Johann Winkler, K1-MET GmbH, Austria

Co-Author:
Susanne Hahn, Primetals Technologies Austria
Sergiu Ilie, voestalpine Stahl GmbH
Christian Bernhard, Montanuniversität Leoben
Roman Krobath, voestalpine Wire Rod Austria GmbH

Abstract:
The in-situ bending test IMC-B provides the characterization of the crack sensitivity of steel after controlled solidification and subsequent cooling. The present study investigates the influence of varying cooling conditions on the surface defect sensitivity of low and medium carbon steel with 0.02-0.04 wt.-% Nb. Standard cooling as well as “soft cooling” and “hard cooling” strategies for slab casting are investigated. The results indicate a significantly higher crack sensitivity for hard cooling than the soft cooling strategy. The simulation of the corner temperature history also considerably shifts the ductility trough towards lower temperatures. The findings confirm the experience of slab casting operation. Finally, the bending test results and grain size measurement are applied for benchmarking the recently developed commercial defect monitoring tool for continuous casting, SQI. The results point to excellent correspondence and show the high potential of smart online quality prediction based on thermodynamics and process data for the future.

Matthias Taferner, Montanuniversität Leoben, Austria

Co-Author:
Daniel Kavic, Montanuniversität Leoben
Michael Bernhard, Montanuniversität Leoben
Julian Laschinger, K1-MET GmbH
Sergiu Ilie, voestalpine Stahl GmbH
Christian Bernhard, Montanuniversität Leoben
Michael Bernhard, Montanuniversität Leoben

Abstract:
Secondary cooling of the strand is one of the key issues in achieving the demanded surface quality in casting defect-sensitive steel grades. Numerous laboratory setups characterize heat transfer coefficients (HTC) between the air-mist cooling sprays and the strand surface. The recently developed nozzle measuring stand (NMS) at “Montanuniversitaet Leoben” provides the measurement of water distribution, impact pressure and local heat transfer coefficients for a wide variety of spray parameters. The quantification of these parameters in the overlap region between two sprays is a unique feature. The embedment of the NMS into an in-house developed 2D-FV-solidification simulation software called m²CAST provides the direct transformation of the measurements via a neural network-based HTC database towards surface temperature control in continuous casting (CC). The presentation will exemplify the influence of cooling parameters on the water distribution, impact pressure and local HTC. The spraying parameters include the distance between the nozzle and strand surface, the inter-distance of nozzles, the water flow rate, and air pressure. All these parameters may have a significant impact on the spray characteristics and the local strand surface temperature. The presentation will also connect this information with considerations of strand surface quality, including defect sensitivity, microstructural parameters and internal oxidation phenomena.

Ji Joon Kim, POSCO, Korea, Republic of

Co-Author:
Young-Wook Jun, AIcraft Inc.
Jong-Chul Kim, POSCO

Abstract:
Reducing the slab width widening around the 400 series stainless steel is very necessary to improve the yield rate by reducing the amount of slab edge in the hot rolled coil. The amount of slab edge is multiple linear defects that occur within 20mm of both edges of the coil due to the widening of the slab narrow side during rough rolling of hot-rolling. In this study, a factory applied on-line model for the development of an artificial intelligence (AI)-based slab width prediction model is proposed. The proposed model collects operation data in units of 1 second during continuous casting and includes everything from the data preprocessing process to the learning and evaluation of the artificial intelligence model. A multilayer perceptron (MLP) model was used. The most important thing in the data pre-processing process is to align the working data by the position of the width of the slab. The developed width control model shows more than 95% of slab width prediction accuracy for both the learning data and the evaluation data. It is expected that the research model proposed in this study can be applied to the development of various predictive models with time series characteristics.

