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To achieve the desired superheat of molten steel during the continuous casting process, optimization of process parameters such as molten steel temperature in ladle furnace, casting speed, and baking temperature is necessary. Therefore, obtaining the superheat corresponding to these process parameters in advance is particularly important. To address this issue, a model for predicting the temperature of molten steel in the tundish during continuous casting is designed. The model adopts a combined modeling approach of mechanistic model and data model. To address the issue of the mechanism model's inability to capture the variation of the lining's thermal parameters, this article improves the traditional physics-informed neural network (PINN) algorithm. It combines the constraints from both the forward and inverse problems, allowing for obtaining solutions to the equations while capturing the variation of equation parameters. Actual data from multiple casting sequences at a steel plant are collected to validate the accuracy and interpretability of the model. The results show that the error of the model is about 2.1k which has better accuracy compared to pure mechanistic model and pure data model. Additionally, it can capture the variation patterns of tundish lining thermal parameters under different operating conditions. Therefore, the model designed in this article can provide both profound physical interpretation ability and more practical predictions of molten steel temperature. [ABSTRACT FROM AUTHOR]

Computational models are powerful tools to quantify physical phenomena to gain valuable insights into a manufacturing process. Their accuracy is hindered, however, by uncertainty in the input data. Furthermore, when calibrating models with plant measurements, it helps to understand which variables have greatest effect on the critical model outputs. This work applies uncertainty quantification and sensitivity analysis to determine the most influential input parameters in the CON1D model of heat transfer and solidification in steel continuous casting with slag. Results show that the slag rim greatly affects heat flux near the meniscus, so control of its size is important. Heat flux and temperature down the mold depend greatly on velocity of the solid slag layer, and slag solidification temperature, which control the slag layer thickness, which in turn affects the interfacial resistance that controls heat transfer in the process. Scale formation on the mold coldface greatly increases mold temperatures. Based on the results presented here, models of heat transfer in continuous casting such as CON1D would benefit from plant measurements such as slag rim size and solid slag velocity, and lab measurements such as slag viscosity at lower temperatures, to better characterize this important slag property. [ABSTRACT FROM AUTHOR]

For more than 20 years, high‐temperature laser scanning confocal microscopy (HT‐LSCM) has become worldwide a proven technique for observing various metallurgical phenomena in situ. HT‐LSCM turns out to be a reliable and effective method for the observation of quantification austenite grain growth kinetics in steel, being highly relevant in casting and steel processing. In the present article, the measurement technique is briefly introduced followed by some basics on austenite grain growth. Finally, selected examples of recent research activities are discussed, including investigations into pure iron and the systems Fe–P, Fe–C, Fe–Al–N, and Fe–C–Nb–N. The influence of P on the grain growth kinetics is remarkable. At 1350 °C, the final grain size decreases from 255 μm in pure iron to 145 μm by adding 0.044 wt% P. In contrast, C enhances the grain growth in specific alloying ranges (0–0.30 wt%C), particularly at elevated temperatures. For a Al content of 0.025 wt% and only 50 wt ppm N, AlN loses the pinning effect above 1150 °C. In case of Nb(C,N), an elevated Nb content (0.085 wt%) provides stabilization of Nb(C,N) at 1150 °C, but at 1250 °C, no pinning of Nb(C,N) is visible anymore. [ABSTRACT FROM AUTHOR]

It is herein considered a new product composed of solid–liquid dispersion of a conveniently formulated continuous casting powder in synthetic oil‐based esters, where hypothetical limit to consider this liquid slurry as a liquid powder is a mix with at least 50% in weight powder load preserving suitable fluidity for effective and stable pumping. After a relatively long and intense industrial application period, one of most critical points when using liquid powder for steel continuous casting proves to be mold feeding. This is mainly because of weird properties of such material which behaves as a non‐Newtonian fluid. A thorough rheological study on samples of liquid powder for continuous casting is carried out. Based on meticulous characterization of a set of laboratory samples, the dispersion flow curve is determined. Most commonly used rheological models are then tested for fitting with the experimental data. Sisko model is identified as the best fitting one. This model is then implemented to derive the system curve describing its behavior under its industrial application conditions. The mathematical process to apply Sisko model and its numerical solutions is explained. The results found are consistent with the field experience of the industrial application of the material under study. [ABSTRACT FROM AUTHOR]

The application of a battery of bioassays is widely recognized as a useful tool for assessing environmental hazard samples. However, the integration of different toxicity data is a key aspect of this assessment and remains a challenge. The evaluation of industrial waste leachates did not initially undergo any of the proposed integration procedures. This research addressed this knowledge gap. Twenty‐five samples of waste foundry sands were subjected to a leaching test (UNI EN 12457‐2) to evaluate waste recovery and landfill disposal. The leachates were evaluated using a battery of standardized toxicity bioassays composed of Aliivibrio fischeri (EN ISO 11348‐3), Daphnia magna (UNI EN ISO 6341), and Pseudokirchneriella subcapitata (UNI EN ISO 8692), both undiluted and diluted. Daphnia magna and P. subcapitata were the most affected organisms, with significant effects caused by 68% and 64% of undiluted samples, respectively. The dilution of samples facilitates the calculation of EC50 values, which ranged from greater than the highest concentration tested to 2.5 g/L for P. subcapitata. The data on single‐organism toxicity were integrated using three methods: the Toxicity Classification System, the toxicity test battery integrated index, and the EcoScore system. The three classifications were strongly similar. According to all applied systems, three samples were clearly nontoxic (from iron casting plants) and two were highly toxic (from steel casting plants). Moreover, the similar ranking between undiluted and diluted leachates suggests the possibility of using only undiluted leachates for a more cost‐effective and time‐efficient screening of waste materials. The findings of this study highlight the usefulness of integrating ecotoxicological waste assessment. Integr Environ Assess Manag 2024;20:2294–2311. © 2024 The Author(s). Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC). Key Points: The toxicity of waste foundry sand leachates was assessed using three ecotoxicity tests, and the results were summarized using three different synthetic indices to assess the environmental risk associated with the possible reuse of these materials.The samples of cast steel and a binder system based on sodium silicate‐ester cured were very toxic and were associated with high environmental risk, whereas the samples of cast iron and different binder systems were associated with a very low level of risk.Classification systems are useful tools for responding to management and regulatory frameworks.Despite these findings, there remains a lack of development in the real‐world use of these systems in the waste management industry. [ABSTRACT FROM AUTHOR]

