Steel Melt Research Articles

Ultra-short-term Forecasting Study of Power Load in Mega Steel Industry Based on Multi-stage Modeling

Background: In the large-scale steel industry, significant power load variability, especially during processes like steel smelting, poses challenges to power system safety. Although there is an abundance of research and patents related to load forecasting, studies and patents specifically addressing large industrial load forecasting are sparse. Hence, accurate ultra-short-term load forecasting becomes particularly crucial. Objective: This study proposes an innovative method for ultra-short-term load forecasting to improve prediction accuracy during peak periods and mitigate risks in high-load conditions. Methods: We introduce an LSTM-XGBoost model enhanced by a random forest network and an improved grey wolf optimization algorithm (IGWO) for feature selection and parameter optimization, respectively. Results: Compared to other advanced models, our method demonstrates superior performance across key indicators such as MAPE (1.93%), RMSE (220.81), and R2 coefficient (0.99), and the prediction error is lower during both peak and off-peak periods. For instance, the proposed model achieved a MAPE improvement of over 25% compared to traditional models. Validation with data from multiple time periods confirms the model's accuracy and robustness. Conclusion: The proposed forecasting method effectively tackles load fluctuations in the steel industry, supporting safe and economical power system operations. Future research will aim to further improve peak identification accuracy and enable continuous adaptive learning.

Analysis of Microstructure Molecular Dynamics and Slag–Metal Reaction of Low‐Basicity CaOSiO2Al2O3MgO System Refining Slag

To clarify the effect of slag composition changes on the slag–metal interface reaction, the microstructure of the CaOSiO2Al2O3MgO system molten refining slag is analyzed using molecular dynamics simulation. In the simulation results, it is shown that in the slag, the SiO bond and AlO bond mainly exist in a tetrahedral coordination, mainly including five structural forms: Q0, Q1, Q2, Q3, and Q4. In addition, AlO also exists in a pentahedral and hexahedral coordination. With the increase of basicity, the proportion of aluminum–oxygen tetrahedral structure in the slag increases, the AlO bond length decreases, and the average diffusion ability of each atom in the slag increases, which can promote the reduction of aluminum in the slag into the steel melt. With the increase of Al2O3 content, the degree of slag polymerization increases, the proportion of pentacoordinated and hexacoordinated aluminum increases, the AlO bond length increases, and the average diffusion ability of each atom in the slag decreases, which can inhibit the reduction of aluminum in the slag into the steel melt.

Corrosion Behaviour of Magnesia-carbon Refractories by High Manganese Steel Melts

Corrosion Behaviour of Magnesia-carbon Refractories by High Manganese Steel Melts

INVESTIGATION OF THE INFLUENCE OF TECHNOLOGICAL FACTORS IN THE SMELTING OF LOW-ALLOY STEEL ON RESISTANCE TO HYDROGEN CRACKING

In the last decade, the oil and gas industry has been in dire need of seamless steel pipes resistant to corrosion destruction, which is associated with the development of oil production containing large amounts of hydrogen sulfide and other aggressive impurities. A key role in achieving high indicators of resistance to hydrogen cracking is given to the development and use of methods for controlling the type, quantity, size and morphology of non-metallic inclusions, forms of impurity presence, precipitation of non-metallic excess phases or strengthening structural components. The authors analyzed the current technology for smelting and casting of 13HFA steel at the KSP Steel PB LLP enterprise and developed a set of technological measures for smelting, extra-furnace treatment and casting of 13HFA steel, ensuring a high level of resistance to hydrogen cracking. A series of melts carried out according to the developed technological indicators ensured the achievement of the main HIC indicators at the level of CLR and CTR = 0 %. The research was conducted within the framework of grant funding from the Science Committee of the Ministry of Science and Higher Education of the Republic of Kazakhstan under the competition for grant funding for scientific and (or) scientific and technical projects for 2024–2026 under the project AP23487674 «Complex processing of bauxites of Kazakhstan with additional extraction of iron by alternative reducing agents in the implementation of the low-carbon development strategy». Keywords: low-alloy steel, hydrogen cracking, smelting, out-of-furnace processing, continuous casting.

