Optimization of electrical contact properties and arc erosion resistance of Mo–W–Cu ternary contact materials prepared via hydrogen sintering under DC arc conditions

Early detection of NOx spikes in ferroalloy electric arc furnace plants

Comprehensive review of biomass applications in DRI-based electric arc furnace steelmaking

Unveiling the energy transfer paradox in electric arc furnace long arcs: a thermal-flow field synergy perspective

A novel process for preparing Si-Fe-Al-Ca alloy from coal gasification coarse slag by using electric arc furnace

Selective Extraction and Coprecipitation Strategy for Effective Removal of ¹³⁷ Cs and Heavy Metals from Radioactive Electric Arc Furnace Dust Leachates

Effect of External Air Gap Length on Electric Arc Behavior in Multi Chamber Arresters under Different Lightning Polarities

This study investigates the influence of arc discharge current on the morphological, electrical, and plasma characteristics of carbon nanoparticles synthesized via submerged plasma arc discharge in deionized water. Arc currents of 40 A, 70 A, and 100 A were applied to graphite electrodes, and the resulting nanostructures were characterized using transmission electron microscopy (TEM), current-voltage (I–V) electrical measurements, and ionization energy analysis derived from time-resolved arc current behavior. The findings demonstrate that increasing the arc current significantly alters the morphology of the carbon products, transitioning from predominantly spherical carbon nano-onions (CNOs) at 40 A to multi-walled carbon nanotubes (MWCNTs) at 100 A. Concurrently, I–V characterization reveals an increasing trend in electrical resistance, rising from ~20 kΩ at 40 A to ~90 kΩ at 100 A, suggesting a strong correlation between nanostructure geometry and macroscopic conductivity. Ionization energy distributions derived from arc current dynamics further reveal a transition from continuous energy profiles at 40 A to highly discrete peaks at 100 A, indicating a shift in plasma species and energy transfer mechanisms. These discrete ionization profiles at higher currents are proposed to facilitate anisotropic carbon growth, favoring CNT formation through directed energy delivery and ion-assisted crystallization. This work elucidates the coupled roles of arc current, plasma behavior, and nanoparticle morphology in determining the structure and electrical properties of carbon nanomaterials synthesized via arc discharge.

The application of hybrid technologies allows improving welding productivity by reducing welding material consumption, edge preparation time, heat input, and, consequently, the probability of crack formation. Welding of dissimilar metal combinations (copper – aluminium) is best performed using pulsed processes at temperatures below the melting point. A high-voltage capacitor welding process has been developed at Don State Technical University. This process combines several stages: electroerosive cleaning during the burning of an electric arc between the weld surfaces, the convergence of the parts, and the splashing of molten metal from the weld zone followed by plastic deformation of the juvenile surfaces. Thermal force impact on the welded parts is implemented by connecting sequentially the upset mechanism together with the welded parts into the discharge circuit of a pulse current generator, with the total duration not exceeding 200 μs. The discharge circuit parameters (inductive and active resistance, capacitance) were selected to enable welding by means of a damped sinusoidal discharge and to ensure the necessary process energy parameters (capacitor bank capacitance and voltage) and the strength characteristics of the welded joint. A temperature measurement technique based on recording spectral radiation during arcing was developed, which allows evaluating the thermal component of the welding process. Following pressures were calculated: magnetic pressure, pressure generated by the upset mechanism, pressure of molten metal vapor, and impact pressure. Methods for recording the temperature and pressure in the welded parts during impact and plastic deformation were developed. The obtained results allow evaluating the feasibility of joining parts of different thicknesses and heterogeneous combinations of non-ferrous metals during the development of the welding process.

In recent years, 3D printing technology has become increasingly widespread and continues to gain popularity. Undoubtedly, we can expect to see the widespread adoption of additive manufacturing techniques in the future, but the practical application of 3D printing is already available to everyone today. The authors of this article consider possible options for implementing a modular hotend mounting system for a 3D printer. They consider possible options and advantages compared to traditional hotend mountings that exist today. They test such a mounting system on an experimental stand created with the mechanics of a 3D printer. During continuous operation of a 3D printer, it is often necessary to clean the hot end, which means constantly stopping the printer for a certain amount of time. It may also be necessary to replace the nozzle diameter in the extruder itself. Sometimes it is also necessary to quickly change different types of plastic. According to the authors, such a modular mount can speed up the hotend maintenance process. In the future, aluminum-based options are proposed as the material for manufacturing the body of such a mount. This material has sufficient strength and low weight, which is important for printer mechanics. Based on this modular mounting system, the authors consider the possibility of connecting other working devices to the printer's mechanics. Among them, it is proposed to develop a working body based on a plasmatron. For this plasmatron option, it is proposed to build it according to the plasma jet scheme. With this design, an electric arc ignites the plasma inside the plasma torch, and a stable plasma beam emerges through a thin nozzle. The printer's mechanics will allow for precise and even cutting of the material, which, according to the authors, will enable the cutting of metals and their alloys of small thickness. In the future, such application of a plasma torch on the mechanics of a 3D printer will still require experimental testing.