This review paper provides a comprehensive investigation on problems encountered in casting practices, integrating insights from diverse research areas within the field of sand casting along with the most probable and effective remedies of those problems. The study revolves around three main themes: the optimization of sand-casting processes, the selection of binders for sand-casting, and the transformative impact of artificial intelligence (AI) and advanced control systems in foundry and steel casting processes. Our paper also highlights the significance of both digital and manual optimization techniques in sand casting processes, emphasizing the transformative impact of AI technologies like Artificial Neural Networks (ANN), Fuzzy Logic, and Genetic Algorithms for enhancing efficiency, accuracy, and automation. These digital methods enable data-driven decision-making and continuous process improvement, leading to higher quality and reduced defects. Meanwhile, manual optimization, relying on the expertise and adaptability of foundry professionals, complements digital approaches by providing hands-on problem-solving and flexibility in complex scenarios. Manual optimization in sand casting involves hands-on activities that leverage the expertise and experience of foundry workers. Examples include adjusting the mold packing density to ensure uniformity, tuning the sand mixture composition for optimal mold strength and permeability, use of the binders to enhance the ratio of sand mixtures and placing sprues and risers to control metal flow and minimize defects. Together, these approaches enhance casting quality, reduce costs, promote sustainability, and maintain industry competitiveness, offering a comprehensive framework for modernizing sand casting. The main objective of this study is to offer a comprehensive understanding of how these areas converge to reshape and elevate the quality, efficiency, and sustainability of casting processes. The first section explores the optimization of sand-casting processes, that focus on critical factors such as mold types, molding sand composition, and process parameters. By identifying common grounds, including the influence of mold type on mechanical properties and the optimization of molding sand composition for reduced defects, this segment provides practical insights for achieving high-quality sand castings. The second section explores the choice of binder for sand molding, combining research from different studies that examined different natural and synthetic binders. Key findings, such as the optimization of binder content for specific casting requirements and the potential of natural binders as eco-friendly alternatives, offer guidance for practitioners seeking to enhance sand mold properties and overall casting quality. The third and final part explores the application of AI and advanced control systems in foundry and steel casting. The review highlights the transformative impact of AI techniques, including neural networks, fuzzy logic, genetic algorithms, and particle swarm optimization. These AI-driven approaches optimize customer order management, enhance supply chain efficiency, and improve green sand properties, contributing to the realization of Industry 4.0 concepts in casting processes. [ABSTRACT FROM AUTHOR]

Low‐basicity fluorine‐containing mold flux, which forms a porous slag film with NaF pores, is expected to solve the contradiction between heat transfer and lubrication in the continuous casting of peritectic steel. Herein, the kinetic mechanism and the influence of NaF gas formation based on the different fluorine raw materials (NaF, CaF2, and Na3AlF6) at 0.9 basicity and 6 wt% fluorine are investigated by the combination of experiments and calculations. The results show that CaF2 is the first to generate NaF gas at 1189 K, followed by Na3AlF6 (1238 K) and NaF (1328 K). NaF raw material produces the most NaF gas with the lowest activation energy in the three raw materials, due to high Na ion kinetic energy, the simple degree of polymerization, and Na‐F1 bonds. Correspondingly, NaF bubbles in the molten slag are the largest based on their aggregation. Na3AlF6 and CaF2 raw materials rank second and third, with F atoms primarily bonded as Al‐Fx and Ca‐Fx and the higher proportion of QSi−O−Al2$Q_{\text{Si} - \text{O} - \text{Al}}^{2}$ and QSi−O−Si4$Q_{\text{Si} - \text{O} - \text{Si}}^{4}$ structure. Notably, at 0.9 basicity and 6 wt% fluorine, Na3AlF6 as raw material generates a suitable amount of gas, making diffuse and fine NaF bubbles in the molten slag. [ABSTRACT FROM AUTHOR]

Diffusion bonding of additive manufactured (AM) metal parts to traditionally manufactured metal parts is an effective and low-cost way to produce large-scale and multi-functional parts. In this study, diffusion bonding of casting 45 steel and AMed 316L stainless steel was conducted with four different bonding surface roughness from large to small. The interface formation mechanisms including the metallic elements diffusion layer, the carbide layer and the interfacial grain boundary (IGB) migration were investigated in detail. The results show that the interface bonding ratio improves from 43 to 96% due to void closure as the roughness of the bonding surface decreases from Ra ~ 1.5 µm to Ra ~ 0.1 µm. The shear strength of the joint increases from 350 to 468 MPa, and the specific shear strength increases from 58 to 94%. The type and number of grain boundary migrations are significantly affected by the bonding surface roughness. The number of IGB migrations at the "triple junction" structure increases while the number of strain-induced grain boundary migrations decreases as the bonding surface becomes smoother. [ABSTRACT FROM AUTHOR]

The clogging of the submerged entry nozzle (SEN), as an important device to connect the tundish and the mold, has been widely concerned. However, until now, the clogging of the SEN cannot be eliminated during the casting. Herein, the clogging behavior of the SEN during the casting of ultralow‐carbon steel is studied using an external DC electric field. The findings demonstrate that the DC electric field inhibits the growth of the clogging on the outlet and the thickness of the clogging layer is small, which ensures the integrity of the profile of the outlet. After DC treatment, the interface of the clogging is clear and the density is increased, which reduces the pollution to molten steel. At the same time, the fluctuation of the mold level is significantly improved, and the defect rate of cold rolling is effectively reduced to 30% of the original level, which is beneficial to the overall performance of the slab. [ABSTRACT FROM AUTHOR]

In this article, a brief review of the development of the Knudsen effusion mass spectrometric (KEMS) approach in the Theoretical Metallurgy Department of the KTH Royal Institute of Technology and in the in the Laboratory of Metallurgy of the Helsinki University of Technology and modifications of quadrupole model QMG420 mass spectrometers, is presented. The thermodynamic data obtained from vaporization of standards, such as NaCl, CsCl, B2O3, and Ag, and of the B2O3–Al2O3 and ZnO–P2O5 systems is compared with the data obtained using a magnetic MS1301 mass spectrometer. For the first time, composition of the vapor phase over the Dy2O3–DyF3, CaO–CaCl2, and Cu–Mg systems and the partial pressures of components at high temperatures are investigated. The experimental data obtained for the investigated systems are used for prediction of the vaporization processes and modeling of thermodynamic properties and high‐temperature phase equilibria in the multicomponent systems used in metallurgy. An account is given of the detailed studies of the vaporization processes and thermodynamic properties of some multicomponent systems composed of oxides, fluorides, and carbonates forming mold powders for continuous casting of steel. Some new directions of the ongoing studies by the KEMS method are summarized. [ABSTRACT FROM AUTHOR]

When the severity of high-temperature environments increases, the oxidation mode changes from a normal oxidation mode, when a formed oxide layer protects the surface of austenitic heat-resistant cast steels, to an extreme mode, when scale spallation and partial vaporization intensify surface degradation. These processes can also influence each other. On the example of two oxidized austenitic heat-resistant steels with different alloying levels, we show how the described simulation/experimental methodology may be applied to analyze and quantify the synergetic kinetics of the extreme surface degradation processes. The surface degradation processes were formulated using diffusion-controlled parabolic oxidation, time-dependent vaporization, and spallation with an intensity cross-linked to the instantaneous thickness of the oxide layer. The 400 h tests were performed in air and water vapor-containing combustion gases at upper working temperatures. Three experimentally obtained surface degradation quantities included changing the weight of the specimen with adherent oxide, the weight of the spalled scale, and the thickness of the formed adherent oxide. These experimental quantities were used to compute the values of oxidation, vaporization, and spallation kinetic constants for each uninterrupted oxidation test. An additional interrupt every 100-h test was also performed to verify the model-predicted trends. It was shown that the alloying level in austenitic heat-resistant cast steel determines its ability to withstand surface degradation at extreme oxidation mode by the synergetic effects of oxidation, vaporization, and spallation. The described approach can be used for the metallic component lifetime prediction in severe gaseous environments. [ABSTRACT FROM AUTHOR]