Riccardo Bono, Università degli Studi di Milano, Italy

Co-Author:
Marco Alloni, Prosimet S.p.A.
Riccardo Carli, Prosimet S.p.A.
Monica Dapiaggi, Università degli studi di Milano
Camilla Giada Baroni, Università degli studi di Milano
Andrea Bernasconi, Università degli Studi di Torino

Abstract:
The change in structure in casting powders as a function of their basicity is well known to have important effects on their rheology, and therefore on their success in casting. Different compositions of casting powders were prepared in the form of glasses, by melting the appropriate mixture and fast quenching. The structure of the glasses was studied by means of neutron total scattering at the spallation neutron source ISIS (UK), at the beamline NIMROD [1]. Even though amorphous materials do not possess a long range order, they do have a short range order, whose variations may be responsible for the change in properties. The total scattering data were corrected for all the scattering not produced by the sample and Fourier transformed into a Pair Distribution Function, which provides peaks in correspondence of interatomic bonds. The figure shows an example for 4 of the samples, with a different fluorine content: sample 10 has the highest fluorine content, while sample 11 has the lowest. The shoulder in the plot, at about 2.3 Å, corresponds to the Ca-F bond length. The data were analysed through the software EPSR (Empirical Potential Structure Refinement) [2], which allows the creation of a 3D model of the system under study. From the model, various geometrical and structural information can be gained, such as the distribution of coordination numbers, bond lengths and bond angles. This allows to fully understand the subtle differences in the local structure of the glasses, and therefore to produce casting powders with a better performance. References [1] https://www.isis.stfc.ac.uk/Pages/nimrod.aspx [2] Soper AK (2010) EPSRshell: a users guide. ISIS DisorderedMaterial Group, Didcot

Mirko Javurek, Johannes Kepler University, Austria

Co-Author:
Sergiu Ilje, voestalpine Stahl GmbH

Abstract:
In bow-type continuous slab casters, non metallic macro-inclusions (size 50 to 200 μm) are concentrated in a small band over the strand thickness, also called „quarter depth inclusion band“. This effect was observed in measurements and can be explained theoretically by the bow geometry in combination with the upwards drift velocity of inclusions in the liquid steel due to the density difference. Measurements also showed that the inclusion distribution is often significantly inhomogeneous and asymmetric over the strand width. Theoretical considerations explain this effect by an inhomogeneous flow pattern in the bending zone of the strand. In this contribution, transient numerical flow simulations of the liquid steel inside of the strand with the scale resolving SAS turbulence model in combination with non-metallic particle transport are presented. The time scales of the flow fluctuations in the bending zone showed to be quite large. Therefore, one hour of the casting process was simulated, which requires about one year of computation time. Two cases without and with argon gas injection at the stopper rod tip were considered. The injected gas is assumed to form bubbles, that are transported with the liquid steel flow into the mold and influence the mold flow by their buoyancy forces. The results show irregular fluctuations of the inclusion distribution with alternating asymmetric profiles over the strand width, with time scales in the order of magnitude of several minutes, corresponding to strand length distances of several meters. The case with argon injections shows slightly lower peak concentrations than the case without gas injection.

Bahareh Najafian Ashrafi, K1-MET GmbH, Austria

Co-Author:
Alija Vila, Primetals Technologies Austria
Felix Lindbauer, Primetals Technologies Austria
Martin Barna, Johannes Kepler University

Abstract:
Continuous casting is the main method of steel production, with over 96 percent worldwide. Thus, optimizing this process can heavily impact the steel manufacturing costs. The application of electromagnetic fields in the continuous casting of slabs is a well-known method to control the flow field inside the cast strand. If applied properly, electromagnetic fields can result in an improved flow behaviour, consequently, minimizing the product defects. Electromagnetic fields are divided into two major categories: static and traveling magnetic fields. Electromagnetic Braking (EMBr) systems use static magnetic fields to stabilize the flow, especially in high casting speed situations. To control the molten steel flow more actively, travelling magnetic field systems with their greater capability to impact the steel flow were developed. Three different moving fields can be generated: Electromagnetic Level Stabilizer (EMLS), Electromagnetic Level Accelerator (EMLA), and Electromagnetic Rotating Stirrer (EMRS). Depending on the flow situation in the mould region, and the need for acceleration, deceleration, or stirring, each of these modes can be activated. Any combination of these traveling magnetic fields with static magnetic field is also possible. Although this combination makes the flow field much more complex, it provides the simultaneous flow control in the whole mould region (both above and below the submerged jets). The impact of EMRS without and with EMBR (combined mode) on the mould flow pattern were investigated in the current work. The results show that the surface velocities can be homogenized and increased due to EMRS. The combination with EMBr can cause homogenized surface velocities and reduced jet penetration length.

