, wear resistance) of carbon steels 3 and 45. Prior to electron beam heating the steel surface was coated with various powder mixtures containing tungsten, chromium or boron carbides and borax as a protective additive against oxygen and nitrogen effects. Structure and phase composition of surface layer were investigated by the methods of metallography and X-ray diffraction analysis. The hardness and wear resistance were found to increase in all cases, but the degree of hardening was dependent on the powder composition. It is concluded about the efficiency of relativistic electron beam application for modification of steel surfaces

[en] The experiments with surfacing chromium carbide powder mixtures and chromium carbide onto St3 low-carbon steel in the relativistic electron beam have been carried out. The structure and phase composition of the surface layers have been investigated, the chromium content in them has been determined. The microhardness distribution has been studied, corrosion resistance and abrasive wear have been tested. It has been shown that wear-resistant of the surfaced layers is not only determined by hardness but also by the character of the formed structure. Corrosion resistance depends on the quantity of chromium in the surfaced mixture and increases with increase. We have selected a surfacing mode that allows one to obtain bifunctional coatings having both high wear and corrosion resistance. (authors)

[en] Structural changes running in a rail steel type M76 on electron beam quenching in the air are under study. The microhardness of a ∼1.2 mm thick hardened zone constitutes 800-900 HV. A short-term electron beam tempering makes possible decreasing microhardness down to ∼400-700 HV. It is established that the electron beam hardening ensures an increase of steel wear resistance by factors of ∼2-3 under the action of fixed and not strongly fixed abrasive particles. The data obtained allows one to recommend the method of electron beam processing for the hardening side faces of heads of rails

[en] By a method of vacuum-free electron beam surfacing of tungsten carbide powder on the plain carbon steel the coatings were formed. The structure, hardness and wear resistance of these coatings depends on specific surface energy of irradiation and the cooling rate of melt. It was shown that the structure 'carbide inclusions in austenite matrix' possesses the best properties. Such structure is similar to hard alloy structure, the functionality of which bases on compromise between the strength and elasticity. Heat treatment of fusion layers results in unification of fusion layers structure and increasing of there hardness and wear resistance. After doping of modifying agent additional increasing of properties occurs. (authors)