In this study, D2 steel (Cr12Mo1V1) with different yttrium (Y) contents was designed, and the effects of Y on the inclusions and eutectic carbides of D2 steel after casting were analyzed by scanning electron microscopy, ASPEX, and electron probe microanalyzer. The results reveal that the inclusions in D2 steel without Y are mainly Al2O3 and MnS, while the inclusions with Y are mainly Y2S3, Y2O2S, and complex inclusions. When the Y content increased from 0 to 0.021%, the quantity of inclusions with an average grain size of 1–2 microns gradually increased from 47.6 to 64.7%. The chain eutectic carbides in D2 were broken and tend to be spheroidized after adding Y, which was attributed to the fact that the submicron Y-rich inclusions help to slow down the segregation of carbon and alloying elements. The inclusion is beneficial to the heterogeneous nucleation of M7C3 eutectic carbides and the decrease in eutectic reaction temperature. [ABSTRACT FROM AUTHOR]

Carbon steel is the most common steel alloy. Carbon steel may be the best-known industrial material for use in design for its economic value and reliability in performance. It is nonetheless challenging to find the information needed to efficiently design safe and reliable systems that are manufactured from carbon steel. Historically, carbon steels were considered to be the same material with the same properties and design values for all product forms such as forgings, bars, or plates, including castings. Now, designers want to know the properties and performance of steel components, based on the manufacturing process as well as the alloy. While the use of steel mill products allows designers to use standard mill products, based on precalculated load capacity listed in the building construction codes, custom components like castings are more difficult to design. The designer must determine what properties and quality measures to use in the analysis of the component's safety. Often the design is based on the minimum properties required in the specification with no given context for the actual distribution of properties for these type of products. Mechanical property allowances for design, which are statistically supported for steel castings are not available. Steel Founders' Society of America (SFSA) has collected the ordinary testing results for commercial carbon steel heats from a variety of producers, in order to develop an extensive data set of properties. This data set has been analyzed and is compared to steel mill properties, specifications, and allowable design values, which are embedded in the American Institute of Steel Construction-Specification for Structural Steel Buildings (AISC-ASD), and the ASME Boiler and Pressure Vessel Code (ASME BPVC). This analysis demonstrates the capability of carbon steel castings to provide safe and reliable service that is compatible with steel mill products in fabrications or other structures. Statistically supported values for tensile properties for steel castings are reported and compared with other steel products. Significant findings show: (1) Carbon steel castings have properties compatible to other product forms such as forgings and mill products. (2) Carbon steel components meet the design allowables included in the ASME BPVC and AISC-ASD requirements with similar properties to other structural steels. (3) The use of net-effective area and a fraction of the UTS for allowable stress design by AISC is comparable to the challenge of creating thick-section complex-geometric design of steel castings. (4) The proposed limit for design, based on the ratio of yield strength to ultimate tensile strength (YS/UTS) provides a reasonable guide for safe and reliable design for steel castings as well as structural steel shapes. (5) The proposed quality index (QI) for steel casting provides satisfactory guidance for the lower bound of commercial cast alloys at 280 ksi. This is also the common upper level of specification requirements. [ABSTRACT FROM AUTHOR]

Strand surface defects originate from the initial solidification of molten steel in continuous casting mold. This article investigates the initial solidification behavior during the continuous casting of 55SiCr spring steel billet using a novel mold simulator. First, the high‐frequency responding temperatures and high‐frequency heat fluxes across the mold corner and hot face are calculated by the 2D‐inverse heat conduction program mathematical model and the fast Fourier transformation, and the results indicate that the temperature variations and heat flux fluctuations around mold corner are stronger than those at mold hot face. Then, the characteristic heat fluxes around the meniscus at mold corner and hot face are analyzed, and their four corresponding signals are discussed with the help of power spectral density analysis. The average solidification factor K for shell corner is greater than shell face, which indicates that the cooling intensity of shell at corner is stronger due to the two‐dimensional heat transfer near mold corner, as demonstrated by heat transfer and dendrite structure analysis. Finally, the interrelations between the shell profile, mold oscillation, heat flux change rate, high‐frequency heat flux, temperature change rate, and high‐frequency temperature for the two cases are discussed. [ABSTRACT FROM AUTHOR]

The aim of the work was to obtain advanced oxide materials, obtained through technologies compatible with sustainable development materials. These materials are used in special operating conditions, such as in the case of continuous steel casting, where there is a temperature difference of over 10000C between the mold wall and the steel crust. These are the lubricating powders for the crystallizer. [ABSTRACT FROM AUTHOR]

Direct measurement of the wetting angles of the mold fluxes is a strenuous work and time-consuming, and a mathematical model relating the wetting angle of mold flux to its chemical composition is rarely found up to now. In this work, multiple linear regression (MLR), backpropagation neural network (BPNN), and GA-BP neural network (GA-BPNN) are used to model and predict the wetting angle of mold flux. Results show that the accuracy of MLR, BPNN, and GA-BPNN model is 76, 62, and 83 pct; the GA-BPNN model has the highest prediction accuracy. In addition, according to the standardized coefficients in the MLR model, the influence degree of different chemical components on the wetting angle of mold fluxes is analyzed. The importance of the influence of various components on the wetting angle is Fe2O3, F−, Li2O, Na2O, R, MnO, Al2O3, B2O3, and MgO from high to low. Among them, Fe2O3, Li2O, Na2O, R, and MnO have a negative effect on the wetting angle of mold flux, while F−, Al2O3, B2O3, and MgO have a positive effect. The established GA-BPNN model could facilitate the design and optimization of mold slag in the steel continuous casting process. [ABSTRACT FROM AUTHOR]

Thin slab casting and rolling (TSCR) is a near-net-shape manufacturing process and a key development technology in China's iron and steel industry. This study uses cross-scale calculations to analyze the complete process of thin slab casting. The focus is on simulating and predicting the final solidification structure by adjusting process parameters. The aim is to enable further investigation into material performance and establish a foundation for researching deformation and phase transformation. To achieve this, a coupled model has been developed to simulate the entire thin slab casting process, using hot stamping steel as the research subject. The model encompasses fluid flow, heat transfer, and solidification. The study identifies the optimal combination for flow field, temperature distribution, and equiaxed grain ratio within the specified parameter range at a casting speed of 4.0 m/min and a superheat of 40 °C. The aim of the study is to establish an integrated computational materials engineering (ICME) research system for near-net-shape automotive steel casting processes. [ABSTRACT FROM AUTHOR]

In the current study, the quantity, size, and spatial distribution of non-metallic inclusions along the thickness direction of an ultralow carbon IF steel were detected employing an automatic SEM-EDS scanning system. And the distribution of the slab subsurface inclusions was mainly analyzed. In addition, the total oxygen content in the steel and the solidification structure of the slab were analyzed. Upon the application of M-EMS, the solidification front was flushed due to the stirring effect generated by the electromagnetic force, promoting the floating removal of inclusions, thereby improving the overall cleanliness of the slab. However, the probability of the collision and agglomeration of inclusions was increased by applying M-EMS, resulting in an increase in the size of inclusions. The influence of M-EMS on inclusions was primarily on the slab subsurface. Following the application of M-EMS, the inclusions in the slab subsurface were experienced a reduction in number density from 9.99 to 6.11 #/mm2, and the area fraction was decreased from 69.51 × 10−6 to 57.31 × 10−6. However, the average size of inclusions was increased from 2.45 to 2.87 μm. With the application of M-EMS, the total oxygen content in the subsurface of the slab was reduced by 1–3 ppm, and the total oxygen content in the center of the slab was reduced by 0–1 ppm. These results indicated that the adoption of M-EMS contributed positively to the reduction of inclusions from the slab subsurface, thereby enhancing the surface quality of the slabs. Furthermore, the analysis revealed that the equiaxed crystal area comprised 12.06 pct of the total area without the consideration of M-EMS, while with the application of M-EMS, this proportion increased to 20.99 pct. [ABSTRACT FROM AUTHOR]