Qifeng Shu, University of Oulu, Finland

Co-Author:
Timo Fabritius, University of Oulu
Tuomas Alatarvas, University of Oulu

Abstract:
Non-metallic inclusions have critical effects on the properties and manufacturing process of steels. The amount, composition, morphology and size distribution of inclusions define the cleanliness of steel, which is the key to “clean steel”. In this work, a modelling framework for describing the evolution of amount, composition and size distribution of inclusions during refining and casting is established based on the thermodynamic-kinetic models and nucleation models. In order to calculate the evolution of size distribution of inclusions, the nucleation, growth and coarsening of inclusions are described by Kampmann-Wagner numerical model and the collisions and agglomerations are modelled by the population balance model. Both homogeneous and heterogeneous nucleation are accounted for. The model can be also employed to describe the evolution of inclusions during cooling and solidification by combining a solidification model. The models have been validated using both laboratory- and process-scale experimental data for aluminum deoxidation, reoxidation and inclusion precipitation during solidification. It is found that the supersaturation is the key for determining the dominant nucleation. During the inclusion precipitation with a high concentration of deoxidizing elements, e.g. Al, the homogeneous nucleation is dominant. In comparison, the heterogeneous nucleation and following diffusion is the most probable way to modify alumina into spinel and solid and liquid calcium aluminates. The present modelling framework will make it possible to calculate the evolution of amount, composition and size distribution inclusions during the whole process chain in steelmaking and casting, and therefore provide a valuable tool for process control in steel plants. Owing to the wide range of applicable cooling rates, the model is applicable not only for slabs but also for blooms, billets or thin slabs.

Maria Thumfart, K1-MET GmbH, Austria

Co-Author:
Christine Gruber, K1-MET GmbH
Johann Wachlmayr, K1-MET GmbH
Roman Rössler, voestalpine AG

Abstract:
In the upcoming years, the steel industry faces major challenges due to the demands of CO2 reduction and a shift towards circular economy. These developments lead to a larger diversity in crude steel compositions and thus to increased demands for secondary metallurgy including the RHplant. To meet these increased demands the efficiency of the RH process needs to be improved. Such an improvement can be based on better process understanding, enhanced process models and improved measurement data. The results presented in this paper target the improvement of the process understanding by providing advanced analysis of high-quality images of the melt surface in the chamber. These images show a complex two-phase flow situation ranging from highly dynamic steel foam to the generation of small drops. Different situations can be linked to different process conditions. During oxygen blowing the generation of small drops is more likely, while during calmer degassing steps a coarse steel foam layer of significant thickness can be observed, emitting singular or lumps of liquid steel bubbles completely detached from the melt surface. In addition to these phase distribution phenomena a pulsating behaviour of the melt can be identified during foamy states showing regular eruptions. This dominant frequency has been detected based on the velocity of the visible objects in the chamber. These observations provide the basis for better process understanding and better process monitoring. The presence of a foam layer implies that the interfacial area between gas and liquid is much larger than expected while the dominant frequency of the velocity evaluation might be used to validate simulation models for the two-phase flow in the chamber. The visible difference between the different states in the chamber can be exploited for video-based process monitoring. These findings are a first step towards improving the RH process and its reliability.

Claire Dwyer, Tata Steel Ltd , Netherlands

Co-Author:
Manuel Atienzo, Tata Steel Ltd
Robert-Jan Pielkenrood, Tata Steel Ltd
Aart Overbosch, Tata Steel Ltd
Huijuan Ding, Tata Steel Ltd

Abstract:
The injection of gas through the porous plugs during ladle treatment is important for the homogenisation of both steel chemistry and temperature and is critical to ensure the production of high quality steel. It is important to monitor the stirring performance as it is difficult to visually observe by the operators, even with the help of the surveillance camera and there can be leakages in the system or blockages of the porous plugs that affect the operation. To be able to objectively assess the stirring of a ladle during treatment at Ladle Furnace 22, in the steel plant of Tata Steel IJmuiden, a uniaxial accelerometer was installed on the ladle transfer car. This data was then processed and wirelessly transmitted on a per second basis to both the production PLC and a historical storage server. This data was then modelled and the output was shown to the operators on a screen in the pulpit. There were many learnings throughout the implementation process. This paper will elaborate the experiences during the project and what was achieved. After a period of preparation, a setup was installed and commissioned successfully. Since implementation all ladles are objectively rated and with this proof of concept complete it can be rolled out to the second plug of the ladle and then to all the other ladle treatment stations.

