Advanced Materials Research Vol. 1013

Abstract: A conceptual model consisting of diagrams, text and terminology dictionary, made in a formalized way and representations of functions, each of which reflects the real state of the long-running metal at all stages of the life cycle. Based on the developed conceptual model, analysis of the results of electron microscopic studies measuring the acoustic characteristics and determination of physical and mechanical properties of the complex criterion limiting state long working metal technical devices hazardous production facilities.

Abstract: Using transmission electron microscopy methods the layer by layer analysis of the bulk hardened superior quality rails is carried out and the quantitative parameters of structure, phase state and defect substructure gradients are established. It is shown that the interface boundaries globular cementite particles-matrix are the possible places of microcracks initiation.

Abstract: Arrangement of internal stresses in deformed austenitic steel is studied. The internal stresses are determined using parameters of bending extinction contours observing on electron microscope images of steel.

Abstract: General trends and other aspects of the deformational behavior, localization of plastic deformation on the macroscale level, and fracture of submicrocrystalline and coarse-grained titanium with different interstitial impurity levels are established. It is shown that for the submicrocrystalline structure as well as for the coarse-grained structure, strengthening by interstitial impurities decreases with increase of the deformation temperature. Experimental data are presented which indicate that in the development of grain-boundary sliding in submicrocrystalline titanium with simultaneous onset of recrystallization, a high degree of plastic deformation is reached before fracture occurs, where the deformational behavior and localization of plastic deformation on the macroscale level are analogous to the same processes under superplastic flow.

Abstract: The paper presents X-ray diffraction and scanning electron microscope analyses, and durometer measurements used to investigate the structural properties and phase composition of nitride layers of type 20Kh13 mild steel. A method of nitriding by low-pressure arc discharge was applied along with the combined surface treatment including ultrasonic finishing and nitriding. It was shown that within the close-to-critical temperature range starting from 200oС, the nitride layers was formed on the surface of type 20Kh13 mild steel. The ultrasonic pre-treatment shown its effect on the steel nitriding that increased the amount of nitride phases and the value of microharness on the steel surface.

Abstract: The paper reviews the results of investigations of the surface layer structure and properties of type 35-L steel and commercially pure titanium modified by plasma flows (arc plasma torch with the powder blown into an arc), electro-explosive alloying of titanium specimens, and high energy electron-beam treatment performed on the vacuum electron-beam plant SOLO. It is shown that the surface treatments under review have lead to a multilayer and multi-phase structure formed by crystalline particles of sub-microsized and nanosized range, mechanical (microhardness) and tribological (wear resistance) properties of which exceed manifold that of the substrate material.

Abstract: Using optical and electron microscopy and also X-ray diffraction laws were investigated of carbide phases particles redistribution in the roll near-surface layers (at surface and at distance of 0.5 mm, 2 mm from surface) made of 30CrMnSiА steel during hot deformation. There are located at borders and joints of isotropic and anisotropic fragments and also inside these fragments. Shows the dependence of carbide phases volume fraction (cementite and special carbides). There are located in different structural components and different locations of the roll surface layer. Shows a relationship carbides with dislocation substructure. Shows a gradient character in the laws of carbide phases distribution as they approach the roll surface.

Abstract: Method of estimation of current amplitude (~10 kA) pulses constructed by powerful current pulse generator is suggested. It bases on the solution of differential equation current and voltage change on capacitor. The final formula consists of maximum value of capacitor charge, maximum negative voltage value, pulse duration and capacitor value.

Abstract: The effect of different cutting (mechanical heat treatment) on the structural-phase condition and the internal stress field in the surface layers of the product is considered in the article. The regularities of acoustic characteristics depending on the parameters of the structure and stress for the development of nondestructive method for assessing the quality of the surface layer are identified

Abstract: In the given work, the investigations have been directed to the creation of porous composite materials with MgO and B₄C ceramic filler. The laboratory technology of obtaining rods from the given materials has been developed. The experimental part of this work was carried out on ballistic set-ups with shaft-reactive and electrochemical technologies of throwing with the use of high-energy plastisol fuels with nanosize metallic fillers. Mathematical modeling of the behavior of materials under conditions of high-speed interaction was carried out in the framework of a porous elastoplastic medium according to different destruction mechanisms.