• TESTING OF AUTOMATICIZED SYSTEM FOR COMPLEX NON-DESTRUCTIVE STUDY OF METALLIC MATERIALS

    pg(s) 273-276

    Presented a program to test the automatized system complex non-destructive testing of structure and physical and mechanical properties of samples and products from metallic materials. The system consists of several modular devices that measure two non-destructive information parameters based on methods with different physical bases (magnetic, acoustic, thermoelectric, etc.). In the work are presented only two modular unit – MULTITEST MC010 for testing ferromagnetic materials, using the methods of measurement of the magnetic noise voltage and magnetoacoustic emission and MULTITEST CD010 for testing of metallic materials with the methods for measuring the speed and the attenuation coefficient of ultrasonic waves in the materials. Have been developed – general methodology of the system for testing / measuring equipment and methods for calibration and metrological instruments in operation of the system in a complex  non-destructive testing. Conclusions are made on the reliability of system measurements when used in complex non-destructive control of metallic materials.

  • ECONOMIC ANALYSIS OF REPLACEMENT OF CONVENTIONAL WELDING TECHNOLOGY WITH UNCONVENTIONAL

    pg(s) 268-272

    The technological and social environment in which we live changes very quickly. Competition grows from time to time, so it is a constant tendency towards product and service providers to achieve a competitive advantage, and thus satisfy the needs of consumers. In order to achieve the above, the organization is often at a crossroads where important decisions are needed, which are most often related to the investment in new equipment or technology. Also, in parallel with the decision to invest in new equipment or technology, a decision is made to retain or upgrade the existing one. In order to make the right decision, often well-known postulates of engineering economies are often used, which include systematic assessment of the economic values of the proposed solutions. In order for economies to be acceptable, solutions must show the existence of a positive relationship between long-term benefits and long-term costs, as well as ensuring the success and survival of companies in the market. In this paper, the economic costeffectiveness of replacing the existing electrolytic welding technology with insoluble electrode in inert gas (TIG), the new FSW welding technology is considered.

  • REDUCING THE ENERGY INTENSITY OF MULTI-PRODUCT MACHINERY PRODUCTION BY IMPROVING THE CORE PRODUCTION INFRASTRUCTURE

    pg(s) 266-267

    Multi-product machinery production forms a machine park of an industrial organization, so the finished products must provide high-quality and economic indicators while using them in productions. The problem of increasing the level of production efficiency is analysed in such organizations depending on the improvement of the basic production infrastructure. The new, quantitative indicators are presented, which help justify the interrelations of material, labor and energy production costs. The necessity of implementation of innovative technological processes at the preproduction phases is justified, which allows to reduce the level of material intensity, labor intensity and energy intensity of production and increase the efficiency of the production organization.

  • QUALITY CONTROL OF MULTI-PASS WELD BY MEANS OF ACOUSTIC EMISSION

    pg(s) 263-265

    The article proposes a method of assessing the quality of multi-pass weld by acoustic emission. The AE method involves the identification of developing defects at the stage of stress changes in the material, as well as in the statically loaded state. In the process of control two independent data collection systems were used, which worked in the process of testing synchronously. The selected method of control of the object has a number of advantages over other methods of NDT.

  • AN INNOVATIVE APPROACH FOR REPAIRING OF CORRODED REINFORCED CONCRETE INDUSTRIAL STRUCTURES IN AGGRESSIVE ENVIRONMENT BY HIGH-TECH HYBRID REINFORCED SPRAYED CONCRETE WITH CAPILLARY CRYSTALLINE ADMIXTURE

    pg(s) 259-262

    Solvay Sodi JSC, Devnya, Bulgaria, is the biggest calcite soda production plant in Europe. It is built in 1974 and it works in three-shift production regime up to present days. The exploitation environment is highly influenced by numerous factors, acting corrosively on main reinforced concrete structures – active atmospheric processes (in continental type moderate climate), sea water born chloride-aerosols, as well chemical attack caused by carbon dioxide and nitric acid, presented in the air in form of evaporation. The most reinforced concrete structures need urgent remedial measures to restore the load-bearing capacity of its components.
    The “light soda” silos are reinforced concrete facilities (cylindrical shells) which repair has to be executed during continuous production process. The options for repair of these structures and restoration of their load bearing ability by specially designed innovative high-tech hybrid reinforced sprayed concrete, containing capillary crystalline admixture, are discussed in the report.
    The in-situ tests and wide-range comparative studies are carried out, covering basic physical and mechanical structural characteristics of the proposed sprayed concrete for wet spraying and another one – based on proportioned dry ready mix.
    The original scientific results concerning strength-deformation properties, phase composition and structure of hardened sprayed concrete, directly related to the durability in aggressive environment, are obtained by X-ray diffraction (XRD), differential thermal analysis (DTA), mercury porosimetry, low temperature gas adsorption (BET-method) and computer X-ray tomography.
    The static and dynamic analysis of the structure is performed using the test results obtained and the fully specified engineering solution has been presented to restore the load-bearing capacity of the structures with a guaranteed service life of at least 50 years.