Eunju Jeong, POSCO, Korea, Republic of

Abstract:
Recently, many steel companies has been developing technologies for the realization of SMART steel making process. POSCO is also highly interested in automation process using smart technology in each process field to realize the smart factory. Papers and patents on automation process easily searchable across countries, and commercial technology products are on sale. Most of the automatic refining technologies aim at the dynamic control linked to the real-time decarburization characteristics while the static control by statistics proceeds. In this paper, the refining automation system in the AOD process that is being carried out at POSCO is introduced. In general, control of Oxygen-Nitrogen(or Argon) blowing step, basic weight and input of raw materials and temperature measuring and sampling of sub-lance are all performed manually by operators in AOD. Although this works are carried out under the standard, there is an operating deviation due to human factors. Therefore, an automatic refining technique was developed to reduce these human deviation factors in this study. In this automatic refining system, the decarburization state in the vessel is tracked in real time using the off-gas analyzer, and the end point of the each decarburization step is determined according to the criteria set and the blowing step is switched automatically. The raw materials to be added in the AOD process in order to match the ingredients for the steel are set in advance before the operation. When the automation of blowing starts, the raw materials are automatically weighed and put into the vessel according to each blowing step. Sampling for temperature and component confirmation of molten steel is also automatically performed at the designated time. Through this automatic control technology, it is confirmed that the operation deviation and amount of oxygen consumption was reduced.

Johan Björkvall, Swerim AB, Sweden

Co-Author:
Dan Sandström, Swerim AB
Fredrik Sandin , Luleå University of Technology
Konstantinos Rigas, KTH Royal Institute of Technology
Jurki Pitkälä, Outokumpu Sweden AB
Niklas Grip , Luleå University of Technology
Nils Andersson , Swerim AB
Björn Glaser , KTH Royal Institute of Technology
Mikael Svensson , Uddeholms AB
Robert Vikman , Jernkontoret

Abstract:
Measurement of the vibrations from metallurgical processes may give an indirect description of the process performance, thereby providing means to improve the overall process control. This approach is applied to the gas stirring of a ladle during vacuum treatment and the AOD converter in the present work. Analysing the vibration signals is challenging when vibrations from other processes surrounding the ladle or converter may affect the measurements. Even do vibration measured on ladles and converters has been reported before, the installation of vibration sensors must be adapted to plant-specific conditions as the temperature of sensors’ mounting positions and surrounding processes create vibrations. Positions for mounting the accelerometer were found close enough to monitor the vibrations from the process but at the same time at a position where the heat from the steel melt did not overheat the sensors. The positions of the accelerometers did not negatively affect the logistic of the steel production or the regular working procedures at the steel plants. Different mathematical algorithms were used to evaluate the recorded signals as machine learning, wavelet transform and the commonly used Fourier change. A comparison of the results from these different algorithms with available process parameters shows that the vibrations of the process correlate to the process performance. The analysed results correlate to the regulated gas flow at the vacuum ladle treatment and deviations most likely caused by fewer working porous plugs. In the AOD converter, the refining steps may be followed as different vibration intensities.

Gibeom Kim, Pohang University of Science and Technology, Korea, Republic of

Co-Author:
Jinyoung Kim, Graduate Institute of Ferrous & Energy Materials Technology
Chang-Hee Yim, Graduate Institute of Ferrous & Energy Materials Technology
Woong-Hee Han, POSCO
Soo-Chang Kang, POSCO
Dae-Geun Hong, Graduate Institute of Ferrous & Energy Materials Technology

