Induction Furnace Research Articles

FEATURES OF THE FORMATION OF THE PHASE COMPOSITION AND PROPERTIES OF HIGH ALLOY STEEL 03Х17Н3Г9МБДЮЧ

Purpose. Evaluation of the influence of alloying elements of corrosion-resistant steel 03Х17Н3Г9МБДЮч on the phase composition and indicators of high-temperature corrosion. Research methods. In order to check the effect of the chemical composition on the structure of steel 03Х17Н3Г9МБДЮч, laboratory steels were made. The production of these steels was carried out in an induction furnace with a main lining with a capacity of 50 kg. The resulting castings were forged into blanks 40 ´ 80 ´100 mm in size, with subsequent hot rolling into samples 25, 20, and 15 mm thick. Determination of the yield strength of steels was carried out after exposure at a temperature of 850 °С for 10,000 hours. The corrosion resistance of the test samples was determined by the gravimetric method after the samples were completely immersed in molten magnesium. Results. The choice of the main alloying elements was justified and their influence on durability in the aggressive environment of the recovery process of spongy titanium production was determined. A thermodynamic calculation of the changed Gibbs energy in the operating temperature range was performed. The required phase ratio of 03Х17Н3Г9МБДЮч steel was considered and selected based on Scheffler de Long and Potak-Sahalevich diagrams. Scientific novelty. The effect of changing the chemical composition of steel 03Х17Н3Г9МБДЮч within technical conditions on the creep limit and durability in the aggressive environment of the recovery process of the production of spongy titanium was determined. Practical value. It is shown that the alloying complex of corrosion-resistant steel is capable of significantly improving the physical, mechanical and technological properties, and expanding the functional application (purpose).

Oxidation behavior of 9Cr-RAFM steel at high temperature

The effect of yttrium on the mechanism of oxidation film formation of the 9Cr reduced activation ferritic/martensitic (9Cr-RAFM) steel was investigated. Four alloys yttrium contents ranging from 0 to 0.065% were melted in a vacuum induction furnace and subjected to continuous isothermal oxidation experiments. The alloys were oxidized in air at 600, 700, 800 and 900 °C for 100 h. Oxidation kinetic curves were obtained and analyzed to study the effect of yttrium on the oxidation resistance of the alloys at high temperatures. The oxide films formed on the alloys were observed and analyzed by X-ray diffractometry, scanning electron microscopy and electron probe X-ray microanalysis. The results indicated that the oxidation weight gain of the samples varied with the yttrium content, with the highest gain observed in the yttrium-free alloy sample, and the least in those containing 0.065% yttrium. Adding yttrium significantly enhanced the high temperature oxidation resistance of 9Cr-RAFM alloy by promoting the formation of a selective Cr2O3 oxide film. The film improved the adhesion of the oxide layer to the base metal, reduced the oxidation rate, and thereby enhanced the high-temperature oxidation resistance of the alloy.

The Development of a High-Efficiency Small Induction Furnace for a Glass Souvenir Production Process Using Multiphysics

A small induction furnace (SIF), which has the important components of copper coils, a ceramic jig, and a graphite crucible, employed for a glass souvenir production process, has been developed as a form of clean technology for multiphysics, consisting of electromagnetics analysis (EA) and thermal analysis (TA). First, two experiments were established to measure parameters for multiphysics results validation and boundary condition settings. Then, the parameters were applied to multiphysics, in which the EA revealed magnetic flux density (B) and ohmic losses, and the TA reported a temperature consistent with the experimental results, confirming the multiphysics credibility. Next, a ferrite flux concentrator was added to the SIF during development. Multiphysics revealed that PC40 ferrite, as a flux concentrator with a suitable design, could increase B by about 159% compared to the conventional SIF at the power of 1000 W. As expected, the B increases alongside the increase in power applied to the coils, and is more densely concentrated in the flux concentrator than in other regions, enhancing the production process efficacy. Lastly, the developed SIF was employed in the actual process and received good feedback from users. The novel research findings are the developed SIF and methodology, exclusively designed for this research and practically employed for a glass souvenir production process.