Study of the Process of Processing Electric Steel Melting Dusts by the Method of Physicochemical Modeling

A physicochemical model of the recycling process of electric steelmaking dusts (ESM) with obtaining granulated pig iron and ZnO has been developed. The principal possibility of ESM dust processing by the proposed technology has been demonstrated. According to the model it is revealed that the main compounds in pig iron are Fe3C, Fe and FeS with the content, % by mass, respectively: 95,1 Fe; 4,89 C; 0,01 S, and in zinc-containing fumes, ZnO prevail with content 65,43 % by mass. The obtained modeling data are confirmed by the results of laboratory experiments on charge melting.

A new process route for the additive manufacturing of a high nitrogen containing martensitic stainless steel - A feasibility study

High-nitrogen martensitic stainless steels, such as X30CrMoN15 (0.3 to 0.5 mass% nitrogen), exhibit an excellent combination of strength and corrosion resistance, making them well-suited for applications in the medical technology and aerospace industry. The qualification of these steels for additive manufacturing (AM) could generate new application areas where AM, due to its process-specific advantages, could offer added value compared to conventional manufacturing methods. However, the laser powder bed fusion (PBF-LB/M) of high-nitrogen alloyed steels is challenging due to the high tendency for gas pore formation, resulting from the limited nitrogen solubility in the steel melt. In this work, a new process route for AM of a high nitrogen containing X50CrMoV15 martensitic stainless steel is presented, which consists of a process combination of powder nitriding, PBF-LB/M and subsequent hot isostatic pressing (HIP) with integrated quenching. Gas nitriding is used to achieve a nitrogen content in the starting powder that exceeds the maximum solubility in the melt. Although the nitrogen content decreases during the PBF-LB/M process, the high solidification and cooling rates prevent the melt from reaching equilibrium nitrogen levels, resulting in a nitrogen content above the solubility limit in the final PBF-LB/M state. The pores formed during the process are closed through HIP, which also allows hardening via integrated gas quenching. With an additional cryogenic treatment, the process produces a fully dense steel with 75% martensitic structure and 0.246 mass% nitrogen. Further optimization opportunities have been identified and are discussed.

The effect of complex extra-furnace treatment of metal melts on the formation of non-metallic inclusions in large-sized ingots

Abstract The article presents the results of studying non-metallic inclusions (NI) after extra-furnace treatment of the 13Cr9Mo2Co1NiVNbNB steel melt to produce large-sized ingots. The objects of the study were laboratory samples (the first batch), and samples obtained after melting in industrial furnace, followed by modification and double vacuuming (the second batch). Previously, using the Fact Sage software, modeling of the NI formation processes was carried out. The data were obtained on the possible NI composition and amount in this steel. The composition, the contamination index, parameters of NI in samples have been studied. It was established that in the samples of the first batch, the main part of the NI consisted of chromium- and manganese-containing oxides, which occupy more than 94% of the total area of the NI. In the samples of the second batch, the main part of the NI was represented by aluminum containing systems. It was shown that the average size of NI in the samples after extra-furnace treatment differs slightly (5%–12%), however, the contamination index in industrial samples after vacuum treatment and especially after modification and repeated vacuum treatment was reduced by more than 10 times. The results obtained allow to recommend vacuum treatment and complex modification with calcium and boron as measures to prevent the formation of NI and to improve metallurgical quality when smelting large ingots using complex alloy steels.

A Study of the Possibility of Producing Annealed and Metallized Pellets from Titanomagnetite Concentrate.

The current intensive development of steelmaking is being impeded by a scarcity of pure scrap. The potential to replace pure scrap with metallized raw materials that are naturally alloyed with vanadium and titanium, such as annealed unfluxed titanomagnetite pellets, could facilitate the achievement of key objectives in metallurgical development, particularly in the smelting of electric steel. The objective of this research was to produce annealed and metallized pellets from titanomagnetite concentrate under laboratory conditions, with the intention of further processing them as a commercial product in a blast furnace or as an intermediate product for the production of hot briquetted iron (HBI). The results demonstrate that pellets derived from titanomagnetite concentrate exhibit sufficient compressive strength (up to 300 kg/pellet) and a degree of metallization exceeding 90%, which aligns with the requirements for electric steelmaking. The suitability of pellets derived from titanomagnetite concentrate for use in both blast furnaces and metallization processes has been corroborated.