Aluminium matrix composites (AMCs) have gained significant attention as advanced lightweight materials for structural and functional applications due to their superior strength-to-weight ratio, wear resistance, and thermal stability compared with monolithic aluminium alloys. Conventional ceramic reinforcements such as SiC and Al₂O₃, however, are associated with high cost, energy-intensive processing, and limited sustainability, particularly in developing economies. In response, agro-industrial and industrial waste materials—including rice husk ash, palm kernel shell ash, coconut shell ash, bamboo leaf ash, fly ash, waste glass, red mud, and electric arc furnace dust—have emerged as promising low-cost and environmentally sustainable reinforcement alternatives. This review critically synthesizes recent developments (2018–2025) in waste-reinforced AMCs, covering reinforcement production, processing routes, microstructural evolution, strengthening mechanisms, and performance outcomes. Emphasis is placed on mechanical, tribological, physical, corrosion, and sustainability-related properties, with performance trends systematically benchmarked against both unreinforced aluminium alloys and conventionally reinforced AMCs. Reported results indicate that optimized waste-derived reinforcements can deliver 15–45% improvements in tensile strength and 25–65% reductions in wear rate while preserving aluminium’s low-density advantage. Beyond performance assessment, this work uniquely identifies critical research gaps limiting industrial adoption, including the lack of standardized benchmarking frameworks, insufficient long-term durability and fatigue data, incomplete understanding of particle–matrix interface mechanics, variability in waste composition, and the scarcity of quantitative life cycle and techno-economic analyses. Future research directions are proposed, highlighting the need for standardized preprocessing protocols, advanced interface characterization, predictive modelling, and data-driven materials design. Overall, this review establishes waste-reinforced AMCs as viable, sustainable alternatives to conventional composites and provides a structured roadmap for their transition from laboratory-scale studies to reliable engineering applications aligned with circular economy principles. Keywords: Aluminium matrix composites, Agro-industrial wastes, Industrial waste, Modelling, Mechanical performance, Sustainability, Wear resistance

Aim: To examine the specific characteristics of the industrial microclimate in steelmaking shops, analyse the heat balance of thermal units, and justify engineering solutions aimed at improving microclimatic conditions using an electric arc furnace as an example. Methodology: An analysis of existing scientific publications on occupational safety in metallurgy, occupational hy-giene, and heat engineering has been carried out. Calculations were performed to assess the thermal balance of the steelmaking furnace and the aspiration system for gas and dust extraction. Results: It has been established that in modern steelmaking shops the air temperature at workplaces during the warm season often exceeds the maximum permissible levels by 2–14 °C, reaching 31–35 °C, with reduced humidity of 33–55 % and significant thermal radiation of up to 8000 W/m². During the cold season, the temperature in certain open areas de-creases to 3–18 °C. It has been determined that 70–75 % of the total heat emission in a steelmaking shop is generated by in-frared radiation from molten metal and heated surfaces, which leads to worker overheating. The heat balance of an electric steelmaking furnace is characterised by substantial losses: only about 50–60 % of the supplied energy is retained as the heat of the produced steel, while the remainder is dissipated through slag, cooling water, refractory lining and exhaust gases. The latter carry away up to 10 % of the energy and reach temperatures of approximately 1500 °C, with dust concentrations of 1.5–8 g/m³. A comparison of ventilation schemes has been performed. Conventional shop aeration does not ensure adequate removal of excess heat or harmful emissions. A combined aspiration system for the electric furnace has been proposed, inte-grating a local hood above the furnace and an extraction duct in the furnace roof. The optimal parameters of this system have been calculated: a gas velocity in the duct of approximately 6 m/s, an exhaust gas volume of around 24 000 m³/h, and a pipeline diameter of 0.5–0.55 m. Scientific novelty: For the first time in the context of a steelmaking shop, the application of a combined aspiration method with an adjustable mobile duct has been substantiated. This solution enables effective capture of hot gases and dust while maintaining pressure beneath the furnace roof close to the regulatory level. Practical significance: The implementation of the proposed ventilation system in a steelmaking shop will reduce the air temperature in the working area, as well as dust and gas pollutant concentrations, to regulatory levels, thereby improving working conditions and reducing occupational risks for personnel.