This paper presents the results of research from the renovation of functional parts of crane wheel surfaces. The aim of the research was to verify the possibilities of changing the chemical composition of the additive materials for submerged arc cladding, in order to increase the resistance of the wheel surfaces to wear. The base material of the crane wheel was heat-treated carbon steel for castings, mat. no. 1.0553. The renovation process was carried out on three equal wheels. Conventionally used additive material, the same one used for the interlayer and two covering layers, was used on one wheel. On two other wheels, newly increased tubular wires with a higher proportion of carbide-forming additives (Cr, Mo) were used for the carbide coating of two covering layers, in addition to their conventional additive material. Low-alloy additive material was applied to the newly elevated wires. The quality of the clads was assessed using non-destructive tests. Subsequently, microstructural analysis was carried out on the test samples taken from the renovated wheels, by means of light microscopy. On the cross cuttings, the course of hardness was evaluated using Vickers analysis. The resistance of functional surfaces to adhesion wear was evaluated based on weight losses measured using the AMSler experimental equipment. The results of the experiments showed an increase in the tribological resistance of the surfaces, specifically by 45% due to the newly developed wire C1 and by 18% due to wire B1, and it is therefore possible to recommend renovation. [ABSTRACT FROM AUTHOR]

This study investigates a new insulating refractory material based on rice husk ashes (RHA) for its application in the steel ingot casting process. The excellent insulating properties of this material may improve heat- and energy balance during ingot casting. A flame-sprayed alumina coating is applied to provide chemical inertness of the substrate material against the steel melt. The refractoriness, oxidation resistance, phase evolution and thermal expansion of four different grades of RHA materials and phase evolution and thermal expansion of flame-sprayed alumina coatings are studied. The refractoriness of the RHA materials increased with increasing silica content, showing sufficient refractoriness up to 1600 °C for SiO 2 > 94 wt%. Immersion tests with composite materials made from RHA substrate and a flame-sprayed alumina coating were successfully performed in a steel casting simulator. No deformation of the substrate material nor spalling of the flame-sprayed alumina coating was observed despite an immersion without preheating. [ABSTRACT FROM AUTHOR]

In the course of the decarbonization of steel production, electric steel production will continue to gain importance. The processing of low‐quality scrap will also play an important role, which may lead to an increase in the content of so‐called tramp elements in steel production and further processing. This article examines the effect of the elements Cu, Sn, and Ni on the formation of surface cracks under the conditions of the continuous casting process. Results of an in situ bending test are compared with the results of the experimental simulation of high‐temperature oxidation and thermodynamic analysis based on the CALculation of PHase Diagrams (CALPHAD) approach. For a temperature of 900 °C, an equivalent Cu content of 0.20 wt% must be considered as the critical upper limit. The presumable reason is the existence of Cu‐ and Sn‐rich liquid phases at the austenite grain boundaries. The results clearly show the effect of the investigated elements but also point to the importance of the gas atmosphere and cooling conditions on the results. This can be a groundbreaking result for extending the process window for casting steels with increased tramp element contents. [ABSTRACT FROM AUTHOR]

A steel belt casting equipment, weighing approximately ∼6–7 tons and measuring ∼5 m in length, has been designed and developed for simulating the industrial processing of polymer films and being combined with synchrotron radiation in situ x-ray scattering measurements. Through modification of its modules, it is feasible to implement two distinct film casting modes, namely the wet and the dry casting processes. The speed of a steel belt can span from 0.5 to 8 m/min. The highest experimental temperature and drying wind speed are 300 °C and 6 m/s, respectively. All film casting parameters, such as extrusion speed, distance between die and steel belt, casting speed, temperature, and wind speed, can be adjusted independently. Especially, the control accuracy of the temperature and casting rate can reach ±0.1 °C and ±0.01 m/min, respectively. The feasibility of this equipment has been validated through in situ x-ray scattering tests at the BL10U1 industrial beamline of the Shanghai synchrotron radiation facility. With the assistance of this equipment, the understanding of the physical mechanism behind the film casting process should be improved so that the development of advanced functional polymer films. [ABSTRACT FROM AUTHOR]

Laser beam remelting is a relatively simple and highly effective technique for the physical modification of surfaces to improve resistance to cavitation erosion. In this study, we investigated the effect of laser remelting on the surface of cast stainless steel with 0.40% C, 25% Cr, 20% Ni, and 1.5% Si on cavitation erosion behavior in tap water. The investigation was conducted using a piezoceramic crystal vibrator apparatus. Base laser beam parameters were carefully selected to result in a defect-free surface (no porosity, material burn, cracks) with hardness capable of generating better resistance to cavitation erosion. The experimental results were compared with those of the reference material. Surface morphology and microstructure evolution after cavitation tests were analyzed using an optical metallographic microscope (OM), scanning electron microscope (SEM), and hardness tests to explore the mechanism of improving surface degradation resistance. The conducted research demonstrated that surfaces modified by laser remelting exhibit a 4.8–5.1 times greater increase in cavitation erosion resistance due to the homogenization of chemical composition and refinement of the microstructure, while maintaining the properties of the base material. [ABSTRACT FROM AUTHOR]

To improve shear capacity, as well as reduce on-site casting and steel consumption, a novel Y-shaped perfobond rib (Y-PBL) shear connector with ultra-high-performance concrete (UHPC) grout was proposed. The shear behavior of the Y-PBL shear connector was investigated by six groups of pushout specimens. Their failure modes, load–slip curves, load–separation curves, strain analysis, and shear transfer mechanisms were discussed. Subsequently, finite-element analysis (FEA) models were established to study the effect of parameters on the shear behavior of the Y-PBL shear connector, as well as to compare the shear capacity contributions with straight-shaped PBL (S-PBL) shear connectors. Analytical models were proposed to predict the shear capacity of the Y-PBL shear connector. The results reveal that the proposed Y-PBL shear connector has superior shear capacity and stiffness. The contribution of the perforating rebar is minor compared with the end-bearing effect of UHPC. The analytical predictions agree well with the experimental and FEA results. This study can be used to guide the design and application of the Y-PBL shear connector in steel-concrete composite bridges. [ABSTRACT FROM AUTHOR]

Pittsburgh's Carnegie Institute was founded by the Scottish-born steel magnate Andrew Carnegie in 1895 and held the only annual art exhibitions in the United States open to artists from overseas. Prominent British artists Augustus John, Laura Knight, A. J. Munnings, and William Nicholson all served on the jury of award for the Carnegie's annual exhibitions in successive years, from 1921 to 1924. The bilateral relations between the United Kingdom and the US were sometimes strained during the 1920s. In comparison, the prominence of British art remained strong. While the influence of France in early twentieth century Anglo-American art has been well established, this article encourages an examination of the direct transatlantic links between the UK and the US. [ABSTRACT FROM AUTHOR]