Effect of the method of estimating the mass of ferriferrous residue in EAF on the course and performance of smelting of stainless steel

Effect of the method of estimating the mass of ferriferrous residue in EAF on the course and performance of smelting of stainless steel

Gypsum Binder With Increased Water Resistance Derived From Membrane Water Desalination Waste

ABSTRACTA method has been developed for separating a mixture of calcium, magnesium and sodium sulfates obtained through the interaction of sulfuric acid and waste from the water purification process generated by using membrane filters. The primary goal of this method is to extract gypsum and produce gypsum‐based binders. Patterns were identified regarding how various types, ratio and quantities of additives: blast furnace slag, granite screenings, portland cement, electric steel smelting slag affect the water‐gypsum ratio, strength properties, and water resistance of high‐strength gypsum binders. It was found that adding a single‐component additive specifically to enhance water resistance does not significantly impact these properties. Complex additives have been developed based on Portland cement, granulated blast furnace slag, electric furnace slag, expanded clay dust, and granite screenings of various fractions. These additives are designed to maximize the water resistance of high‐strength gypsum binder based on synthetic calcium sulfate dihydrate. As a result, the water resistance coefficient increased from 0.45 to 0.52. Additionally, a technological block diagram of the process has been proposed.

Joint formation mechanism and mechanical properties of laser brazed Zn coated steel under different defocusing conditions

Laser brazing, producing a class-A joint surface in automotive, relies on the defocus control to manage laser heating mode and braze performance. This work demonstrates that the laser interaction mechanism transitioned from keyhole welding to conduction brazing as defocus distances increased from −20 to ≥18 mm while keeping other parameters consistent. Uniform brazed joints were achieved at defocuses of +22, +25 and + 30 mm. Increased defocus distance resulted in a wider bead, with a larger laser irradiation area and expanded heat affected zone (HAZ), leading to increased steel melting and more Fe-rich precipitates within the Cu braze. The interfacial reaction layers remained Fe(Si) with increasing thickness as defocus changed from +22 to +30 mm, and two distinct Fe(Si) phases were initially identified. The steel Zn coating evaporated upon direct laser irradiation at upper two regions while participated in interfacial reactions at the weld root. At the weld root, a dramatic phase transition from Zn–Cu to Cu was observed, with liquid Zn(Cu) phases particularly forming in joints with a +30 mm defocus, led to solidification cracks that acted as failure initiation sites during tensile testing. Cracks propagated along the interfacial reaction layer/bead interface, or along large Fe-rich precipitates within the bead. A +30 mm defocus produced a lower hardness HAZ than with a +22 mm defocus, due to the higher content of bainite and tempered martensite resulting from a slower cooling rate. This work provides insights into optimizing laser brazing parameters for Zn-coated steel.

Impact of CO2 as an oxidant on the decarburization and chromium retention and an approach for CO2 recycling

This study explores the unique role of CO2 as an oxidant in stainless steel smelting, focusing on its effectiveness in decarbonization and chromium retention. The research begins by theoretically demonstrating that although the introduction of CO2 increases the CO partial pressure in the reaction system, the decarburization and chromium (Cr) retention capabilities of CO2 can still be stably maintained through the rational adjustment of the molten steel composition, temperature, and inert gas proportions. Further experimental findings indicate that chromium does not exhibit significant oxidation losses when the carbon (C) content exceeds 1.0% (mass). Finally, a novel CO2 recovery and utilization approach is proposed, integrating CO2 capture from smelting flue gas and recycling it for smelting, reducing O2 consumption and energy costs. This innovative process, compatible with existing smelting plants, presents a promising pathway towards carbon neutrality in the iron and steel industry, bridging theoretical insights with practical applications.

Removal and distribution behaviors of inclusion particles in the steel melt under different rotation modes during continuous casting

This work investigated the removal and distribution behaviors of non-metallic inclusion particles caused by the flow of molten steel under two rotational modes, i.e. from edge to center (E-C) and from center to edge (C-E). Three-dimensional mathematical models discovering the relation between fluid flow, temperature distribution, solidified shell growth of large round bloom, and the movement of inclusions were established to investigate the mechanism of the differences. The obtained results show that under the C-E rotational mode, the removal rate of inclusions is 7 times and the highest local agglomeration number density of inclusions is reduced by 38.4 % compared to the E-C rotational mode. The current work proposes that the C-E rotating flow of molten steel can effectively raise the removal and uniform distribution of inclusions, thereby providing a new strategy for effective control of inclusion during the continuous casting process utilizing the novel electromagnetic metallurgy.

