The global demand for oil and gas products has caused noticeable qualitative and quantitative changes in the applied technological processes of manufacturing parts and equipment for the extraction and transportation of oil products. Kazakhstan is the largest oil-producing country in the world, therefore, the development of advanced technology for the production of oil and gas equipment can stimulate industrial and economic growth. Traditional technologies for hardening critical parts of Wedge-Shaped Columns (WSC) are energy-consuming and labor-consuming, although they are used in many industrial enterprises. For scientific research on chemical-thermal hardening of a low-carbon alloyed die made of steel 20X, GOST 33260-2015 (207 Steel), wedge column piping, an experimental installation for electrolytic-plasma hardening has been developed. Experimental studies of plasma electrolyte hardening were carried out in various processing modes. The dependence of the current-voltage characteristic of the high-speed heating of the part on the temperature of the ionized electrolyte plasma is described. The processes of heat transfer, heating, and quenching in the electrolyte are described by a mathematical model, a regression formula is derived. The main parameters of the electrolytic-plasma hardening are determined, and the optimal processing modes are derived. Raster elemental analysis indicates the surface modification of the hardened layer of low-carbon alloy steel with carbon. The method of electrolytic-plasma hardening allows locally hardening of the mating working surfaces of the PCC die. Investigated the results of changes in the microstructure, an increase in hardness relative to the initial state. The article is financially supported by the "Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan" within the framework of the grant project IRN AR09058518 "Increasing the wear resistance of materials in the engineering industry by electrolyte-plasma modification". Copyright © 2022 Praise Worthy Prize - All rights reserved.

This study aimed to develop an alternative surface hardening technique for low-carbon steel alloy type 20Ch using plasma electrolytic oxidation (PEO). The surface hardening of 20Ch alloy steel samples was achieved through PEO in a Na₂CO₃ electrolyte solution. Optimal processing parameters were determined experimentally by measuring voltage and applied current. Quenching was performed in the electrolyte stream, and plasma was ionised through excitation. A mathematical model based on thermal conductivity equations and regression analysis was developed to relate the key parameters of the hardening process. The results from both the experimental and mathematical models demonstrated that PEO significantly reduces hardening time compared to traditional methods. The microstructural images revealed the transformation of the coarse-grained pearlite–ferrite structure into quenched martensite. Vickers microhardness tests indicated a substantial increase in surface hardness after PEO treatment, compared to the untreated samples. The major advantages of PEO include lower energy consumption, high quenching rates, and the ability to perform localised surface treatments. These benefits contribute to overall cost reduction, making PEO a promising surface hardening method for various industrial applications.

The development of new fields in the oil and gas industry of Kazakhstan, the exploitation of fields with hard-to-recover reserves, and the exclusion of harmful environmental impacts require the study of new advanced technologies in the manufacture of valves. Hardening of the throttle tip in the factory from low-carbon corrosion steel is provided traditionally: carburizing in a solid carburetor, followed by hardening and normalization in an electric furnace. However, this process is accompanied by high heat losses, long time spent on heating and cooling the furnace to the required temperature, and high-energy consumption-power costs are 60-100 kW/h. The carbon penetration rate is low, and for depths of 1-1.5 mm, it becomes necessary to heat the workpiece in a carburetor for 8-10 hours at a certain temperature, followed by hardening and normalization. The technological process of traditional hardening by cementation, followed by hardening and normalization, is accompanied by the appearance of various defects. The most common defects include the formation of microcracks, warpage, scale, and peeling of the metal, as well as high labor intensity and energy intensity. A technology has been developed for hardening the tip on an electrolytic-plasma modification installation, which includes heating the part to 910-9600C and quenching in an electrolyte flow at 330-3600C, characterized in that the part is heated by electrolyte plasma, the temperature of which exceeds 6000 K. Analytically and experimentally it was determined that heating with electrolyte plasma for quenching is achieved within 4 seconds and quenching in the electrolyte flow is achieved within 8 seconds. With cyclic electrolytic plasma hardening at the 10th cycle with 40 seconds of total processing, optimal hardening rates are achieved. An electron microscopic study of the hardened structure indicates a phase transformation and the formation of hardening martensite with a carbide network, which strengthens the steel. The tribological properties and friction coefficient of the surface layers formed during electrolytic-plasma hardening indicate an increase in the wear intensity by more than two times.

This study investigates the microplasma deposition of molten tantalum (Ta) onto a rotating Grade 5 Ti Extra-Low Interstitial (ELI) alloy, producing multilayer film coatings with a porous microstructure. Optimal parameters for microplasma spraying Ta were experimentally determined to improve the surface properties of elbow joint implants. The physical and mechanical properties of the Grade 5 Ti ELI substrate and the Ta-based coating were analyzed. Moreover, mathematical modeling was utilized to determine the optimal parameters for the plasma coating process, including key factors such as spray distance, current, and rotational speed, which were systematically applied across three experimental series. A Ta coating thickness of 250 μm was achieved at 35 A current, 410 mm spray distance, and 7 rpm rotation speed under optimized deposition conditions. The results showed a microhardness increase on the Ta-coated surface, peaking above HV1000 with an average of HV742, while the Ti substrate averaged HV325. Additionally, the XRD patterns revealed the presence of metallic Ta alongside Ta oxides, such as Ta₂O and Ta₂O₅, in the Ta coatings.