Modified Higher Order Sliding Control Based Active Harmonic Current Compensator in Induction Furnace Using Emotional Tuned Intelligent Controller

Modified Higher Order Sliding Control Based Active Harmonic Current Compensator in Induction Furnace Using Emotional Tuned Intelligent Controller

A new steelmaking process using red mud as a fluorine-free flux: Promoting phosphorus removal and iron recovery

Bayer red mud, one of the most challenging solid wastes in the aluminum industry, is anticipated to be suitable for large-scale disposal in alignment with the specific requirements of the steelmaking process. This study determined the melting characteristics of various red mud-based fluxes using a high-temperature in-situ analysis system. Furthermore, the feasibility of large-scale application and the potential for substituting CaF2 in the iron and steelmaking process were investigated through a 10-kg induction furnace test and a 160-ton converter industrial test. The results indicate that the hot metal temperature during the pre-phosphorus removal stage ranged from 1254°C to 1430°C. Initial slag formation occurred within 2–4 minutes of oxygen blowing. The average slag basicity was between 1.5 and 2.1. Early dephosphorization and the average phosphorus distribution ratios were 41.4 %-63.4 % and 30, respectively. The mechanism of red mud-based fluxes in the early stage of steelmaking was further elucidated, and the application process was designed. The new process reduces the cost of slag materials, realizes the large-scale disposal of red mud, establishes the connection for the sustainable development of the steel and aluminum industries.

Impact of inclined magnetic field on natural convection in ferrofluid within a semi-circular enclosure with a heated wavy surface

Ferrofluids are liquids that exhibit distinctive magnetic properties when subjected to a magnetic field. Due to their magnetic susceptibility, ferrofluids have recently gained considerable scientific attention. They find tools in different fields, such as electronics, mechanical engineering, and materials science. The inclusion of the semi-circular enclosure inscribed around a heated wavy cylinder provides innovative perspectives essential for engineering applications involving induction furnaces and cancer therapy devices. This paper aims to conduct a computational investigation into the influence of an inclined magnetic field on the free convection within a semi-circular cage stuffed with a ferrofluid featuring an internally undulating surface. It is considered that the interior wavy cylinder was warmed ( T h ) , and the outer semi-circular enclosure is cold ( T c ) . The analyzed system’s governing equations are computed using the Galerkin finite element method (GFEM). The ferrofluid’s flow pattern and thermal transport rate are investigated about relevant non-dimensional values, such as the wave numbers, the number of Hartmann ( 0 ≤ Ha ≤ 20 ) , the number of Rayleigh ( 10 3 ≤ Ra ≤ 10 6 ) , and the volume fraction ( 0.00 ≤ ϕ ≤ 0.09 ) . Evaluating the results involves examining isotherms, analyzing the distribution of flow velocities, and calculating the Nu avg , all while considering variations in fundamental physical parameters. As the Hartmann number ( Ha ) decreases and both the number of Rayleigh ( Ra ) and volume fraction ( ϕ ) rises, the Nu avg of the ferrofluid exhibits an increased. As a result of incorporating ferroparticles, the simulation identifies a maximum value of 35.86 for the Nu avg . It is worth noting that an enhance in Hartmann numbers is associated with an 80% decrease in the velocity stream function. On the other hand, an escalation in ferroparticle values leads to a 9.7% reduction, while elevated Rayleigh numbers result in a 60.8% surge in the stream function. Moreover, the irreversibility stemming from fluid friction, transfer of heat, and the magnetic field can be minimized for ferrofluid fluids ( n = 1 ), by employing the optimal parametric combination.

Decarbonizing rotary kiln–induction furnace based sponge iron production

The direct carbon dioxide (CO2) emissions from the iron and steel sector are nearly 7 % of the global CO2 emissions from energy use. India is the world's second-largest producer of steel and the largest sponge iron producer. India produces one-third of the global sponge iron, mostly from rotary kilns using coal as an energy source, resulting in higher energy and emission intensities than the global average. This study evaluates major options for CO2 abatement in the rotary kiln–induction furnace process for steel production. Based on the mass and energy balances of a typical sponge iron plant, this study evaluates the techno-economic potential of nine major decarbonization measures. The proposed decarbonization measures include improved energy efficiency, improved material efficiency, renewable energy use, and fuel substitution. Marginal abatement and green premium curves are generated by incorporating the dependency of different measures. Depending upon the set of options chosen, carbon abatement is in the range of 55.8 %–99.2 %. It is observed that 11.5 %–20.6 % of decarbonization potential can be achieved without any additional cost to the customer. These findings are insightful for policymakers and industry stakeholders and provide a foundation for designing and implementing a net-zero pathway for the sector.

