Casting Plant Research Articles

Ecotoxicological assessment of waste foundry sands and the application of different classification systems.

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;00:1-18. © 2024 The Author(s). Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Innovative machine learning based approach for reliable and accurate measurement of guide roll alignment in continuous casting plants

Continuous casting (strand casting) is the leading-edge technology in modern steel production. Even slight improvements of the casting process offer a range of benefits, such as improved quality, higher productivity, energy savings and a reduced environmental impact. The precise alignment of a plants guiding rolls is a crucial factor for its performance. Strand condition monitoring systems usually incorporate modules to gauge the alignment of the guiding rolls. These modules measure the angle formed by two successive rolls by using metal rulers fitted with inclination sensors. However, the angle of the ruler only represents a valid measurement where it maintains firm contact with two successive rolls. Most of these systems rely on inductive switches that trigger a measurement at these locations. Yet this approach provides unreliable results due to the trigger’s insufficient accuracy. Furthermore, this method stores only one data point per roll, which is problematic due to significant measurement noise. Apparently, a reliable and accurate alignment measurement remains a significant challenge. As part of an ongoing research project, this paper presents the development of a novel alignment measurement module. The module will provide continuous readings from the inclination sensors without the need for a trigger. In addition, an innovative machine learning based approach to distinguish between valid and invalid measurements is developed. This method enables the averaging of multiple measurements per roll, drastically reducing the impact of measurement noise while providing reliable alignment angles. To overcome the limited availability of real-world data, which is insufficient for model training, the measurement module is simulated to generate artificial training data. Our machine learning model achieves excellent performance on this artificially generated dataset. The paper concludes by outlining how the new approach will be applied to real-world data generated by the new module

IMPROVEMENT OF CONSTRUCTION FITTINGS PRODUCTION TECHNOLOGY AS A STEP IN THE DEVELOPMENT OF CLEANER PRODUCTION

This study is devoted to the topic of environmental problems arising in the process of production of reinforcement building materials and the possibility of reducing the environmental burden on the environment through the introduction of improved technology for the production of structural reinforcement. The authors substantiate the need to improve production technology, present a modern method and technology aimed not only at reducing emissions into the environment, but also improving the quality of the products obtained, which is another step towards the development of environmentally friendly production. In the proposed technology, liquid metal in a furnace is fed to a single-head casting plant, intermediate heating during the production of fittings is eliminated, which leads to environmental and production benefits, which will also be described in the article. The study is of practical interest to manufacturers of building reinforcement, as well as to specialists in the field of ecology and economics, who are involved in reducing the harmful impact on the environment and optimizing production costs. Keywords: building fittings, production, technology, ecology, pollution, waste, environmentally friendly production, energy saving, quality, cost optimization.

Application of thermal analysis in ferrous and nonferrous foundries

This paper is devoted to the memory of Professor Ljubomir Nedeljkovic (1933-2020), Head of the Department of Iron and Steel Metallurgy University of Belgrade, Serbia. Assessment of the melt quality is one of the most important casting process parameters, which allowed sound production of intricated cast parts. At the present time, various devices have been applied at foundry floors to control melt quality. Thermal analysis is one of them, widely used for melt quality control in ferrous and non-ferrous casting plants. During solidification, metal and alloys released latent heat, which magnitude is dependent on the type of phases that form during the solidification process. Plotting temperature versus time data during solidification provides useful information related to the actual solidification process. The applied technique is called thermal analysis, whereas the cooling curve is the name of such a plot. The main aim of this paper is to give a short overview of the present thermal analysis application in various foundries and to indicate the future potential use of this technique.

