The applicability of classical heterogeneous nucleation theory for an inoculated Al-18.6Si (wt pct) alloy was investigated. Nucleation model proposed by Perepezko was used to study heterogenous nucleation of primary silicon in phosphorus-inoculated alloys. For this system, the nucleation temperature was found to be the most crucial variable in the model. If a spherical cap model is assumed for heterogenous

The prediction of precipitated graphite nodules size and distribution in a large industrial casting is critical to understand the mechanical behavior of cast iron components used in heavy vehicles. An accurate prediction of the graphite nodules requires a validated and integrated macro-micro modeling framework, which forms the motivation behind the present study. Classical theories in the literature

The carburization roasting treatment followed by the magnetic separation is an effective way to utilize low-grade siderite, in which the sodium sulfate additive plays an important role. In order to investigate the role of sodium sulfate additive, the present study fixes its particular attention on the function mechanism of sodium sulfate additive during the preheating treatment, carburization, and

Manganese is an important metal for steelmaking. Data on the density of the metal are scarce and show considerable scatter. Present work reports the density of the liquid manganese in the range of 1535 K to 1836 K estimated for the first time with the use of the maximum bubble pressure technique. The obtained density of the manganese is marginally higher than previously reported in the literature.

Surface transformation treatments like laser surface melting and laser surface hardening have been mostly developed in austempered ductile iron and gray cast iron. In this work, we explore the effects of the linear laser energy of the treatment on the microstructure, chemical composition, and hardness of ferritic nodular cast iron, using a fiber delivery diode laser. We found changes in the microstructure

The evolution of non-metallic inclusions (> 10 μm) for the Si-killed stainless steelmaking process is studied. The effects of the slag basicity in the AOD (argon oxygen decarburization) process, Ca treatment, refractory in the casting ladle, impurities (Ti, Al) in scraps and tapping temperature in the AOD process on the evolution of the non-metallic inclusions are investigated using the thermo-chemical

A three-dimensional computational model, combining the large eddy simulation (LES) turbulent model, VOF multiphase model for air phase, and discrete phase model (DPM) for injected bubbles, was established to evaluate the effects of drag force, lift force, pressure gradient force, virtual mass force, and wall lubrication force on the fluid flow and spatial distribution of bubbles in a continuous casting

To promote the innovation of raw magnesium production technology, an integrated calcination and silicothermic reduction short process for magnesium production was experimentally studied on the laboratory scale in this article. The influences of the thermal decomposition temperature, silicothermic reduction temperature, pelletizing pressures and silicon ratio on the characteristics of producing the

Al4C3 particles form during the primary production of aluminum via molten salt electrolysis due to the carbon solubility and direct contact between bath, metal, and carbon anodes. Additional Al4C3 may form during melt processing through direct contact between the melt and carbonaceous materials. As a result of their small size and similar density to aluminum, removal of aluminum carbide particles can

Four different Cu-rich polymetallic concentrates are tested for volatilization of Sb and As during laboratory-scale roasting. The experiments are performed between 200 °C and 700 °C, at intervals of 100 °C and in an inert atmosphere. Sb volatilization is much less (maximum approximately 45 pct) than As volatilization (maximum approximately 95 pct) in these conditions at 700 °C. As volatilization is

Metallurgical grade silicon (MG-Si) contains iron (Fe) as its main impurity, where phosphorus (P) is occasionally enriched in the FeSi2Ti phase. Based on this phenomenon, the precipitation superiority of P in the silicon-iron-titanium (Si-Fe-Ti) phase was verified by Si-5Fe and Si-3Fe-2Ti (wt pct) alloy refining for MG-Si. Microscopic characterization showed that P enrichment in the Si-Fe-Ti phase

Effective recycling of zinc-containing industrial wastes, most importantly electric arc furnace dust, is of tremendous importance for the circular economy of the steel and zinc industry. Herein, we propose a comprehensive kinetic model of the combined carbothermic and metallothermic reduction of zinc oxide in a metal bath process. Pyro-metallurgical, large-scale lab experiments of a carbon-saturated