ABSTRACT Combined blowing in an electric arc furnace (EAF) agitates the melt, causing variable damage to the bottom and wall refractory linings. A numerical simulation is used to investigate the scouring and erosion intensity of the melts on the refractory lining and bottom during combined blowing. The research results indicate that there are four relatively severe erosion areas on the refractory materials of the furnace wall during the combined blowing process, primarily distributed near the impact pits formed by the oxygen lance jet and the area opposite the oxygen lance. The maximum wall shear stress in these areas is 6.477 Pa. There are two relatively severe erosion areas on the refractory materials of the furnace bottom, mainly concentrated near the bottom blowing openings, with a maximum wall shear stress of 31.930 Pa. A novel physical experiment qualitatively verifies the numerical simulations, with experimental and simulated data in good agreement. The study quantifies scouring and erosion intensities of refractory materials during EAF smelting, identifies key monitoring areas, and informs maintenance strategies. It also provides a basis for future dynamic slag-induced refractory erosion experiments and for safety monitoring and early warning of remaining refractory material thickness in the EAF.

Oxidation Protection of Al and Cu/Al Coatings Deposited by Wire Arc Spraying for Graphite in Electric Arc Furnaces

Environmental issues of formation and utilization of electric arc furnace dust

Abstract Arc discharges in transformer oil under internal short-circuit conditions decompose the insulating oil, producing gases that accumulate in the sealed, oil-filled tank, thereby raising the internal pressure and potentially triggering explosion accidents. In recent years, multiple incidents of large oil-immersed power transformers experiencing internal short-circuit-induced explosions have been reported, highlighting the urgent need for accurate pressure calculations under arc conditions to support explosion-proof design. The pressure rise inside the tank involves coupled interactions among gas, liquid, and solid phases. Although previous studies have performed gas–liquid–solid coupled simulations, they did not account for the segmented characteristics of the pressure waveform and failed to elucidate the underlying coupling mechanism. This study investigates the formation mechanism of segmented pressure waveforms resulting from arc discharges in transformer oil within sealed tanks. By analyzing the distinct generation mechanisms across different pressure stages, the gas–liquid–solid coupling mechanism of the pressure rise is clarified, and a segmented coupling calculation method is proposed. The computed waveforms achieve over 90% similarity with experimental results. This work provides both a practical tool for calculating arc-induced pressure inside transformers and theoretical support for explosion-proof design.

Abstract The demand for affordable, compact, and reusable sensors as well as probes is increasing day by day, which can significantly improve the quality of life. Thermally-tailored Optical Fiber Lens have a place in this niche area, representing the next generation of fiber-optic sensors, shifting the paradigm of sensing. This article provides a comprehensive overview of thermally-tailored optical fiber lens, which can be achieved by heating the facet of the optical fiber. Across the reported works, the terminology for these structures is multiple, including fiber ball lenses, ball resonators, spherical tips, and microspheres. In this work, the theory of thermally-tailored optical fiber lens in applications such as light coupling, sensing based on interferometric and whispering gallery mode, as well as their respective advances, are discussed in detail. The fabrication techniques to achieve such structures have evolved over the time from flame torch, arc discharge, filament heating to CO2 laser-based solutions. These techniques are compared and contrasted, providing insight into choosing the right technique according to the need of application.

A Mathematical Model for Metal–Slag Reactions in the Electric Arc Furnace in Stainless Steelmaking

An overview of the issues of energy efficiency of electric arc plasma torches of a linear circuit for coating is presented. Plasma torches with a self-aligning arc length, shorter (with a ledge) and longer self-aligning (with interelectrode inserts) arc lengths are considered. The relevance of studying and schematics of plasma torches with multi-water injection of powder into the plasma torch channel and plasma jet, the tendency of combining multi-arc plasma torches from linear modules, allowing to increase the power of the plasma torch and reduce the erosion of cathodes, is shown. The problematic issue of developing a methodology for selecting a plasma torch circuit and design is presented.

This study introduces a composite method that integrates a diamond-coated tubular grinding electrode with short electric arc machining (SEAM) for GH4099. Mechanical micro-grinding and arc erosion act concurrently within the inter-electrode gap, enabling an in situ "erode-dress" coupling in which the grinding action levels nascent craters and promotes debris evacuation while SEAM supplies localized thermal-electrical energy for removal. A design-of-experiment scheme probes discharge and grinding factors, and performance is evaluated by material removal behavior, electrode wear, and surface integrity. Within a robust window (12-24 V; 500-2000 r/min), the composite process sustains stable discharges without catastrophic melting at 24 V and yields dense, uniform textures. Representative surfaces show controllable areal roughness (Sa ≈ 14-27 µm across 80#-600#), reflecting a practical finishing-efficiency trade-off. Multi-scale characterization (3D topography, cross-sectional metallography, SEM) evidences suppression of recast steps, macro-protrusions, and irregular pits, with more evenly distributed, shallower grinding traces compared to those with single-mode SEAM. The comparative analyses clarify discharge stabilization and recast-layer mitigation mechanisms, establishing a feasible pathway to high-quality, high-efficiency composite SEAM of GH4099 without resorting to overly aggressive electrical conditions.