Mathematical model of heating system before the melting of the metal suspension upper half in the manufacture of turbine blades GTE

The article presents the developed mathematical model of heating system before the upper half of the metal suspension melting during the technological process of manufacturing the turbine blades in a discrete-continuous casting plant. The relevance of this research is connected with the lack of reliable mathematical model that can predict the distribution of temperature fields and heat flows inside the plant, which have a direct impact on the quality of formed macro - and microstructure in the castings of turbine blades. The currently existing methods of indirect indicators’ estimation carry significant errors in the selection of optimal technological modes of the blade casting process. The developed model makes it possible to predict more accurate the distribution of temperature fields and heat fluxes in the corresponding zones of the casting plant. Thanks to this, it is possible to predict with maximum accuracy the production of blades with a given internal structure, as well as to estimate the amount of volumetric shrinkage and deformation of the casting. The developed mathematical model in production conditions will make it possible to predict casting defects in the form of captivity and failure, reduce labor capacity and increase the productivity of the blade casting process.

To the Question of the Manufacturing Ability a Contact Wire by Continuous Casting Rod

The article presents the results of pilot-industrial experiments in the field of manufacturing technology of contact wire made of Cu-Sn alloys. Cast rods with a diameter of 20 mm, made of CuSn0.04, CuSn0.1, CuSn0.2, CuSn0.3, CuSn0.4 alloys, were obtained in a continuous casting plant on an Upcast system. Cast rods were deformed using a Conform technology, and extruded billets with a diameter of 18 and 20 mm were produced, which were subsequently drawn on a shaped contact wire with a cross section of 100 mm2. Cast rods macrostructure and microstructure were studied. The macrostructure quantitative assessment of samples was studied in a cross and longitudinal section. A plot of the effect of the tin content in the alloy on the average grain area in cross section is obtained. An increase in the tin content in the alloy leads to a decrease in the average grain area. An analysis of the rod microstructure in a cross section showed that the structure is a grain of an α-solid solution of tin in copper, and the grain boundaries are thin and clean. After deformation by Conform technology a uniform fine-grained structure is ensured. The effect of the tin content in the alloy on the Brinell hardness of cast billets, made by Conform technology, is determined. An increase in the tin content in the alloy leads to an increase in the hardness of both cast and deformed billets. The microstructure analysis of the contact wire in the cross section is carried out. The mechanical and electrical properties of the contact wire with a cross section of 100 mm2 are determined. An analysis of the results showed when the tin content in the alloy is up to 0.4 wt. %, the required level of mechanical and electrical properties of the contact wire is not provided. It may be necessary to change the size of the initial billet before drawing or to increase the tin content in the alloy more than 0.4 wt. %.

Quality Function Deployment for Quality Performance Analysis in Indonesian Automotive Company for Engine Manufacturing

The research aimed to improve the quality problem from the previous plant that contributed to the Rate of Quality (RQ) and Overall Equipment Effectiveness (OEE) value in Cylinder Block Machining (CBM). The research was done in one of an automotive company in Indonesia. It had been applying Total Productive Maintenance (TPM) with Kaizen spirit to make continuous improvement even though this company had reached a world-class level on the Japan Institute of Plant Maintenance (JIPM) standard. To express the needs and wants of the current machining plant and improve quality problems from the previous process in the casting plant, the researchers used Quality Function Deployment (QFD) method. From the result, it is known that shrinkage defect at a casting product becomes the priority of the kaizen team to achieve next process customer satisfaction in a machining plant to increase the RQ and OEE value. By implementing improvement based on the highest value of Technical Priorities (TP) from House of Quality (HOQ), it can increase RQ value in CBM from 96,4% in December 2018 to 97,9% in February 2019. Then, OEE value increases from 92% to 93% within two months.

Improving apportionment of PM2.5 using multisite PMF by constraining G-values with a prioriinformation