The characteristics, formation mechanism, and removal of large‐sized CaO–Al2O3–SiO2 inclusions in D2 high‐speed railway wheel steel are investigated. Large‐sized CaO–Al2O3–SiO2 inclusions are present in the continuous casting billet, with SiO2 and CaO content ranging from 5 to 15 and 30 to 65 wt%, respectively. The size mainly exceeds 10 μm. These inclusions originate from the calcium‐treatment stage of the refining process, during which liquid CaO–Al2O3–SiO2 inclusions are formed in the liquid steel. The contact angle between these inclusions and the liquid steel is below 40°, which results in excellent wettability. Consequently, the inclusions are difficult to remove from the liquid steel and are thus inherited into the billet. By reducing the SiO2 content and controlling CaO content between 8 and 30 wt%, small‐sized inclusions are formed. This requires reasonable control of the Al and Ca content in the liquid steel. When the Al and Ca content in liquid steel is maintained at 0.012 wt% and 8 ppm, respectively, the inclusions in the billet are mainly CaO·6Al2O3 (CA6) and CaO·2Al2O3 (CA2), both under 5 μm in size. These inclusions represent the suitable inclusions in steel. [ABSTRACT FROM AUTHOR]

The production of high‐carbon hard wire steel at high speeds necessitates the use of appropriate technical support to ensure cost‐efficiency and optimal performance of the special steel casting machine. This study investigates the industrial application of single‐roller hard reduction technology in a domestic steel plant for the production of high‐carbon hard wire steel billets, specifically of section 165 × 165 mm. The produced billets meet all customer specifications and demonstrate the benefits of this approach, including lower comprehensive costs, suitability for modification, and advanced technical concepts. These features make this method compatible with a wide range of billet casting machines, from standard to specialized. In this research, discussion is done on the reduction process, the layout of withdrawal and straightening units (WSUs), and the optimal casting speed. It is concluded that bow‐type billet casting machines using rigid dummy bars can achieve single‐roller hard reduction by only three WSUs, offering lower comprehensive costs and suitability for modification. This approach is particularly beneficial for small billet casting machines undergoing an upgrade from general to high‐quality and ultimately to special steel. During the process of increasing the central density of the billet and improving central defects using single‐roller hard reduction technology, it is observed that defects in the central region gravitated toward the center. For billet casting machines with a bow radius of 10 m, considering process tolerance, the maximum casting speeds achievable with single‐roller hard reduction are 2.95–3.40 m min−1 for a section of 150 × 150 mm, 2.60–3.0 m min−1 for a section of 160 × 160 mm, and 2.45–2.80 m min−1 for a section of 165 × 165 mm. To achieve higher casting speeds for high‐carbon hard wire steel, it is necessary to modify the machine configuration to flexible dummy bars. [ABSTRACT FROM AUTHOR]

In the current study, the influence of TiO 2 /SiO 2 and BaO/CaO ratios on viscosity, crystallization and structure of high-TiO 2 mold slags was discussed through the measurement of viscosity-temperature relationship, melting temperature, crystallization temperature, crystallization rate and phases, and Raman spectrum. With the substitution of SiO 2 by TiO 2 in slags from 0 % to 12 %, the viscosity at 1300 °C, the melting temperature and break temperature decreased and then increased, while those of slags with the substitution of CaO by BaO from 4 % to 16 % decreased. With the substitution of SiO 2 by TiO 2 from 0 % to 10 %, crystallization phases gradually changed from cuspidine (Ca 4 Si 2 F 2 O 7) to perovskite (CaTiO 3), the initial and complete crystallization temperatures had the tendency to increase from 918 °C to 1260 °C and from 857 °C to 1139 °C, respectively, and the overall crystallization ability of slags increased. With the substitution of CaO by BaO from 4 % to 16 %, the initial and complete crystallization temperature of these slags decreased, and the overall crystalline ability decreased. With the substitution of SiO 2 by TiO 2 from 0 % to 10 %, structural units changed from the simple units to complex units, but the transition was opposite with the substitution from 10 % to 12 %, which was related to the transition of TiO 2 from basic oxide to amphoteric oxide. With the substitution of CaO by BaO from 4 % to 16 %, the degree of polymerization and the viscosity of theses slags decreased, which was related to the supplement of more active O2− ion from BaO. Hence, the excessive substitution of SiO 2 by TiO 2 under the steel-slag reaction would cause the increase of the slag viscosity and crystallization ability, while the substitution of CaO by BaO could weaken the variation of slag viscosity and crystallization ability. [ABSTRACT FROM AUTHOR]

Carbon-based materials (e.g., carbon/carbon [C/C] and carbon/carbon-silicon carbide [C/C-SiC] materials) are considered promising brake disk materials for high-speed trains to replace cast or forged steels. Investigating the braking behavior of copper-based composites paired with various counterpart materials is helpful in advancing the development of high-speed and lightweight brake systems. In this study, the braking behavior and wear mechanisms of a novel copper-based composite mated with cast steel, C/C and C/C-SiC materials were investigated. The average coefficients of friction for the copper-based composite against C/C and C/C-SiC materials are increased by approximately 16.5% and 6.7%, and the wear rates of the copper-based composite against C/C and C/C-SiC materials are reduced by about 25.9% and 33.9% in comparison to those of the copper-based composite against cast steel. Additionally, compared with that of cast steel, the wear rate of the C/C material is increased by more than 3 times, and the negative value of the wear rate of the C/C-SiC material is noted. The dominant wear mechanisms of the copper-based composite mated with cast steel, C/C and C/C-SiC materials are adhesive wear combined with oxidation, graphite loss combined with oxidation as well as exfoliation of the material near graphite, and the material transfer combined with oxidation, respectively. [ABSTRACT FROM AUTHOR]

The mold electromagnetic stirring technology and mold feeding steel strip technology are both effective method of reducing center segregation and shrinkage cavities in continuous casting bloom. In this work, a bidirectional flow-solid coupling model was established to investigate the swing and depth of steel strip feeding with the influence of both molten steel and electromagnetic forces. The results indicate that increasing the strip's feeding speed from 0.2 to 0.4 m/s without electromagnetic stirring results in an increase in the swinging amplitude from 6.26 to 11.89 mm. With the implementation of mold electromagnetic stirring, the bottom of the steel strip moves on the "Z" shape periodically, and the swing amplitude increasing with the current strength rising. When the feeding speeds are 0.2, 0.3, and 0.4 m/s, and the current is increased from 200 to 300 A, the maximum swing amplitude of the steel strip increases from 7.30, 12.18, and 21.09 to 10.34, 19.47, and 41.14 mm, respectively. [ABSTRACT FROM AUTHOR]