In this study, a comprehensive transient numerical model of electroslag remelting cladding process with dynamic mesh technology is simulated to study the effect of the applied power on the uniformity of melting layer depth along the height of the as-prepared compound roll. The multi-physics fields are solved by the ANSYS Parametric Design Language and Fluent simulation software. The simulation results

Gas-atomized nickel alloy ATI 718™ powders with a nominal particle distribution of 15 to 45 µm were used in a laser powder bed fusion (LPBF) additive manufacturing (AM) process for ten sequential builds without refreshing with new powder. The repeated feedstock use caused the particle size distribution, particle morphology, and oxygen content to change in comparison to virgin powder. Unusual particle

Electroslag remelting (ESR) technology has been adopted to recycle the rejected electrolytic manganese metal scrap. In this study, a transient 3D coupled numerical model accounting for the electromagnetism, multiphase flow, heat transfer, and solidification was elaborated and used to simulate the evaporation behavior of the molten manganese metal (MM) during the ESR process. The volume of fluid approach

The first- and second-order interaction coefficients of V in Fe-C-V melts were accurately measured using the chemical equilibrium technique, by equilibrating CaO-MgO-Al2O3-VOx slags with Fe-C melts under controlled oxygen potential for 24 hours at 1873 K (1600 °C). The argon was employed as the protective gas and a purification device was used to control the oxygen potential in the atmosphere. The

In this work, Mo was added into Al melt to reduce the detrimental effect of double-oxide film defect. An air bubble was trapped in a liquid metal (2L99), served as an analogy for double-oxide film defect in aluminum alloy castings. It was found that the addition of Mo significantly accelerated the consumption of the entrapped bubble by 60 pct after holding for 1 hour. 2 sets of testbar molds were then

Silico-ferrite of calcium and aluminum (SFCA) is the major bonding phase in iron ore sintering process and is critical to enhancing the sinter properties, such as reducibility and mechanical strength in subsequent blast furnace operations. The phase relations foundations of the alumina-free silico-ferrite of calcium (SFC) have been previously experimentally investigated in air by the authors (Chen

Based on two considerations of making full use of the residual heat of vanadium slag and exploring a novel green vanadium extraction process, this article employs vanadium slag with high MgO content as raw material, blowing oxygen into the molten vanadium slag and using the residual heat of the vanadium slag to carry out high-temperature roasting experiments. XRD and SEM/EDS were used to characterize

The application of CO2 for converter steelmaking results in several beneficial effects. However, limited studies have investigated the influence of CO2 and O2 mixed injection on jet flow field and whether jet characteristics can be improved by changing the layout of nozzle holes. This study used FLUENT® to simulate the jet distribution of the oxygen lance nozzle of a 120 t converter. First, the model

Experimental and theoretical studies have been carried out to investigate the effects of slag composition on the MgO·Al2O3 inclusion in ingot during the electroslag remelting (ESR) process with a focus on developing a mass-transfer model to understand the evolution mechanism of MgO·Al2O3 inclusion. H13 die steel was used as the electrode and remelted with two different kinds of slags by using a 30-kg

The Henrian activity coefficient of Nb and the interaction parameters of Mn and V to Nb in liquid iron at 1873 K (1600 °C) were accurately determined by using the chemical equilibrium technique. CaO-MgO-Al2O3-NbO2 slags with different compositions were equilibrated with liquid iron and Fe-Mn melts, respectively, to determine the Henrian activity coefficient of Nb in liquid iron, \( \gamma_{\text{Nb(Fe)}}^{\text{o}}

The breakthrough route involving a reduction shaft furnace operated with pure hydrogen gas (here called H2-SF) and the electric arc furnace is widely accepted as one of the most viable future alternatives for industrial-scale production of primary steel with minor CO2 emissions. It has been clarified that the largest portion of the total energy for the entire route is consumed by the H2-SF operation

More than 80 pct of copper matte in the world is refined by a Peirce–Smith converter (PSC), but there still exist a number of problems restricting the productivity of PSC. A novel view for improving the copper PSC process was proposed by investigating the bubble distribution and surface splashing through water model experiments. The operating parameters of tuyere diameter (d), liquid height (H), and