Rotational ambiguity in factor analyses prevents users from obtaining accurate source apportionment results. The rotational space in positive matrix factorization (PMF) can be reduced by constraining the solution with a prioriinformation such as source profiles. However, the only prior report on constraints using information on the source contributions was their use to ensure compatibility in the simultaneous analyses of PM2.5 and PM10 data. By combining data from three monitoring sites affected by a gear casting plant in Xi'an as an example, a methodology for improving the accuracy of PMF results by constraining source contributions using wind information was explored. Seven common factors derived from individual PMF analyses for each of the three sites (INDUS, URBAN, and RURAL) with different location characteristics, were then combined in a multisite PMF analysis. The factors were interpreted as nitrate with all site average contributions of 28.7%, sulfate (22.5%), coal combustion (19.3%), road traffic (12.8%), biomass burning (6.4%), soil (5.4%), and metallurgical industry (4.9%). Except for the INDUS site, contributions of metallurgical industry to the URBAN and RURAL sites were pulled down maximally to reduce the rotational space. The constrained solution substantially improved the results over the base run. The local and regional nature of the sources were identified by coefficient of divergence combined with Pearson correlation analysis, and further quantitatively estimated using Lenschow approach. On average, local sources contributed for 52.4% and 47.7% of the PM2.5 mass concentrations at the INDUS and URBAN site respectively. The metallurgical industry showed the highest local contributions while sulfate was primarily regional. For the multisite analysis where there are considerable point source emissions, this methodology highlights the role of local wind directions to inform constraints on the results and obtaining more reliable solutions.

Environmental Assessment of the Toxic Effect of Slagheap on Soil Continuum

This article shows the study of the toxicological state of soils in the areas of anthropogenic impact of slag dump industrial waste of aluminum casting in the Oryol region. The data obtained indicate a high impact of slag dumps as a result of waste storage in the production of aluminum casting [3]. The inter-elemental relationship between the studied toxic metals shows that heavy metals can also have the same anthropogenic origin, regardless of the sources of their origin. The results of the pollution index prove the moderately high level of pollution of the study areas. A comprehensive assessment of the degree of degradation of light gray forest soils and their ecological resistance to natural processes and regimes, anthropogenic loads occurring in the soil profile [5] is shown. Analysis of the isotopic composition of heavy metals proves their obvious anthropogenic origin, including industrial emissions from an aluminum casting plant, exhaust gases derived from regular exposure to vehicles, as well as from dust storms. Studies are made of the effect of slag dumps on the environment, in particular, the effect on soil, water and plant cover. As a result of the research performed, the local impact of the slag dump on the adjacent territory and its pollution with a complex of heavy metals were revealed.

Experimental study on accelerometer-based ladle slag detection in continuous casting process

The share of continuous casting method is increased day by day among steel production methods. In continuous casting plants, steel production is carried out using BOF (basic oxygen furnace) or EAF (electric arc furnace). During the journey of the liquid steel through whole steelmaking stages, the carryover ladle slag can turn into one of the most detrimental element in casters. It is known that a carryover ladle slag consists of mainly oxides such as CaO, SiO2, Al2O3, and MgO. Carryover slag has to be kept under control otherwise one can end up with negative results. With the development of sensor technology, the detection of carryover ladle slag becomes possible at the end of heats. The main advantage of the sensor type is early detection over a human-controlled system. A few seconds can make a big difference on safety, quality, yield, castability, and cost when the casting sequence lengthens due to the amount of slag. Nowadays, steel production via BOF which is performed with very low profit margins makes it important to solve this problem. Especially steelmaking produced by BOF, the detection methods of carryover slag are human controlled, electromagnetic based, ultrasonic based, image processing based, acoustic based, and vibration based. In this study, it is seen that the vibration-based detection system has many advantages over others when considering investment cost, product quality, castability, and accuracy. The scope of the study aimed to design a vibration-based carryover slag detection system on BOF steel production line. The designed detection system has an accelerometer, data processor, and controller system. After the experimental study, the cost, the product quality, and the productivity analyses were performed for the condition of use and non-use of the vibration-based detection system. At the end of this study, it is seen that the vibration-based carryover slag detection system is affordable and feasible.

Restoration by electric arc surfacing of rollers made of 24CrMo1V installed on secondary cooling system by continuous casting plant

The study is devoted to the selection of surfacing materials for manufacturing and (or) reconstruction electric arc surfacing of rollers of the secondary cooling system of steel continuous casting plant made of 24CrMo1V steel in order to increase their service life.