A new two-way coupled magnetohydrodynamic (MHD) model considering the dynamics change of electromagnetic force at steel–slag interface was established to investigate the multiphase flow and slag entrapment in slab continuous casting under mold electromagnetic stirring (EMS). The transient turbulent flow and the steel–slag interface behavior were described by solving the large eddy simulation (LES) model and volume of fluid (VOF) model. The level fluctuation, the location, and net mass of slag entrapment were quantitatively evaluated. By comparing the predicted level height within the in-situ measurement, the results show that the two-way coupled MHD model can better reveal the multiphase flow under EMS. The type of slag entrapment is closely related to the flow pattern, the vortex formation is predominant under the lower EMS current, while it changes to the shear-layer instability under the relatively high EMS current, the proportion of vortex formation slag entrapment decreases to 30.7 pct under the EMS current is 600 A. The tendency of net slag entrapment rate is the same as that of level fluctuation, with the increase of EMS current and casting speed, both the level height and net slag entrapment rate decrease firstly and then increase. Therefore, it is necessary to match the casting speed and EMS current to avoid the slag entrapment in actual production. The net slag entrapment rate is 0.034 kg/s, under the condition of 1.2 m/min casting speed and 600 A EMS current. [ABSTRACT FROM AUTHOR]

Longitudinal crack defects are a frequent occurrence on the surface of thin slabs during the high-speed continuous casting process. Therefore, this study undertakes a detailed analysis of the solidification characteristics of hyper-peritectic steel thin slabs. By establishing a three-dimensional heat transfer numerical model of the thin slab, the formation mechanism of longitudinal cracks caused by uneven growth of the initial shell is determined. Based on the mechanism of longitudinal crack formation, by adjusting the performance parameters of the mold flux, the contradiction between the heat transfer control and lubrication improvement of the mold flux is fully coordinated, further reducing the incidence of longitudinal cracks on the surface of the casting thin slab. The results show that, using the optimized mold flux, the basicity increases from 1.60 to 1.68, the F- mass fraction increases from 10.67% to 11.22%, the Na2O mass fraction increases from 4.35% to 5.28%, the Li2O mass fraction increases from 0.68% to 0.75%, and the carbon mass fraction reduces from 10.86% to 10.47%. The crystallization performance and rheological properties of the mold flux significantly improve, reducing the heat transfer performance while ensuring the lubrication ability of the molten slag. After optimizing the mold flux, a surface detection system was used to statistically analyze the longitudinal cracks on the surface of the casting thin slab. The proportion of longitudinal cracks (crack length/steel coil length, where each coil produced is about 32 m long) on the surface of the thin slab decreases from 0.056% to 0.031%, and the surface quality of the thin slab significantly improves. [ABSTRACT FROM AUTHOR]

Steel-making and continuous casting (SCC) processes are considered the main bottlenecks in the steel industry. We consider planning and scheduling problems in SCC processes and provide an overview of the literature with our commentary. The planning problem has as goal to create out of customer orders production units for the various production processes. The scheduling problem assigns these production units to the production facilities over different time intervals. We review a large number of planning and scheduling papers and propose two basic models for the planning and the scheduling problems that incorporate the most common and essential features. We describe for each problem the respective constraints and objectives as well as the practical implications in an actual production environment. We also analyse the methodologies used in their solutions, including decomposition strategies. In the last section, we present the conclusions of our survey and propose new research directions. [ABSTRACT FROM AUTHOR]

In this paper, issues related to the technology of compound castings composed of two parts, i.e., the working layer and the supporting part, made of X46Cr13 high-chromium steel and EN-GJL-HB 255 grey cast iron, respectively, in a liquid–solid system by pre-installing a monolithic insert in the mould cavity are presented. As a part of the research, the mechanism of formation of transitional zones in the bonding area of the above-mentioned two alloys was identified and described. It was shown that the phenomenon that determines the formation of a permanent bond between the joined materials is the transport of C and heat from the "high-carbon and hot" material of the supporting part poured into the mould in the form of liquid cast iron to the "low-carbon and cold" material of the working layer placed in the form of a steel monolithic insert inside the mould cavity. In the paper, the suitability of the compound castings technology developed for use in the coke industry is also presented. Full-size high-chromium steel–grey cast iron compound casting plates designed for the coke quenching car lining were positively verified in real coke plant operating conditions. [ABSTRACT FROM AUTHOR]

Introduction: As an economical and fast process method for surface modification of materials, overlay welding is increasingly widely used in the manufacturing and repair of parts in various industrial sectors. Methods: This study combines grating projection measurement to design an economical mold arc additive process, and introduces point cloud simplification algorithm for wear and repair design of the mold structure. Then, a new method for manufacturing low-cost, long-life, and economical hot stamping die inserts is designed, using low-cost forged steel and cast steel as substrates and surface welding of high-temperature alloy wear-resistant layers. Results and Discussion: The experiment shows that the proposed algorithm for simplifying scattered molds has a good evaluation effect, without any gaps, and has a good retention effect on point clouds. The maximum and minimum distances are 0.45mm and 0.025 mm, respectively. The friction coefficient of cobalt based alloys at 300°C is lower than that at 200°C, and the fluctuation period at 200°C is significantly longer than that at 300°C. HSTS steel has the highest wear resistance, and the performance of cobalt-based alloys is significantly better than that of other alloys. The compressive yield strength of iron-based alloys is the highest, and the hardness of iron-based alloys is the highest, at 53.2 HRC. Therefore, iron-based alloys were selected as a surface wear-resistant layer welding material for economical molds with cooling channels, and cobalt-based alloys were also selected as a surface wearresistant layer welding material for variable strength economical molds. The research results provide a reference for economic mold manufacturing and repair. [ABSTRACT FROM AUTHOR]

Graphite spheroids are one of the most intriguing forms of aggregation of graphite. They can be found as natural graphite in meteorites and volcanic rocks (metamorphic graphite caused by exposure to heat and pressure in the earth's crust), and in man-made materials such as steel and cast iron, but also in pyrolytic graphite, in carbon nanosheets obtained through vapor deposition, and others. While growth of graphite has been studied in depth during the last decades, the understanding of its physics continues to evolve as modern investigating equipment pushes the knowledge horizon. The complexities of the solidification of cast iron and its dependency on undercooling, a function of the cooling rate and of the nucleation potential, are discussed in conjunction with the asymmetric eutectic coupled zone. A sequential chart summarizes the various stages of graphite aggregation, as the graphite begins growing in contact with the nucleus at the beginning of solidification till it reaches its final crystallography at room temperature. It sets the basis for an in-depth analysis of the multi-mechanisms involved in the growth of graphite in cast iron during solidification and the subsequent solid-state transformation, with emphasis on compacted and spheroidal graphite. It discusses the significance of turbostratic graphite that appears mostly, but not only, at the nucleus/graphite interface and in the initial stages of graphitization, as revealed by recent electron microscopy studies. [ABSTRACT FROM AUTHOR]

The influence of laser-alloyed stainless steel coatings on the properties of the surfaces of cast iron discs, such as friction-induced vibration and noise, friction coefficient, residual stress, hardness, and corrosion resistance, was investigated in this study. The experimental results show that after laser alloying, the surface hardness of the cast iron discs increased significantly. The residual stresses on the surfaces of the laser-alloyed discs changed from tensile to compressive residual stresses, while any compressive residual stresses increased by more than six times. Most of the laser-alloyed discs demonstrated better performance in friction-induced vibration and noise damping and friction reduction. Metallographic observation and XRD (X-ray diffraction) analysis results show that the laser-alloyed layer is mainly a mixture of acicular martensite and dendritic material, while the phase composition of laser-treated discs is mainly martensitic, [Fe, Ni], Fe3Si, Cr23C6, and austenite, which plays a significant role in the improvement of the properties of the laser-alloyed cast iron in physics, tribology and corrosion resistance. This research has significance for the laser surface treatment of various cast irons and steels, which is an increasingly important manufacturing technology in the vehicle friction brake industry. [ABSTRACT FROM AUTHOR]