EFFECT OF CHROMIUM CONTENT ON MECHANICAL PROPERTIES OF NICKEL-FREE AUSTENITIC STAINLESS STEELS

<p>This study investigated the mechanical properties of a series of Fe-Cr-Mn (Mo)-N alloys. The chromium<br />content ranged from 16 to 18 mass%. The test alloys were produced by adding nitrided ferroalloys during<br />melting in an induction furnace. Test specimens of each alloy were prepared for mechanical testing and<br />microstructural observation. Tensile strength (TS) and elongation (EL) were determined. By increasing or<br />decreasing the content of the chromium, it can directly affected on the values of the mechanical properties<br />and the final microstructure. A series of experiments showed that increasing the chromium content by<br />1.46 mass% in the Fe-16Cr-8Mn (Mo)-N alloy led to a decrease in the TS value by 12% and in the EL value by<br />16.1%, while increasing the chromium content by 0.72 mass% in the Fe-16Cr-11Mn (Mo)-N alloy caused a<br />decrease in the TS value by 6.1% and in the EL value by 16%. The chromium content of 16 mass % in the<br />studied alloys was found to provide sufficient strength and a relatively high elongation value. The alloys<br />can also contain a higher mass fraction of chromium, but to obtain a complete austenitic structure it is<br />necessary to increase the content of manganese and nitrogen.</p>

Effect of Gadolinium Content on the Microstructures and Corrosion Properties of Mg-4Zn-3Gd Alloy

Lightweight metallic alloys in the transport sector are the essential choice to reduce carbon monoxide emissions. Magnesium (Mg) can serve this purpose appreciably because it has a low density compared to other metallic metals and a high strength in a small portion of metals. The reason behind this is having very low weight. Notwithstanding the alloys exhibit high susceptibility to corrosion especially galvanic corrosion, which impedes it from its various applications. The corrosion resistance of magnesium alloy depends largely on the surface film whether it can protect well and the corrosion due to galvanic effect between the second phase particles or microstructures and the magnesium matrix. Role of second phase particles eventually improves the corrosion property by enhancing its resistance to corrosion. Mg-4Zn being a promising alloy, 3 wt% Gd has been added further to investigate the corrosion resistant properties of Mg-4Zn-3Gd alloy. After preparing the alloys by casting method in induction furnace followed by homogenization at 410°C, the sample was hot rolled at 400°C. Preparation of the samples has been verified by EDS, XRF and XRD analysis. Corrosion study has been done for 1 hour, 24 hours and 72 hours. Microstructures have been taken for as cast, homogenized, and as rolled condition before corrosion test. The analysis shows a large difference in the grain size and phase distribution. Due to dynamic recrystallization during rolling hardness also shows differences compared to as cast and homogenized sample. The corrosion test is performed by weight loss test, electrochemical measurement, and immersion test. In the results, it has been seen an increase in corrosion rate at the initial stage, however it came to a constant rate after some time. After corrosion test, optical micrographs (OM) and scanning electron microstructures (SEM) images show typical morphology of corroded surface with some micro cracks. The presence of Gd in Mg-4Zn alloy enhanced the corrosion performance when it is done for longer time.

Induction furnace slag as fine and coarse aggregate in quaternary blended self-compacting concrete: A comprehensive study on durability and performance