Experimental Investigation of the Influence of a Centered Line Sparger on the Jet from the Shroud in a 1:3 Water Model of a Tundish

In a continuous casting plant a tundish serves two main purposes. Firstly, it is a buffer vessel between the ladles and the mold and secondly, it is designed to remove non‐metallic particles from the melt. As the demands on the quality of the cast product have increased strongly, floatation (removal of particles using bubbles) of the particles becomes necessary. These bubbles alter the global flow field in the tundish. At large gas flow rates this influence needs to be considered in the positioning of mechanical flow control devices such as wears or impact pads. In this paper the influence of a line sparger on the global flow field is investigated using a 1:3 water model. A series of PIV (Particle Image Velocimetry) measurements have been performed at a wide range of air and water flow rates showing the influence of the bubbles on the shape of the liquid jet from the shroud. In addition, a dimensionless number is derived, which can be used to scale the gas flow rate from different experiments. This number is shown to be valid within the range of the experiments presented in this paper.

Моделирование процесса неизотермического отверждения термопластичного шликера BeO в кольцевом канале установки литья

Моделирование процесса неизотермического отверждения термопластичного шликера BeO в кольцевом канале установки литья

Adaptive Control of Meniscus Velocity in Continuous Caster based on NARX Neural Network Model

Meniscus velocity in continuous casting is critical in determining the quality of the steel. Due to the complex nature of the various interacting phenomena in the process, designing model-based controllers can prove to be a challenge. In this paper a NARX neural network model is trained to describe the complex relationship between the applied current to an Electromagnetic Brake (EMBr) and the measured meniscus velocity. The data for the model is obtained using a laboratory scale continuous casting plant. Adaptive Model Predictive Control (MPC) was used to deal with the non-linearity of the model by adapting the prediction model to the different operating conditions. The controller uses the EMBr as an actuator to keep the meniscus velocity within the optimum range, and reject disturbances that occur during the casting process such as changing the casting speed.

Control of Jet Flow Angle in Continuous Casting Process using an Electromagnetic Brake

Abstract The flow pattern in the mould of the continuous casting is an important factor in determining the quality of the steel slabs that are produced in the end of the process. Hence it can heavily influence manufacturing costs due to the scrap percentage. Electromagnetic actuators are frequently used in the continuous casting process to stabilize the flow in the mould and therefore produce higher quality of steel slabs. Usually they are used in open loop but their effect on the flow pattern may be much better directed if they are used as a part of closed loop control based on real time measurements. In this paper, a closed loop controller is proposed that adjusts the magnetic field of an electromagnetic brake using the real time measurement of the angle of the jet flowing from the Submerged Entry Nozzle (SEN). The angle is kept within a specific range by the controller in order to prevent a deeper jet impingement into the mould; this allows us to achieve the desirable double roll flow pattern, and to avoid the entrapment of slug. The controller is based on a model of the relationship between brake current and jet angle that was obtained using experimental data from a laboratory scale continuous casting plant.

METHODOLOGY OF ASSESSING INDIVIDUAL RELIABILITY OF UNIQUE STRUCTURES

The paper describes the author’s methodology of quantitative reliability assessment of unique systems that are components of very expensive critical/strategic infrastructures, manufactured in very small series/batches, or even as single, unique structures. It was dubbed “theory of individual structural reliability — TISR”. With the development of the 3D digital technology and digitization that opened the door to creating digital twins in design, the share of unique products is growing non-stop in all branches of contemporary heavy industry and machine-building (rotor excavators, continuous casting plants, drilling rigs), adjacent sectors of industry (ship-building, aircraft building), and construction industry (large span bridges, super high skyscrapers, exhibition pavilions etc.). In this paper the TISR methodology is described for a class of unique and non-renewable objects using as an example a one-time-deployed-when-on-orbit robotic technological complex, designed to serve without interruption for 12–15 years in the near-space environment. The paper is a direct extract from preprint [1], revised and translated into English by its first author. The initial data needed for writing paragraphs 4 and 6 of this paper belongs to Yu. P. Pokhabov, published elsewhere, which made the description of implementing the TISR methodology in the field of unique spacecraft design up to date. The author greatly appreciates and acknowledges the provided input.