ŠTORE STEEL Ltd. is one of the three steel plants in Slovenia. Continuous cast 180 mm × 180 mm billets can undergo cooling to room temperature using a turnover cooling bed. They can also be cooled down under hoods or heat treated to reduce residual stresses. Additional operations of heat treatment from 36 h up to 72 h and cooling of the billets for 24 h, with limited capacities (with only two heat treatment furnaces and only six hoods), drastically influence productivity. Accordingly, the casting must be carefully planned (i.e., the main thing is casting in sequences), while the internal quality of the billets (i.e., the occurrence of inner defects) may be compromised. Also, the stock of billets can increase dramatically. As a result, it was necessary to consider the abandoning of cooling under hoods and heat treatment of billets. Based on the collected scrap data after ultrasonic examination of rolled bars, linear regression and genetic programming were used for prediction of the occurrence of inner defects. Based on modeling results, cooling under hoods and heat treatment of billets were abandoned at the casting of several steel grades. Accordingly, the casting sequences increased, and the stock of billets decreased drastically while the internal quality of the rolled bars remained the same. [ABSTRACT FROM AUTHOR]

The study investigates the effect of pulsed magnetic fields on undissolved carbides in high-carbon chromium bearing steel GCr15 billets. The billets were subjected to heat treatment at 950 °C, with a pulsed magnetic field of varying durations applied during the process. The influence of the pulsed magnetic field on the distribution of undissolved carbides within the billets was investigated, and the thermodynamic and kinetic mechanisms of undissolved carbides dissolution were explored. The results indicate that the area percentage of undissolved carbides in the microstructure decreases from 1.68% to 0.06% after applying a pulsed magnetic field for 10 min, and the size of undissolved carbides decreases from 17.5 μm to 4.9 μm. When a pulsed magnetic field is applied for 30 min, all undissolved carbides dissolve. The statistics demonstrate that the average size of undissolved carbides is reduced from 14.19 μm to 0.63 μm, with a reduction percentage reaching 96%. Over the same duration, the number density of the undissolved carbides decreases from (0.19~0.55)/mm2 to (0.03~0.1)/mm2, and the percentage area of the undissolved carbides decreases from (1.26~1.68)% to (0~0.02)%. Thermodynamically, applying a pulsed magnetic field lowers the dissolution energy barrier of undissolved carbides and modifies their transformation temperature. Kinetically, the rate of alloy element diffusion is enhanced by increasing the frequency of atomic jumps. This research aims to provide new insights into enhancing the contact fatigue life of bearing steel, increasing the proportion of special steel, and optimizing the steel deep-processing process. [ABSTRACT FROM AUTHOR]

The corrosion resistance of bearing materials is crucial for the long-term service and high precision of modern equipment, and has aroused widespread research interest. Inoculation treatment is beneficial for improving the mechanical properties of GCr15 bearing steel, but its impact on corrosion behavior remains to be investigated. In the present work, the influence of inoculation treatment on the corrosion morphology, open circuit potential, impedance spectrum, and polarization curve evolution of GCr15 steel was studied through in situ corrosion morphology analysis and electrochemical testing. The results showed that the samples treated after inoculation showed a reduced tendency for pitting corrosion and an obviously improved corrosion resistance. This improvement is related to the transformation of columnar grains into equiaxed grains during the inoculation process, which reduces the amount and distribution of inclusions and pores, thereby delaying the rapid development of pitting corrosion. This study provides new insights into the corrosion mechanism of gestational steel. [ABSTRACT FROM AUTHOR]

The object of research is the technology of manufacturing «Body»-type shaped castings of the from medium carbon steel in one-time sand molds. The existing problem is that the design of the casting and foundry equipment significantly affect the formation of internal defects in castings. This especially applies to steel castings, the technology of which is more complicated than the technology of cast iron castings due to much worse casting properties of steel. To determine the influence of the location of surpluses on the «Body»-type steel castings of the on the formation of shrinkage shells, computer modeling was used, in the process of which 5 computer experiments were conducted with different sizes and geometries of surpluses. According to the simulation results, it was found that with some technological options, there is a risk of the shrinkage shell penetrating into the casting body. The use of a cylindrical surplus of a rectangular cross-section with fillets ensures complete absorption of the shrink shell in the place of surplus installation. Using an excess round section at the installation location does not guarantee absorption of the shrink shell. The determining factor affecting the coefficient of increase in the depth of the shrinking shell is the excess volume. This influence can be described by a functional dependence of the logarithmic type with the coefficient of determination R2 = 0.82. It was determined that the ratio of the diameter of the inlet to its height does not affect the coefficient of increase in the depth of the shrinking shell. The resulting functional dependence allows to set the excess volume that provides a minimum growth factor while simultaneously preventing excess metal consumption. The presented study will be useful for machine-building enterprises that have foundries in their structure, where shaped castings are made in one-time sand molds. [ABSTRACT FROM AUTHOR]

The article compares the efficiency of technologies for feeding liquid metal into the mold of a continuous casting machine (CCM) and its flow within the mold volume under conditions of free and forced mixing. The influence of various designs of the developed mixing devices on the nature of the melt flow in the mold volume is analyzed. The objects of research are the hydrodynamic and thermal flows of liquid metal during the casting of steel into the CCM mold. [ABSTRACT FROM AUTHOR]

Herein, the effects of the bottom shape of the submerged entry nozzle (SEN) on the molten steel flow and size distribution of argon bubbles are analyzed in a steel continuous casting slab strand using multiple‐size‐group approach. The type of nozzle bottom includes the well bottom, flat bottom, and mountain bottom. Most of argon bubbles are larger than 4.5 mm inside the SEN and the mold at the three types of nozzles. The frequency distribution of bubbles inside the SEN increases from 28.29% to 32.65% and 35.74% for 5.0–5.5 mm bubbles and decreases from 53.71–50.49% and 47.38% for 5.5–6.0 mm bubbles with the nozzle bottom varied from the flat to mountain and well shape, respectively. The number density of argon bubbles with 4.0–5.5 mm diameter in the mold decreases and increases for 5.5–6.0 mm bubbles with the nozzle bottom varying from the well to flat and mountain shape, respectively. In addition, the results of the industrial trials show that inclusions adhesion and aggregation at the bottom of the nozzle are eliminated using the flat bottom SEN casting. Meanwhile, the mechanism of SEN clogging under the different types of nozzle bottoms is analyzed. [ABSTRACT FROM AUTHOR]

