Electron-ion-plasma modification of the structure and properties of commercial steels

The work is devoted to the structural-phase analysis of steels of the austenitic and martensitic grade, irradiated with a high-intensity pulsed electron beam of the submillisecond duration of exposure in the mode of the surface layer melting. A thermodynamic analysis of phase transformations occurring during heat treatment in alloys of the composition Fe-Cr-C and Fe-Cr-Ni-C, which are the basis of steels 20X13 and 12X18H10T, is carried out. It is shown that formation of solid solutions on the basis of [alpha]-iron (BCC crystalline lattice) and [gamma]- iron (FCC crystalline lattice) as well as the entire range of carbide phases of a complex elemental composition (M[23]C[6], M[7]C[3] и M[3]C, where symbol M refers to atoms of metallic elements Fe, Cr, and Ni) is possible in equilibrium conditions in given materials. The irradiation of steels 12X18H10T and 20X13 with a high-intensity pulsed electron beam of the submillisecond duration of exposure is carried out. It is shown that the electron-beam processing of steel in the melting mode and the subsequent rapid crystallization is accompanied by a significant transformation of the surface layer structure, consisting in complete dissolution of original carbide phase particles; in formation of dendritic crystallization cells of submicron sizes; in occurrence of martensitic [gamma]->[alpha] and [gamma]->[epsilon] transformation; in re-allocation of nanosized particles of carbide and intermetallic phases

Comparative studies of the irradiation effects of ZrWn coating with helium and krypton ions at low and high temperatures

The effect of irradiation with low-energy helium and krypton ions on the surface structure, hardness, and corrosion resistance of ZrWN coatings was studied. Magnetron sputtering was used to form ZrWN coatings on structural steel substrates. Irradiation was carried out at room temperature and 600 °C. It was shown that the structure and properties of coatings degrade under irradiation with helium and krypton ions. Irradiation temperature affects the degree of degradation – with increasing temperature, corrosion resistance and strength characteristics of the coating decrease

Distribution of local deformations on the near-surface layers and scale effects of low-alloy steel specimens

This paper presents data on the study of the evolution of local microdisplacements on the surface of specimens made of ferritic-austenitic steel during compressive deformation. The experiment was performed on the test machine “Universal Testing Machine 4500” using a digital optical system Vic-3D for deformation of the specimen surface. It was found that the transition from stage III to stage IV is accompanied by an increase in the area of the region with high values of microregion displacements in the center of the specimen, which corresponds to the parabolic stage

Binary phase diagrams based on elements VIIIA and IB periods of the D. I. Mendeleev's table and features of crystallographic parameters

The data obtained as a result of the analysis of crystallogeometric parameters and the structure of state diagrams of binary systems from elements VIIIA and IB periods of the D. I. Mendeleev's table are presented. It is shown that the classification of the evolution of phase diagrams of binary systems by types, proposed by T. A. Lebedev, correlates with features of concentration dependences of the deviation of atomic volumes in solid solutions from Zen law

Effect of irradiation with low-energy alpha particles on the structural-phase state of coatings of triple nitride systems based on titanium and vanadium on steel

The paper presents the results of studies of the effect of alpha-particle irradiation on the structural-phase composition of nitride coatings CrTiN, MoTiN and NbTiN on the surface of a steel substrate. The coatings were formed by vacuum-arc condensation in a gas medium with N2 using ion bombardment with the use of Ti, Cr, and Mo cathodes. In addition, coatings in a N2 gas medium on a steel substrate were produced by magnetron sputtering from Ti and Nb metals. Experimental data and the analysis of state diagrams of ternary systems of nitrides based on titanium and vanadium with transition metals of IVA-VIA groups have allowed deriving criteria for choosing materials for production of nitride coatings with a fairly high radiation stability

The application of an assisting gas plasma generator for low-temperature magnetron sputtering of Ti-C-Mo-S antifriction coatings on titanium alloys

The positive effect of assisting influence of high-density gas plasma formed by an independent plasma generator PINK on mechanical and tribological characteristics of Ti-C-Mo-S magnetron coating on titanium alloys at lowered to 350°С temperature of coating regardless of alloy structural condition was revealed by methods of calotest, nanorecognition, scratch testing and frictional material tests. The coating formed by means of a combined magnetron plasma method reduces titanium alloys friction coefficient in multiple times and increases wear resistance by two orders of magnitude. At the same time the mechanical properties of ultra-fine-grained titanium alloys obtained by nanostructuring do not deteriorate

The interaction potential of an open nanotube and its permeability: molecular dynamics simulation

The integration of the modified LJ-potential allowed revealing the universal effect of the open carbon tube on the molecular objects moving within or proximate to the tube. There has been established that there are modes of the molecule motion without the energy exchange with the atoms of the carbon framing, under which the moving molecules are subjected to the considerable activation in the tube. The potential holes being the sorption zones in fact are localized

Steel surface TiCrN, TiMoNcoatings structural phase state change features after low-energy alpha particles irradiation

The low-energy alpha particles irradiation impact on structural phase composition and 321S31 steel surface TiCrN and TiMoN coatings morphology have been summarized. The samples irradiation has been carried out in the DTs-60 (the Dubna cyclotron) heavy-ion accelerator by the{4}He{+2} low-energy ions (40 keV) into a 1.0•10{17} ion/cm{2} fluence. It has been established thatthe 321S31 steel alpha particles implantation having energy of 40 keV results in the austenite initial γ-structurepartial transfer, stimulated by the irradiation, to the martensiteα-structure. The low-energy alpha particles irradiation within the fluencies range from 10{16} to 10{17} ion/cm{2} for the TiCrN and TiMoN coatings formed by the ionic bombardment condensation method doesn't result in the phase transfers with a coating crystal lattice type change

Crystallographic parameters of compounds and solid solutions in binary systems Cu-Pt and Ga-Pt

The study establishes that the packing index in compounds of the system Cu-Pt is close to the value 0.74 against a slight deviation from the Zen law of atomic volumes. The compounds in the system Ga-Pt have the highest values of the packing index in the range of the equiatomic composition, which greatly exceed ψ for close-packed structures based on FCC and HCP lattices for compounds made of the same kind of atoms. A correlation between singular points on the phase diagram of the system Ga-Pt and high values of the packing index in compounds is established

Zen law and features of liquidus-solidus curves in binary state diagrams based on elements VIIIA and IB of the periodic table

The paper presents the analysis of binary state diagrams based on elements VIIIA and IB of the periodic table and crystal geometry parameters of solid solutions and intermetallic compositions. The analysis shows an explicit correlation between the type of the evolution of phase diagrams classified by Lebedev depending on the nature of atomic volume deviations observed in solid solutions and intermetallic compounds from Zen law