  • NOVEL TECHNOLOGY OF METAL POWDERS PRODUCTION BY HYDROVACUUM DISPERSION OF MELTS

    pg(s) 236-239

    A novel technology for producing metal powders is presented, the distinctive feature of which are the conditions of forming of powder particles. In particular, under the proposed technology the melt is sucked bottom-up by the vacuum produced by the toroidal vortex of the discharged nucleus of high-pressure water flow in the two-layer cylindrical shell cavity, where it is being dispersed as metallic particles and carried over from the working medium to a special store. The so produced powders have a particular morphology and structure, increased specific surface area and microhardness.

  • QUALITY CONTROL METHODS FOR THE EVALUATION OF QUALITY STABILITY OF REINFORCING BARS

    pg(s) 233-235

    The evaluation of the quality of production process on mechanical properties of reinforcing bars profile 10-32 of steel grade 35GS was performed, obtained in the conditions of the rolling production of JSC “ArcelorMittal Temirtau”. Using a complex quality parameter, the process of rebar production is characterized as stable and controlled.

  • PECULIARITIES OF CHEMICAL-THERMAL TREATMENT OF SEMI-PERMEABLE POWDER METALLURGICAL MATERIALS IN SEMI-PERMEABLE SATURATION MEDIA

    pg(s) 219-221

    The main characteristic of the powder metallurgical materials that distinguishes them from the summer ones is the presence in them of residual porosity. For this reason, the processes of their thermochemical treatment are differ significantly from those occurring at saturation of dense ones. In the present paper the impact of technological processes such as boronizing, chromizing, siliconizing, carburizing, borocarburizing, etc., is monitored on the kinetics of diffusion layer growth in powder materials with a porosity of 5÷35%. The specimens of iron powders NC 100.24 and those doped with 2% Cu were subjected to study. The samples were pressed with an effort of 200 ÷ 800MPa and sintered for 0.5h at 1150°C in dissociated NH3 medium. Thermochemical treatment was conducted at 950°C for 4 hours in semi-permeable saturation media. Graphical dependencies for varying the thickness of diffusion coatings in different thermochemical treatment modes are presented, depending on the porosity of the saturation materials.

  • WELDING OF GRADE 1 TITANIUM BY HOLLOW CATHODE ARC DISCHARGE IN VACUUM

    pg(s) 216-218

    Because of the combination of high specific strength and excellent corrosion resistance in many media, titanium and titanium alloys are used in aerospace engineering, chemical industry, mechanical engineering etc.
    The present work introduces results that demonstrate the effect of the thermal cycle on mechanical properties of Grade 1 Titanium welds, produced by hollow cathode arc discharge in vacuum. Dimensions of the welds were established. The mechanical properties of the welds – hardness and tensile strength – were determined. The influence of the thermal cycle on welds structure was investigated.

  • DEVELOPMENT AND IMPROVEMENT OF TECHNOLOGIES FOR PRODUCING STRUCTURAL MATERIALS WITH ULTRAFINE-GRAINED STRUCTURE BY SEVERE PLASTIC DEFORMATION

    pg(s) 212-215

    Paper presents an overall analytical review of recent achievements in the field of development and improvement of technologies for producing structural materials with ultrafine-grained structure by severe plastic deformation. Main modern methods of obtaining ultrafine-grained structure by severe plastic deformation are described. Special attention to combined process “helical rolling – pressing” is devoted.

  • A PROCESSES CONTROL SIMULATION TOOL

    pg(s) 182-184

    The paper deals with a variable multifunctional simulation tool that enables to design and assemble animated models of various technological processes controlled by externally connected fuzzy logic unit. It enables to verify the correctness of fuzzy controller settings in the future control of real technological processes in practice. This tool represents an effective, innovative, and creative concept important to understanding control approach of technological processes modeling as an insight to behavior of real industrial processes and their control which is based on fuzzy logic. On the base of this animated simulation, real technological processes control can be realized successfully according to producer demands afterwards. Models of technological processes assembled by this simulation tool can be then externally controlled by various control strategies (traditional PID controllers, ON-OFF controllers,PLC controllers, fuzzy logic controllers etc.) via a proper real controller connected to the computer. In the paper, two-conveyor-belt system for product packing is shown. The goal consists in control of synchronization of products and boxes placed on individual conveyor belts in order to pack the product into the box. The main concern here is to improve dynamic performance and control efficiency with the help of assembling an animated model of the controlled technological process and its external control by a fuzzy logic unit.