This research explores the innovative use of Induction Furnace slag Aggregate (IF-slag) as both fine and coarse aggregates in Quaternary Blended Self-Compacting Concrete (QBSCC) mixes, an area that has received limited attention in previous studies. The primary aim is to compare the durability characteristics of QBSCC mixes containing natural aggregate versus those incorporating IF-slag aggregate. A total of 18 SCC mixes were prepared in two groups: one using natural aggregate and the other using IF-slag aggregate. Each group consisted of eight optimized QBSCC mixes alongside a reference SCC mix. The QBSCC mixes were formulated using Ordinary Portland Cement (OPC) with Supplementary Cementitious Materials (SCM) such as Silica Fume (SF), Class F-Fly Ash (FAF), and Ground Granulated Blast Furnace Slag (GGBFS). Previous work by the authors analysed the fresh and mechanical properties of these QBSCC mixes. This study assesses various durability properties, including water absorption, permeable pore volume, absorption coefficient sorptivity, ultrasonic pulse velocity, resistance to chloride ion penetration, electrical resistivity, and thermal conductivity. Experimental findings indicate that SCC prepared with IF-slag exhibited inferior durability performance compared to natural aggregate. However, regardless of aggregate type, QBSCC mixes outperformed the SCC mix containing 100% OPC. Notably, the SCC-47.5 (OPC)/52.5(SCM) QBSCC mix demonstrated significant improvements in durability properties, achieving a reduction of 25% in water absorption, 24% in permeable pore volume, 48% in absorption coefficient, and 46% in sorptivity. QBSCC mixes also exhibited resistance to chloride ion penetration and enhanced electrical resistivity. Moreover, using quaternary blends reduced the thermal conductivity and improved the energy efficiency.

Corrosion and volume stability of the blended SCC mixes containing induction furnace steel slag and crushed stone as coarse aggregate

Corrosion and volume stability of the blended SCC mixes containing induction furnace steel slag and crushed stone as coarse aggregate

Assessment of HVAF thermally sprayed coatings: Unraveling microstructural, electrochemical, and tribological performance using glass former Fe-Cr-Mo-Nb-B feedstock powder

In this paper the microstructural features of the glass former Fe68Cr8Mo4Nb4B16 coatings are unveiled and related to their electrochemical and tribological responses. The coating was mostly glassy with some embedded borides (M3B2, M2B-tetragonal; M being the metallic elements of the alloy) and ferrite. The tribological behavior of the HVAF coated sample, characterized by a thickness of about 200 µm, ∼6% porosity and a Vickers hardness of 357 HV0.5, was assessed in a sphere-on-plate configuration, revealing a specific wear rate of approximately 5 ×10−4 mm3∙N−1m−1. The wear mechanism was dominated by delamination caused by fragile intersplats. The corrosion resistance of HVAF coatings was evaluated in 0.6 M NaCl solution and compared with the results obtained for the crystalline Fe68Cr8Mo4Nb4B16 ingot, produced by melting in an induction furnace, and for the AISI 1020 steel substrate. The HVAF coating showed satisfactory corrosion resistance compared to the carbon steel substrate and the crystalline ingot, with the highest corrosion potential, Ecorr, values (−533 mVSCE) and the lowest corrosion current density, icorr, (10−6 A∙cm−2) followed by a clear passivation window upon anodic polarization in 0.6 M NaCl solution. Evaluations of HVAF coating showed a higher glassy content compared to the gas-atomized feedstock powders. This suggests that during spraying, certain particles were molten and experienced cooling rates adequate to inhibit crystallization, resulting in the freezing of the supercooled liquid. This phenomenon contributes to the good corrosion resistance observed in the present work and offers an opportunity to enhance the electrochemical behavior of HVAF coatings.

Application and challenges of layers of protection analysis (LOPA) in mining processes: Insights into benefits and limitations

AbstractLayers of protection analysis (LOPA) is a semiquantitative technique widely used in process industries for assessing hazardous scenarios and supporting risk‐informed decision making. It provides a balance between the simplicity of qualitative analysis and the detail of quantitative analysis. This paper discusses the authors' experiences with the application of LOPA in the mining and metals (M&M) industry, combined with traditional methods like HAZOP and HAZID, to identify risks. Several of LOPA's limitations became evident, and scenarios involving human factors, natural events, and asset integrity were excluded from analysis. Certain M&M processes, often complex and heavily reliant on manual operations, pose unique challenges to LOPA's effectiveness due to difficulties in isolating independent protection layers: for example, those involving induction furnaces where overheat scenarios can lead to explosive phase transitions upon contact with water and molten metal. Despite these challenges, the advantages of LOPA, such as enhanced understanding of protection layers and fostering effective safety improvements, are significant. The paper anticipates continued use of LOPA within the company, complemented by safety critical task analysis to manage human errors and enhance safety controls in critical situations.