In the current study, the influence of Li2O and Na2O on the viscosity, crystallization, and structure of the high TiO2-containing mold slag for the continuous casting of high-Ti steel was investigated to improve the property of the CaO–SiO2–TiO2-based slag under the steel-slag reaction through the measurement of the viscosity-temperature relationship, crystallization temperature and phases, and the Raman spectrum. With the increase of Li2O content from 0 to 8 pct, the viscosity at 1300 °C and melting temperature decreased from 0.54 to 0.01 Pa s, and 1151 to 884 °C, respectively. While the viscosity of the slag at 1300 °C increased from 0.20 to 0.62 Pa s, the viscosity of the slag at 1400 °C decreased from 0.16 to 0.09 Pa s, and the melting temperature decreased from 1195 to 1077 °C with the Na2O content from 2 to 10 pct. According to the thermodynamic calculation and XRD measurement, the main crystallization phase of high TiO2 slags was CaTiO3 with the content of Li2O below 4 pct and Na2O of 2 to 10 pct, the crystallization phase gradually changed from CaTiO3 to LiTiO2 with Li2O from 4 to 8 pct, and the morphology of the crystalline nucleus changed from the type of spiky star to barbed sphere. Similarly, with the Li2O content from 2 to 6 pct the initial and complete crystallization temperature decreased and increased, respectively, while those increased with the increase of Na2O content, indicating that the increase of the Li2O below 4 pct and the decrease of the Na2O in the current slag resulted in the weak crystallization ability. With the addition of Li2O content, the complex structural units of Q1, Q2 and Q3 were depolymerized, and the slag viscosity decreased. With the increase of Na2O content, structural units of Q0, Q1 and Q2 structure units had the tendency to increase, and the viscosity of slag at 1400 °C decreased. These results could be used for the selection of typical components of mold slags for continuous casting of high-Ti steel. [ABSTRACT FROM AUTHOR]

During production, significant differences were observed between the center and surface composition of the transition bloom, posing challenges in accurately determining its location. To address this issue, we developed a three-dimensional (3D) multiphysics coupled numerical simulation of the steel grade transition. This simulation is based on fluid–solid–thermal–magnetic and solute transportation models, encompassing the entire process from the ladle nozzle to the solidification endpoint. In contrast to prior studies that treated new and old grades as distinct components, our approach regards each element as an individual component, enabling the investigation of the specific segregation behavior of each element. By simultaneously accounting for the effects of flow and segregation on the composition of the transition bloom, our proposed model offers a clear understanding of the distribution of solute elements within the bloom. Moreover, our model exhibits higher prediction accuracy compared to previous approaches used for steel grade transitions. The research findings indicate that assigning a steel grade with higher density and lower solute element content as the old grade, and a steel grade with lower density and higher solute element content as the new grade, results in a transition bloom length of 24.70 m. Conversely, when the casting sequence is reversed, the length of the transition bloom increases to 33.44 m. Therefore, our new model provides a theoretical basis for reducing the length of the transition bloom. By implementing a well-planned casting sequence for the steel grade transition, substantial reductions in the length of the transition bloom can be achieved, leading to significant cost savings in production. [ABSTRACT FROM AUTHOR]

Reoxidation during secondary refining and casting of liquid steel can seriously deteriorate both process stability and the quality control of the final steel product. Unfortunately, detecting reoxidation occurrences is a formidable challenge until process troubles are encountered or product quality issues arise. In the present study, an energy dispersive spectrometer (EDS) was employed to analyze the composition of non-metallic inclusions in Al-killed steel. The specific focus was on deciphering whether the Fe signal within the EDS data originated from the steel (Fe) matrix or from FetO in the inclusions. It was revealed that when reoxidation levels are low, the primary source of the Fe signal is the steel matrix. Conversely, when reoxidation levels are high, a portion of the Fe signal can indeed be attributed to FetO in the inclusions, representing a mixture of signals from the steel matrix and oxide inclusions. A novel method for presenting EDS data was proposed to facilitate the identification of whether the inclusion comprises FetO to some extent. This distinction is critical in assessing whether the liquid steel has undergone reoxidation. To validate the present EDS analysis, a series of Monte Carlo simulations was conducted. It confirmed that EDS analysis of inclusions in steel specimens can effectively signal the presence of reoxidation. This research provides valuable insights for process control and quality assurance in steel production, helping to mitigate the detrimental effects of reoxidation. [ABSTRACT FROM AUTHOR]

The solidification process of castings is prone to shrinkage porosity and macroscopic segregation defects. Utilizing a reduction technique to control the defects in the solidification process of castings is an effective method. In order to investigate the influence mechanism of reduction technology on the reduction-induced deformation at different positions during the solidification process of castings and the impact on the density of solidification structure, laboratory experiments on the reduction-induced deformation of steel ingots during solidification were conducted. Corresponding finite element numerical simulations were performed, and micro-CT detection was employed to analyze the pore distribution of the ingots. It was found that reduction-induced deformation during the solidification can effectively enhance the density of steel ingots. This study also innovatively introduces the concept of relative deformation displacement and reduction-induced deformation transfer coefficient, providing a measure of the actual compression deformation at different positions in the steel ingot during the reduction-induced deformation process. When the fraction solid is less than 0.70, the reduction-induced deformation transfer coefficient is ranging between 1.1 and 1.2. However, when the fraction solid is greater than 0.75, the reduction-induced deformation transfer coefficient rapidly decreases with an increase in the fraction solid until it reaches zero. [ABSTRACT FROM AUTHOR]

This article investigated the influence of copper (Cu) and nickel (Ni) on atmospheric corrosion in gray cast iron under simulated marine conditions. The goal was to compare the effect of Cu and Ni addition in castings with weathering steels. Selected alloys were cast, cut, prepared, and heat-treated for microstructure homogenization. Accelerated corrosion tests were conducted using a salt spray chamber. Corroded samples were analyzed for corrosion thickness and deposits using scanning electron microscopy, X-ray diffraction, and electrochemical techniques. The results indicate that alloying elements significantly affect corrosion processes. In the long-term, Cu had a greater impact on the corrosion mechanisms than Ni. Both Cu and Ni exhibited similar effects on the corrosion mechanisms in gray cast iron and weathering steels. In the initial and final stages, the behavior was comparable to that of weathering steels, but in the intermediate stage, it differed from the literature, suggesting the presence of an additional mechanism between these stages. [ABSTRACT FROM AUTHOR]

Previous studies have demonstrated that the response of stable yielding systems to random excitations such as earthquakes is inherently accompanied by residual deformations. Stable yielding systems with highly enhanced ductility capacity are more prone to residual deformations. Steel eccentrically braced frames (EBFs) are designed to sustain significant localized inelastic deformations in the segment of the beam referred to as the yielding link, which results in much larger link rotations when compared to inter‐story drift ratios (SDR). Recent experimental and numerical studies on the response of EBFs have demonstrated that even with moderate residual inter‐SDR (less than 0.5%), severe link residual rotations could be expected, which could render the structure difficult to repair. For replaceable yielding links, which were developed to expedite the repair and recovery process in EBFs after major seismic events, large residual link rotations will hinder the link replacement process or at times make it impossible. Therefore, mitigation of residual deformations is of greater importance in EBFs with replaceable yielding links than in conventional EBFs with a continuous beam. This paper provides a brief review of past research on residual deformations and methods for their mitigation. A low‐cost re‐centering system for use in EBFs is proposed to work in parallel with the yielding link, in order to mitigate residual deformations. The proposed system is adopted for two prototype structures designed with EBFs equipped with cast steel replaceable modular yielding links. The effectiveness of the re‐centering strategy is evaluated by means of pseudo‐dynamic hybrid simulations, as well as numerical simulations. The hybrid simulations and numerical studies both demonstrate that not only the proposed system is highly effective at mitigating the residual deformations, but also it is effective in reducing the peak deformations in EBFs. [ABSTRACT FROM AUTHOR]