Improving Decision-Making Grid based on interdependence among failures with a case study in the steel industry

Purpose Decision-Making Grid (DMG) is used for determining maintenance tactics and is associated with the reliability and risk management of assets. In this grid, decision making is performed based on two indicators of Mean Time to Repair (MTTR) and frequency of failures. The purpose of this paper is to improve DMG by recognizing interdependence among failures. Design/methodology/approach Fault Tree Analysis and Reliability Block Diagram have been applied for improving DMG. The proposed approach has been examined on eight equipment of the steel making and continuous casting plant of Mobarakeh Steel Company. Findings Findings indicate different positions of equipment in the cells of the new grid compared to the basic grid. Research limitations/implications DMG is limited to two criteria of frequency of failures and MTTR values. In both basic and new DMGs, cost analysis has not been performed. The application of the proposed approach will help the reliability/maintenance engineers/analysts/managers to allocate more suitable maintenance tactics to equipment. This, in turn, will enhance the equipment life cycle and availability as the main objectives of physical asset management. Originality/value A major limitation of basic DMG is that the determined tactic based on these two indicators might not be an appropriate solution in all conditions, particularly when failures are interdependent. This has been resolved in this paper.

On the damage mechanisms in a continuous casting mold: After-service material characterization and finite element simulation

Abstract A mold is a part of a continuous casting plant where the molten steel starts to solidify. The inner surface of the mold undergoes a cyclic thermal load. In fact, service conditions are characterized by a high thermal flux, which vanishes when the plant is switched off. The highest temperatures occur in the area just beneath the free level of liquid steel (meniscus). The same area is typically characterized by thermal fatigue cracks when the mold is inspected after service. This work presents the characterization of the material of a copper mold after it had been used in the plant. The aim was to understand the damage and cracking mechanism, and our analysis confirmed that a network of cracks was present on the inner mold surface in the meniscus area, which experienced the maximum temperature gradients. Metallurgical examination demonstrated the transgranular characteristics of cracks, thus suggesting that thermal fatigue was the main cause of the damage observed. The location of the thermal fatigue cracks corresponded to the area experiencing the highest levels of plastic strains, as confirmed by the results of a finite element analysis simulating the mold in-service conditions.

Demand-side management via optimal production scheduling in power-intensive industries: The case of metal casting process

The increasing challenges to the grid stability posed by the penetration of renewable energy resources urge a more active role for demand response programs as viable alternatives to a further expansion of peak power generators. This work presents a methodology to exploit the demand flexibility of energy-intensive industries under Demand-Side Management programs in the energy and reserve markets. To this end, we propose a novel scheduling model for a multi-stage multi-line process, which incorporates both the critical manufacturing constraints and the technical requirements imposed by the market. Using mixed integer programming approach, two optimization problems are formulated to sequentially minimize the cost in a day-ahead energy market and maximize the reserve provision when participating in the ancillary market. The effectiveness of day-ahead scheduling model has been verified for the case of a real metal casting plant in the Nordic market, where a significant reduction of energy cost is obtained. Furthermore, the reserve provision is shown to be a potential tool for capitalizing on the reserve market as a secondary revenue stream.

Metallurgical and surface damage analysis in a copper mold after service

In continuous casting plants, the mold is the component where the molten steel starts to solidify. Being exposed to a high and time-varying thermal flux, the mold after service is typically characterized by thermal fatigue cracks on its inner surface. With the aim to get insights into the damage and cracking mechanism, this work undertakes a failure and metallurgical analysis of a copper mold after service. The analysis indicates that transgranular cracks are mainly located in the area just below the meniscus and they are typical of thermal fatigue. This hypothesis is also supported by finite element results, which confirm high levels of strain in the area where cracks appear