Explainable Artificial Intelligence Approach for Diagnosing Faults in an Induction Furnace

For over a century, induction furnaces have been used in the core of foundries for metal melting and heating. They provide high melting/heating rates with optimal efficiency. The occurrence of faults not only imposes safety risks but also reduces productivity due to unscheduled shutdowns. The problem of diagnosing faults in induction furnaces has not yet been studied, and this work is the first to propose a data-driven framework for diagnosing faults in this application. This paper presents a deep neural network framework for diagnosing electrical faults by measuring real-time electrical parameters at the supply side. Experimental and sensory measurements are collected from multiple energy analyzer devices installed in the foundry. Next, a semi-supervised learning approach, known as the local outlier factor, has been used to discriminate normal and faulty samples from each other and label the data samples. Then, a deep neural network is trained with the collected labeled samples. The performance of the developed model is compared with several state-of-the-art techniques in terms of various performance metrics. The results demonstrate the superior performance of the selected deep neural network model over other classifiers, with an average F-measure of 0.9187. Due to the black box nature of the constructed neural network, the model predictions are interpreted by Shapley additive explanations and local interpretable model-agnostic explanations. The interpretability analysis reveals that classified faults are closely linked to variations in odd voltage/current harmonics of order 3, 11, 13, and 17, highlighting the critical impact of these parameters on the model’s prediction.

RESEARCH OF THE QUALITY OF CAST ROLLED ROLLS

A study of the influence of the frequency of the inductor of induction furnaces on the structure and hardness of rolled cast iron was carried out. The research was carried out using SPHN and SSHHN cast iron. As a result of the conducted research, it is shown that when using induction furnaces with different frequency of the inductor, the properties and structure of their working layer differ. The hardness of cast rolls from higher frequency furnaces is found to be lower than from furnaces with a lower frequency of the inductor. Therefore, such conditions affecting the hardness of the rolls as chemical composition and cooling mode remain constant.

The comparative study of Ti-bearing oxides introduced by different methods

Abstract The Ti-bearing oxides are introduced into HRB400 steel melt through external addition method (EAM, TiO2) and internal precipitation method (IPM, Ti alloy) using a vacuum induction furnace, respectively. For each experiment, the instantaneous evolution of oxide properties was investigated through the analysis of intermediate samples. For the EAM method, it was found that the titanium content gradually increased with increase in the treatment time. Similar increasing trend is also observed for Ti-bearing oxide properties, such as the number density and normalized titanium content. These phenomena are totally different from those in the IPM intermediate samples, in which both Ti content and Ti-bearing oxide features show rapid increase, reaching saturation at 1 min after the addition of Ti alloy, and remain relatively stable thereafter. This comparison hints that after TiO2 addition, they first dissolve in molten steel, then decompose, and finally again form Ti-bearing oxides. Furthermore, in the case of similar titanium content, EAM intermediate samples exhibit higher Ti-bearing oxide number density and higher normalized titanium content compared to IPM samples. After heat treatment, the intragranular ferrite nucleation was observed in cast sample of EAM, which was induced by the introduced Ti-bearing oxides.

سباكة الصلب عالي السبائكية AISI321 باستخدام السباكة الرملية

In this work, sand casting was used to obtain high-strength steel AISI-321 by melting alloy AISI304 using sand casting. This is in addition to titanium using an induction furnace, which is considered one of the metal forming processes that originated from the principle of casting in sand molds. In general, Ti will oxidize quickly in the melt if it is exposed to air in typical sand/investment casting processes; Titanium element provides greater resistance to inter granular corrosion. Stainless steel alloy 321, which differs from 304 in that it contains a percentage of titanium, which has given it the property of being used at high temperatures, which has increased the need or demand for stainless steel casting in some industries and due to the difficulty and complexity of producing some pieces or parts using SS304 (wrought) forging alloy by Machines, so that it became necessary to search for a way to improve quality and reduce time and cost, using plumbing technology, although information about this technology is not available in open references. The ability to cast stainless steel is affected by a variety of factors, such as the time and degree of melting, the types of additives, and the time of total solidification. In addition, there are some other casting factors that have a direct impact on the quality of casting stainless steel, such as the sand mold materials, their type, preparation of the sand mold, and the heat treatment steps. This research includes two parts, a theoretical part that includes the steps of sand casting, and the second part related to the practical side, where the effect of some casting factors was studied, which includes the weight and quantity of addition of titanium (300 to 1000 grams), the time of addition and pouring from (3 to 15 minutes), as well as a study of heat treatment and its effect. This is due to the quality of the stainless steel alloy under study. In each experiment, 100 kilograms were used on stainless steel 321 and 304. The practical experiments were completed in several experimental stages, and in each stage, some modifications were made so that they were based on previous results. The results of the chemical analysis of the last five samples showed a gradual increase in the amount of Ti% until it reached about 0.4%. The tensile strength and yield strength were at acceptable values compared to the Wrought SS321 and cast SS (CF) alloys, an austenitic stainless steel, where the lowest value was (200 and 198) MPa and the highest value was (559 and 315) MPa, respectively. The hardness values were between (145 to 149). Key words: sandcasting, Austenitic SS321, SS304, FeTi.

