Publications in 2011

Articles

The problems of restoration medium and high-carbon steels by hardfasing / V.D.Kuznetsov, P.V. Popovich // Przeglad spawalnistwa, 10/2011.– P.4-7

Restoration peculiarities of the medium and high-carbon materials by hardfacing are shown. Testing of the hardfaced compositions martensitic and austenitic types are presented. Advantage of the austenitic compositions for friction wear and strike loading is proved. Careful consideration is given to engineering strength and failure mechanism under conditions of static and cyclic loading. The directions of hardfacing the compositions with martensitic structures without preheating are proposed.

Evaluation of stability of the flashing process in flash-butt welding / Skachkov I. O., Chvertko Ye. P. // Paton Welding Journal. – 2011. – № 3. – Р. 29-31

Procedure was developed for monitoring the process of continuous flash-butt welding. The feasibility of using neural networks for evaluation of stability of the welding process was established.

Method for estimation of welding properties of power sources for arc welding / Shevchenko N. V., Skachkov I. O., Ponomarev V. E. // Paton Welding Journal. – 2011. – № 4. – Р. 43-46

Method for in-process monitoring of welding properties of power sources by their electric papameters using fuzzy logic algorithms was developed. Criteria for estimation of each indicator and an algorithm for obtaining a general estimated and proposed.

Papers presented on conferences, congresses, assembleys

Possibility of Application of Artificial Neural Network for Recognizing of Acoustic-Emission Events / Pirumov А., Chvertko Ye., Por G., Dobjan T. // VII Hungarian NDT Conference and Exhibition, Eger, Hungary, 2011

Study of possibility of artificial neural network use for recognizing of sources of acoustic-emission events was provided. Informative process parameters were determined. Two types of sources were studied: Hsu-Nielsen and impact with metal bullet. LVQ neural network was used for recognizing. It was identified that quality monitoring technology with use of neural networks allows to detect acoustic-emission events with reasonable accuracy.

New Powder Materials and Processes of Joining Nickel-Based Super-Alloys and Metalloceramics With Nano-Srucured Inerlayers / V. Kvasnitskiy, I. Smyrnov, Ye. Chvertko // 64th Annual Assembly of the International Institute of Welding and International Conference Global trends in Joining, Cutting and Surfacing Technology, Section SG-RES, Chennai, India, 2011

New multi-component coatings have different powder combinations (systems of α–β–γ–δ components) as their basis. α-component includes alloys, oxides, carbides (Ni–Al, Ni–Cr, Al2O3, ZrO2, etc). β-component may include Mо, Al, Cr, Ti. γ-component includes complex oxides – nano-particles of amorphous silicon dioxide and its derivatives with titanium and aluminum. δ-component includes nano-films or local nano-structures obtained with ion-plasma deposition on the surface of powder particles. The process of powder blends production and formation of complex joints with pre-defined stoichiometry including nano-particles consists of several stages.
It was proposed to improve operating characteristics of joints by modificated surface nanostructured microlayers with pre-defined phase and chemical composition. Forming of nanostructured microlayers is obtained by means of surface treatment of components to be joined with high-current low-energy electron beam. Such treatment allows to alloy thin surface layers with different chemical elements, provides forming of high-energy microstructure, which is close to nanostructure (size of phase components and grains is below 0,1 µm) with the dislocation density raised on a few times.

Influence of surfaces modification with using of the concentrated bunches of energy on the forming of joints in solid phase / V.F. Kvasnytskyy, V.V. Kvasnytskyi, N.N. Koval, Yu.F. Ivanov, D.P. Rusalskyi, I.A. Soloduhin,
A.D. Teresov // The 9th International Conference on the Interaction of Radiation with Solids (IRS-2011), Minsk, Republic of Belarus, September 20-22, 2011: Proceedings. – Minsk, 2011