Existing experimental results of weldability tests show the susceptibility of carbon steels to solidification cracking varies significantly with the C content. To analyze the effect of the C content on the susceptibility, equilibrium solidification of binary Fe-C alloys was assumed as an approximation in view of the rapid diffusion of the interstitial solute C in Fe. First, the curve of the equilibrium

This paper investigates the effect of nitriding potential under well-defined gas nitriding conditions on the formation and growth of a compound layer called “white layer” on a FeAl40 (with the composition of 40 at. pct Al) iron aluminide alloy. The nitriding potential was systematically varied in the range of 0.1 to 1.75 bar−1/2 at 590 °C for 5 hour nitriding time with an ammonia-hydrogen-nitrogen

The effects of gas composition and the extent of reduction on the compressive strength of direct reduced iron (DRI) were investigated. Gas mixtures containing different proportions of hydrogen, carbon monoxide, water vapor, carbon dioxide and methane were tested. The structure of laboratory and industrial DRI was examined and correlated with gas composition and mechanical properties. After reduction

A new model, CONOFFLINE, has been developed to simulate transient thermal behavior of a longitudinal section down a continuous steel slab-casting machine. The model was first verified by comparing its predictions of shrinkage through the strand thickness with transient measurements of roll forces in a thick-slab caster during a series of speed changes. The model was then applied to investigate the

Solid-state thermal treatment of Ni sulfide concentrates in an inert or reducing atmosphere, and the presence of metallic Fe is proposed as a feasible route to produce ferronickel (FeNi) alloy while retaining S in iron sulfides. The present work investigated the effects of temperature and amount of Fe addition via a thermodynamic analysis, giving a suitable temperature of 973 K to 1173 K and metallic

The compositional dependence of the thermal conductivity of a molten copper-iron (Cu-Fe) alloy at low Fe contents was measured herein by combining a periodic laser heating method and an electromagnetic levitator (EML) with a static magnetic field that can suppress the melt convection in the molten sample. The measured thermal conductivities markedly decreased with the composition of Fe up to 20 at

In the current study, a two-dimensional mathematical model was applied to investigate the slag lubrication in continuous casting mold of slab through the acquisition of the average slag consumption per oscillation cycle and the shear stress acting on the shell. The thickness and the consumption of the slag in the shell/mold gap and the downward velocity on either side of the liquid slag were monitored

Silicon carbide nanowires are valuable for electronic and optical applications, due to their high mechanical and electrical properties. Previous studies demonstrated that nanowires can be produced easily, by mixing a silicon-based compound (Si or SiO2) with a carbon source (C or SiC), in an inert gas atmosphere (Ar or He). The result of this reaction is an elevated number of core–shell SiC-SiOx nanowires

To obtain fundamental information on the dissolution of cobalt into alumina-saturated MnO-SiO2-Al2O3 slags in the smelting reduction of spent lithium-ion batteries, the equilibrium distribution of cobalt between Co-Cu alloys and alumina-saturated MnO-SiO2-Al2O3 slags was measured at 1573 K and 1623 K under a controlled CO-CO2 atmosphere. The results show that (i) the solubility of cobalt in the slag

In this work, a dynamic model was established for the dephosphorization of metallurgical grade silicon by levitation refining. Particular emphasis was placed on the transport behavior of phosphorus in the liquid boundary layer, then at the melt surface and finally within the gas phase surrounding the levitated droplet. Within the melt boundary layer, and at the droplet surface, temperature was the

Calcium-containing ferrosilicon—FeSi(Ca)—does give much higher calcium yield than calcium disilicide during calcium treatment of steel under laboratory conditions, in line with industrial observations. Upon calcium treatment of both aluminum-killed and silicomanganese-killed steel, a new population of small calcium-rich inclusions forms. The results indicate that pre-existing (deoxidation) inclusions