Electromagnetic processing of molten copper alloys in the induction furnace with cold crucible

Electromagnetic processing of molten copper is provided in a special kind of electrical furnace called an induction furnace with a cold crucible (IFCC), making it possible to successfully remove impurities from the workpiece. In order to analyze the process in a sufficient way not only electromagnetic, thermal and flow but also metallurgical and mass transfer phenomena in the coupled formulation should be taken into consideration. The paper points to an analysis of the kinetic process of lead evaporation from molten copper. It was shown that mass transport in the gas phase determines the rate of the analyzed evaporation process. The possibility of removal of lead from molten copper is analyzed and described.

Design and Numerical Study of Induction-Heating Graphitization Furnace Based on Graphene Coils

Induction-heating graphitization furnaces are widely used to produce high-purity graphite products due to their high heating rate, high-limit temperatures, safety, cleanliness, and precise control. However, the existing induction-heating systems based on copper coils have limited energy efficiency. This paper proposes a new induction-heating graphitization furnace based on graphene coils. Due to the excellent high-temperature resistance of the macroscopic graphene material, the coil can be placed closer to the graphite heater, which improves the electromagnetic efficiency; the coil itself does not need to pass cooling water, which reduces the heat loss of the furnace and ultimately results in a higher energy efficiency of the induction furnace. In this paper, a numerical model of the induction-heating process is established and verified, the temperature-field and electromagnetic-field distributions of the heating process are analyzed by using the model, and the energy balance calculations are performed for the original furnace and the new furnace. Through a comparison, it was found that the new furnace possesses an electromagnetic efficiency of 84.87% and a thermal efficiency of 20.82%, and it can reduce the energy consumption by 33.34%, compared with the original furnace. In addition, the influence of the coil parameters on the performance of the induction furnace is discussed. By changing the coil conductivity, the induction furnace can achieve an energy efficiency of 17.76%–18.11%. This study provides new ideas for the application of macroscopic graphene materials in high-temperature induction heating.

Solar cavity receiver for melting zinc metal

Concentrating solar power technologies can be applied to reduce the cost and carbon footprint of zinc melting processes. This study aims to improve the knowledge related to small-scale solar melting using a dish concentrator. This technology can be applied to zinc production as well as a range of small-scale applications, such as casting, recycling, galvanisation, and thermal storage. An experimental and analytical analysis of a rotating cylindrical cavity receiver for the indirect melting of zinc metal using concentrated solar power is presented. A multi-facet parabolic dish with an incident area of 2.85 m2 was considered together with a rotating cylindrical cavity receiver. The receiver had an aperture diameter of 0.2 m and the capacity for housing 17 kg of zinc. Five experimental test runs were executed, during which up to 73.5 % of the zinc inventory could be tapped from the receiver in its molten state, and average thermal efficiencies of up to 42 % were achieved. A predictive analytical model considering wind speed, wind direction, and direct normal irradiance was developed and validated against experimental data. A heat transfer efficiency factor was experimentally determined to account for voids in the zinc feedstock. The model was used to predict that approximately 41 kg of molten zinc could be tapped from the experimental setup throughout a typical day with a peak direct normal irradiance of about 900 W/m2 and an average wind speed below 2 m/s. A case study highlighted that energy savings of 0.6 kWh are achievable per kilogram of zinc processed by concentrated solar power rather than the conventional induction furnace.