Influence of surfaces modification with using of high-current low-energy electronic bunches (HLEB) on the topography of surface, structure and properties of surface layer, their influence on a forming of joints steel, which related to the different structural classes of heatproof alloys at the diffusion welding (DW) was researched.
It is set that the energy of bunch 20...25 J/sm2 at 5 impulses by duration of 100 μs is the optimum mode of surfaces treatment of 10895, 12Х18Н10Т steels and ЧС88У-ВИ alloy. In the modified layer there is the considerable grain refinement and rising dislocation density up to (2...5)•1011 sm-2.
Micro hardness of the modified layer of 10895 steel is increased by 74%, 12Х18Н10Т steel – by 12 %, and of ЧС88У-ВИ alloy is decreased by 20 %. Subgrain structure of investigational metals after modification is characterized by the presence of high-dispersed phase.
The interaction of both modified surfaces of steels is most actively. While volume stake of overall grains in a joint is almost on an order more by comparison to modification only of surface 12Х18Н10Т and is almost in 3 times more by comparison to modification of surface 10896, even without the account of high-dispersed grains. If is one surface modified only, this must be a surface of α-iron.
At DW of alloy ЧС88У-ВИ the most volume stake of recrystallized grains (45 %) is observed for connection of the modified and unmodified surfaces.
Positive influence of surface modification of dispersed-hardening nickel alloy is caused by both the effect of modification (high dispersion of structure, etc.) and forming high level of tensions in the contact of the modified (hard-tempered) layer and alloy with surplus phases that facilitates development of flowages in the area of contact.
It is set that the best terms for a forming of joints of high-temperature alloys on the basis of nickel are provided at welding of the modified and unmodified surfaces.

Prospects of the application of radiation- fascicular technologies for brazing materials / V.V. Kvasnytskyi, V.D. Kuznecov, V.F. Kvasnytskyy, N.N. Koval, Yu.F. Ivanov, D.P. Rusalskyi, I.A. Soloduhin, A.D. Teresov // The 9th International Conference on the Interaction of Radiation with Solids (IRS-2011), Minsk, Republic of Belarus, September 20-22, 2011: Proceedings. – Minsk, 2011

The influence of alloying surfaces of high-temperature nickel alloys with the application of radiation-fascicular technologies, high-current low-energy electronic beams (HLEB) and the formation of joints with high-temperature brazing with pressure in the vacuum was researched.
The effect of alloying ЧС 88У-ВИ and Inconel 718 with elements which lower the temperature of melting (Zr, Hf, Nb) on the surface topography, structure and properties of surface layer, allocation of elements was studied.
It was established that at thickness of evaporation layer in 1 mcm and density of energy of the beam in 15...20 J/cm2 in reached necessary concentration of element-depressant, while the content of this element in modified layer almost don’t depends on the brand of high-temperature nickel alloy, and the number of melted metal is regulating with thickness of evaporation layer and with data processing mode. Fine-dispersed carbides come to light in fire-polished layer of near-surface area of ЧС 88У-ВИ alloy. Distributing of alloying elements on the surface of the alloyed layer is even.
Joints, with alloying zirconium and hafnium of one of the connected surfaces of ЧС 88У-ВИ alloy or both, are researched. Brazing was conducted with a thermocycling. It is set that adjusting of pressure of compression influences on a structure and properties of joints insignificant, while a superficial layer is played a role of not only solder but also instrumental in development of flowages in the area of joint intensifying the processes of volume interaction.
Treatment of joints surfaces with using of radiation-fascicular technologies is effective way for upgrading and simplification the technology of a high temperature vacuum brazing with pressure.

Technology of Flash-Butt Welding of Reinforcement Bars in Construction of Structures of Monolithic Reinforced Concrete (AWST-11/104) / Ye. Chvertko, P. Chvertko, I. Skachkov // International Congress on Advances in Welding Science and Technology for Construction, Energy and Transportation Systems, Antalya, Turkey, 24-25 October 2011, P. 293-298

The application of flash-butt welding of reinforcement bars in civil engineering under site and semi-stationary conditions in construction of monolithic reinforced concrete structures is considered. This method is characterized by a high stability of characteristics of quality of concrete reinforcement being welded and absence of auxiliary consumables. The main technological parameters of the process were determined, basic technologies were developed, providing the increase in service life of reinforced concrete structures, improvement of their reliability and guarantee of high service life.
The main reasons of formation of defects in welded joints were determined. The on-line monitoring system based on neuron networks was developed for evaluation of process deviations, the feasibility of its application was established.

Ni-Basis Superlegierungen im Turbomaschinenbau und deren Besonderheiten bei der schweisstechnischen Bearbeitung / N. Arjakine, S. Piegert, O. Slyvynskyy // 14 Sommerkurs Werkstoffe und Fuegen am Institut fuer Werkstoff- und Fuegetechnik, Magdeburgh, 23-24.09.2011, P. 71-76