The interaction between mineral phases in two commercial iron ores and flux materials (CaO, MgO, SiO2, and Al2O3) was studied under 0.5 kPa O2 partial pressure while heating to different temperatures. CaO was the most effective flux for liquid phase generation during sintering. For a hematite ore with few gangue components (Ore A), the formation of an initial liquid phase commenced at ~ 1275 °C, with

The interaction of different alloying elements has a significant impact on the mechanical and microstructural properties of steel products due to the thermodynamic and kinetic effect. This article presents a statistically developed and validated model for austenite decomposition during cooling, based on a set of experimental continuous cooling transformation diagrams available in literature. In the

Slag flow behaviour is critically important in the lower zone of the ironmaking blast furnace, and is closely related to the selection of charged raw materials, coke bed permeability, process stability and hot metal quality. To better understand the effect of slag properties on flow behaviour in the coke bed, a numerical approach was applied to characterize the slag flow through funnel analogues. These

Al-Ti complex deoxidation equilibria in high Cr stainless steels were studied by measuring the thermodynamic behavior of O in the Fe-Cr-Al-O, Fe-Cr-Ti-O, and Fe-Cr-Al-Ti-O melts. The present deoxidation experiments were thermodynamically analyzed along with available data in the literature using Wagner’s formalism. The compatible set of parameters for the multicomponent Fe-Cr-Al-Ti-O system was selected

TiO2-FeO-Ti2O3 slag system is the dominant system for industrial high-titania slag production. In the present work, viscosities of TiO2-FeO and TiO2-FeO-Ti2O3 systems were experimentally determined using the concentric rotating cylinder method under argon atmosphere. A viscosity model suitable for the TiO2-FeO-Ti2O3 slag system was then established based on the modification of the Vogel-Fulcher-Tammann

Magnetic-controlled Electroslag Remelting (MC-ESR) process has been proposed to improve the inclusion removal efficiency in recent years. In this study, the effects of axial static magnetic field (ASMF) on liquid melting film (LMF) and inclusion removal during this period in ESR process of GCr15 steel were studied by a series of MC-ESR experiments. The thickness of the characteristic position of LMF

In numerical computation of ladle metallurgy, multiphase models are essential. Still, these models are afflicted with great uncertainty, making a validation with experimental data mandatory. Validation experiments fundamentally differ from physical modeling experiments because emphasis is on a complete documentation of all boundary conditions and a detailed uncertainty assessment. For this work, the

In this research, the proposal to use a nonconsumable lance or heat pipe to decrease the mixing times in a secondary refining ladle is evaluated. The main idea is to minimize the stirring times to get the complete mixing of liquid steel, mainly due to the fact that a consumable lance once its melted changes the operation conditions. Use of a nonconsumable lance is well known because of its excellent

Slag entrainments in a continuous casting mold result in serious defects in steel products. Most previous studies concentrated on the magnitude of meniscus velocity or transient roll cell motion to investigate the cause of slag entrainment. However, slag entrainment is more directly connected with the meniscus vortex, which accompanies a meniscus deformation (e.g., vortex dimple or core). Most previous

Alumina inclusions generated from aluminum deoxidation may undergo several transformations depending on steelmaking conditions. Under reducing conditions, in contact with MgO-saturated slag, alumina inclusions are known to transform to spinel. However, there are uncertainties related to CaO pick-up by alumina-based inclusions. This work aims to provide some clarification of CaO pick-up by alumina inclusions

Purification of molten salt is essential for producing highly pure metal from melts by chemical reactions and electrolysis. Cementation is a technique used for refining molten ZnCl2-based salt. In this study, we investigated the thermodynamics involved in the reduction of CdCl2 in molten ZnCl2-based salt with Zn metal to optimize the separation conditions for Cd; this is difficult as both Cd and Zn

Particle size reduction inevitably occurs inside ironmaking blast furnaces (BFs) but is not studied under BF conditions due to the lack of an effective tool. This paper simulates this phenomenon inside a 5000-m3 commercial BF using a recently developed three-dimensional computational fluid dynamics (CFD) process model. In particular, the sinter reduction degradation and coke gasification are modeled