Thermodynamic and Kinetic Behavior Study of Gas Bubbles in High‐Temperature Steel Melts

This study provides an exhaustive exploration of the thermal expansion of low‐temperature argon bubbles in high‐temperature molten steel and the resulting dynamic effects. The energy equation of compressible fluid simultaneously with the volume of fluid model under the Euler framework is solved. The generation and rising behavior of bubbles are validated through rigorous physical water model experiments. Findings reveal that, within a heating time of 0.2–0.45 ms, gas bubbles already complete 65–90% of their internal energy increase. The total heat transfer time and heat transfer coefficient of bubbles exhibit distinctive patterns influenced by the initial diameter and temperature of the bubbles. Specifically, under the conditions studied, bubbles exhibit a total heat transfer time of ≈20–60 ms, accompanied by a heat transfer coefficient ranging from 500 to 2600 W (m2 * K)−1. During the thermal expansion process, gas bubbles experience energy transfer and conversion within the two‐phase flow. This article establishes a dynamic model describing bubble thermal expansion in steel melts based on underwater bubble dynamics’ first principles. The model provides a quantitative depiction of instantaneous changes in bubble size, velocity, and kinetic energy under specific conditions.

In Situ Observation of Precipitation Behavior of MnS during Solidification of Steel Melt Intended for Production of Nonquenched and Tempered Steel

Two heats of steel are melted using a vacuum induction furnace in the laboratory, with one heat undergoing magnesium treatment and the other being subjected to a combined magnesium–calcium treatment. The precipitation and agglomeration behaviors of inclusions of these two steel samples are observed using a high‐temperature confocal laser scanning microscopy. MnS precipitates form around oxide cores and undergo rapid growth during the solidification process of molten steel, and these MnS precipitates with oxide cores react with the cores, resulting in the transformation of the MnS into complex sulfides. In comparison with Al2O3 inclusions, MgO·Al2O3 inclusions have a lower critical velocity (V c), making them more susceptible to being engulfed by the solid–liquid interface. As the size of colliding inclusions increases, the coalescence–collision frequency (E 0) initially decreases until it reaches a minimum value. After that, with further size increments, the frequency starts to increase. During the inclusions growth process through collision, there is a distinct zone where coalescence–collision frequency is low. Inclusions that reach this zone struggle to grow further due to reduced collision coalescence, consequently leading to a predominance of inclusions with diameters in this zone.

Thermodynamic modeling of cobalt and nickel reduction using hydrometallurgical enrichment concentrates for steel alloying

The article provides studies on reduction processes in model thermodynamic systems and processes of nickel reduction from nickel concentrate and cobalt and nickel from cobalt-nickel concentrate. Concentrates are obtained during hydrometallurgical enrichment of polymetallic manganese-containing ores of the Kemerovo region – Kuzbass. By thermodynamic modeling using TERRA software complex, it was determined that nickel can be completely reduced from oxide in the NiO – C system at a carbon consumption of 0.08 kg/kg NiO, and at a carbon consumption of 0.15 kg/kg NiO ‒ in the NiO – Fe2O3 – C system. It was found that cobalt reduction in the CoO – C system begins at a temperature of about 513 K at any carbon consumption. With a further increase in temperature, the reduction process depends only on consumption of the reducing agent. From the obtained thermodynamic modeling data, it follows that cobalt reduction from the cobalt-nickel concentrate begins at a temperature of about 513 K and subsequently depends slightly on temperature. The extraction of cobalt increases with the amount of reducing agent at temperatures up to 553 K, then remains constant up to 1473 K temperature. Nickel reduction takes place at a temperature above 473 K. The degree of nickel reduction slightly depends on the temperature and amount of reducing agent at consumption of the latter over 0.02 kg/kg of concentrate. Laboratory studies showed that during the melting period, nickel can be reduced from its oxide almost completely with solid carbon, since nickel has less sensitivity to oxygen than iron. Theoretical and experimental studies of steel direct alloying showed that it is advisable to use a solid phase process in reduction of nickel and cobalt. Nickel concentrate and cobalt-nickel concentrate during steel smelting in an electric furnace is advisable to be introduced into charge in the form of mixtures pelletized with a carbonaceous reducing agent.