A transient three-dimensional comprehensive numerical model was developed to clarify the effect of electro-emulsification on sulfur mass transfer during the electroslag remelting process of rejected electrolytic manganese metal scrap. The magnetohydrodynamic thermal two-phase flow and solidification behavior were numerically clarified. The kinetics module was established to assess the sulfur mass transfer

Understanding and reducing air entrainment in liquid metals is important for improving casting filling systems and liquid metal transfer processes. Air entrainment generates oxide inclusions that reduce the mechanical performance of metals. This paper presents air entrainment measurements for a jet of liquid aluminum alloy A356 plunging into a pool. Measurements are performed in argon and air atmospheres

The effect of as-cast structure and macrosegregation on the mechanical properties of a direct-quenched low-alloy martensitic ultrahigh-strength aluminum killed and calcium treated steel cast at different superheats was studied. Samples from the castings were laboratory hot rolled with two different finishing rolling temperatures to distinguish the effect of hot rolling. Using optical emission spectrometry

Reduction of manganese and silicon oxides in smelting of silicomanganese causes significant changes in slag composition and properties: decreasing the ratio of non-bridging oxygens per tetrahedrally coordinated cations (NBO/T), increasing the slag viscosity, and decreasing diffusivities of slag components. These changes can have a strong effect on the kinetics of reduction reactions. This paper analyses

The campaign life of blast furnaces can be greatly limited by the interactions of carbon walls with liquid Fe-Csat. Numerous carbon forms have been investigated but not glassy carbon. In this work, liquid Fe-Csat catalyzed the graphitization of glassy carbon crucibles heated in a high-temperature confocal scanning laser microscope. Graphitization created readily wetted pores into which the hot metal

Precise control of dissolved nitrogen is required for producing Third-Generation Advanced High-Strength Steels (AHSS). Compared with well-documented thermodynamic data, the data on the kinetics of nitrogen dissolution in these steels are limited. The isotope exchange technique (15N–14N exchange reaction) was applied to measure the nitrogen reaction rate at different temperatures, on pure liquid iron

The precipitation of discrete iron-based intermetallic compounds (τ5c IMCs) is an inevitable phenomenon in a steel strip coating pot due to the dissolution of iron from the steel strip surface and temperature perturbations in the pot. These τ5c IMC particles are a primary source of coating inclusions and bottom dross buildup in the coating pot. It has been hypothesized that they will re-dissolve into

The cohesive zone is a region of low permeability in a blast furnace. This study shows the impact of the chemical composition of pellets on the metallurgical processes occurring in this region during the iron ore reduction process. Sixteen pellets containing varying contents of MgO, CaO, and SiO2 were investigated. The results indicate that increasing the MgO content of pellets improves their high-temperature

TiC was examined as a starting material for Ti metal production by sulfidation and electrochemical reduction in molten salt. The sulfur evaporation temperature, sulfidation temperature, and time were optimized in a dual-zone furnace for the efficient and sustainable formation of TiS2 as well as carbon removal from TiC by S2 gas sulfidation. A mixture of TiS2 and Ti2.45S4 powders was synthesized from

The strong interactions between the metallic elements and C in liquid Ni, Co, and Ni-Co alloys have been thermodynamically analyzed. The liquid solution properties in Ni-C and Co-C systems showed significant asymmetry because of the short-range ordering of C exhibited in the liquid solution. Using the modified quasichemical model in the pair approximation, the Ni-C and Co-C systems were re-optimized

The condensation behavior of magnesium vapor in argon was studied. Thermodynamic analysis showed that magnesium vapor condensation was controlled by partial pressure and temperature and that temperature was the main factor affecting condensation. When the actual magnesium vapor partial pressure was < 371.2 Pa, the magnesium vapor changed directly from gas to solid; when the vapor pressure was > 371

The flow pattern of molten steel in a mold of continuous casting affects the temperature distribution and initially solidifies the shell thickness homogeneity, inclusion transport, and liquid slag entrapment. Alumina inclusions in Al-killed steel tend to adhere to the inner wall of the nozzle, which changes the nozzle geometry structures and affects the molten steel flow pattern in the mold. In this