New magnetic proxies to reveal source and bioavailability of heavy metals in contaminated soils

Environmental magnetism plays an important role in monitoring heavy metal pollution, but most studies are confined to indicating only the levels of heavy metals using magnetic parameters. This study established new magnetic proxies for accurately depicting the sources and bioavailability of heavy metals in contaminated soils. We observed different relationships between χ and SIRM in the soils contaminated by non-ferrous metal smelting compared to those polluted by coal combustion and steel smelting. Furthermore, we found that the soft magnetic components (IRMsoft) in the soils were mainly controlled by the non-ferrous metal smelting activities, while the hard magnetic components (HIRM) might be affected by the iron erosion. These new magnetic proxies enriched the source composition spectrum and improved the accuracy of the source apportionment analyses (principal component analysis and positive matrix factorization), yielding a result that was comparable to that by Pb isotope fingerprinting. We also found strong relationships between magnetic parameters (especially IRMsoft) and bioavailable fractions of heavy metals, indicating that magnetic measurement may be a powerful tool for monitoring the bioavailability of heavy metals. This study expands the application fields of magnetism in environmental science research.

Interaction of iron melt with tungsten and WFe composite structure evolution

Development of new plasma facing components (PFC) draw attention of numerous scientific groups in fusion energy field. Tungsten as a main PFC material main have poor machinability, thus various designs were proposed to overcome this problem. However, such technologies as functional graded layers, sintering and additive technologies are limited in production size and have low cost-efficiency. This research considers the alternative approach of steel melt injection or melt infiltration of tungsten mesh. The results obtained establish the mechanism of phase evolution during interaction of solid W with liquid steel and iron. Energy dispersive spectroscopy, X-ray diffraction and Thermocalc calculations used to analyze the phase composition of tungsten wetted with various steels and pure iron. Results show that interaction rate significantly depends on melt temperature and overheating above its liquidus. Then the overheating exceeds 150 °C erosion of tungsten occur.

Investigation into microstructure, mechanical properties, and compressive failure of functionally graded porous cylinders fabricated by SLM

As the utilization of additively manufactured (AM) functionally graded porosity (FGP) structures continues to rise in various industries, there is a growing need for a comprehensive understanding of their design, microstructure, mechanical behavior, and failure mechanisms. This study involves the design and fabrication of FGP specimens with an 85 % volume fraction using selective laser melting (SLM) and 316L stainless steel powder, focusing on characterizing porosities, printing quality, and microstructure. Experimental tests, including tensile, quasi-static compression, and Split Hopkinson Pressure Bar tests, are conducted to assess the material behavior. Additionally, finite element analysis (FEA) and experimental compression tests are employed to investigate the compressive mechanical behavior and failure modes of FGP structures. The findings indicate that porosity distribution has minimal impact on the compressive behavior, specific energy absorption (SEA), and toughness of FGP structures. Furthermore, reducing the volume fraction from 85 % to 75 % in the S1FG samples increases the SEA by 7.2 % and changes the toughness by 5.9 %. Notably, porosity distribution influences fracture position and failure mechanisms during compression tests.

Temperature Monitoring System for 3 Phase Electric Arc Furnace (EAF) Transformer Cooling

The Electric Arc Furnace (EAF) transformer is a key component in the steel melting system using a furnace. The transformer functions to convert the electrical voltage from the main electrical network into the electrical voltage needed to form an electric arc in the melting furnace. In this research, the EAF transformer configuration uses a delta-wye configuration with a furnace melting capacity of 10 kg nickel ore. In its working system, this transformer will produce a very high current when the melting system is running. So this process will produce excessive heat on the EAF transformer side. As a result of the significant heat generated in the melting process, this transformer is equipped with a cooling system in the form of transformer oil which is a heat release medium and maintains the correct operating temperature. An appropriate temperature monitoring system will increase the work efficiency of the transformer and prevent excessive damage to the system. The sensor used in the design is the RTD PT 100 sensor which is installed at 7 measurement points. The main controller for data collecting and data processing used is a Siemens PLC. Data that has been processed on the main control device is transmitted to the IoT cloud server using a V-box device. As a human machine interface (HMI) web SCADA is used to read data in real time. From the results of the tests that have been carried out, the highest error presentation value obtained in measurements on the T phase is 0.05%. Meanwhile, when measuring the transformer oil sensor, an error value of 0% was obtained.