Abstract:
In order to improve the efficiency of the decarburization reaction and control the ingredient of molten steel in the Ruhrstahl Heraeus (RH) degassing process, it is necessary to maintain an appropriate vacuum level and keep the refractory in contact with the molten steel clean. However, the temperature difference between the molten steel and refractories causes the steel skull and the solidified slag to adhere to the refractory, affecting the steel component deviation and steel product quality. Due to the absence of a quantitative measurement method for the present amount of steel skull in the RH process, it is difficult to establish an accurate relationship between operation variables affecting the precise element component control of molten steel. In addition, this leads to operation that relies on know-how of individual operator during the RH process. In this study, the quantitative measurement and its evaluation of the steel skull were conducted for improving the temperature control and adjustment of molten steel component during the RH operation. The amount of steel skull was estimated using cross-section images of vacuum vessel before and after the RH operation plant. The correlation between quantitative amount of steel skull and actual RH operation data including variables such as steel component, temperature and time was analyzed statistically technique machine learning. The steel skull amount as a dependent variable was categorized, and the machine learning modelling using the Random Forest (RF) and the Extra Tress (ET) algorithms was performed using approximately 620 data of RH operation. The obtained results have been discussed in context of the knowledge of steel making metallurgy. Physicochemical analysis about the change in the amount of steel skull and correlation between RH operation variables revealed the effectiveness of the proposed machine learning approach.

Marco Knepper, Hüttenwerke Krupp Mannesmann GmbH, Germany

Co-Author:
Torsten Müller, Primetals Technologies Germany
Willi Bühler, Primetals Technologies Germany
Wolfgang Brett, Primetals Technologies Germany
Sebastian Schäfer, Hüttenwerke Krupp Mannesmann GmbH

Abstract:
"A high degree of automation combined with a respective safety standard, reliable and user-friendly operation and a compact design are the requirements for modern ladle furnaces to be implemented in existing converter plants and steel mills. Primetals Technologies has successfully implemented its proven ladle furnace technology in combination with complex and high customer requirements with limited space availability at the HKM converter plant in Duisburg. In HKM, the entire production line is operated and monitored from a central control room. For this reason, all necessary work and functions must be controlled and supervised remotely, such as temperature and sampling, ladle stirring, etc. The ladle furnace is equipped with state of the art camera systems, robotics, automatic stirring gas coupling and a semi-automatic quick exchange for stirring gas lances to reduce manual tasks to a minimum. These complex automation processes require proven sensor technology to ensure a high level of operational reliability in the harsh environment of a steelplant as well as a holistic approach to combining different automated functions. Both individual components and combined automated processes of several plant parts, including the sensors used, are presented. Remaining user activities are explained, and security-related topics such as access to restricted areas and monitoring of the facility are described. Finally, the experience and operational results after more than 2 years of operation are presented to show the impact of the integration of a ladle furnace into an existing BOF meltshop in regards to the metallurgical impact and consumptions."

Mir Ishfaq, Indian Institute of Technology Bombay, India

Co-Author:
Manish M Pande, Indian Institute of Technology Bombay

Abstract:
Insoluble oxygen constitutes a substantial portion of total oxygen in the Al-deoxidized steels. The concentration of dissolved oxygen increases as the Al concentration increases beyond a certain critical value. In some steel grades, Al requirement is much higher than that is required for deoxidation. In the present work, the insoluble oxygen in such high aluminum steels has been estimated and compared using two different techniques: (i) two stage heating method in inert gas fusion infrared absorptiometry to differentiate soluble oxygen and insoluble oxygen. In the stage I, the sample was first heated to a temperature of 1873 K to remove all the dissolved oxygen. SEM studies showed that alumina inclusions were still present and were not removed by carbothermic reduction after stage I. In stage II, the sample was heated to 2613 K at which the alumina inclusions (insoluble oxygen) were reduced by the graphite. (ii) A Scanning Electron Microscopy Automated Inclusion Analysis (SEM-AIA) was used to estimate the size and number of inclusions in the steel samples. The insoluble oxygen was estimated, by Area Fraction (AF) method from the SEM-AIA data.

Luísa Saisse de Melo, Ternium, Brazil

Co-Author:
Heber Gomes, Ternium
Bruno Suveges Cerchiari, Ternium

Abstract:
In the current study, different process conditions with and without Calcium were applied to compare and investigate the steel cleanliness in terms of composition, quantity and size of non-metallic inclusions during refining process and continuous casting. The study was conducted in two different production routes and inclusions were characterized through ASTM E45 and SEM/EDS after the steel lamination. It consists to evaluate inclusionary results for heats treated in AHF (Aluminium Heating Furnace – similar CAS-OB) with Ca and RH (Ruhrstahl Heraeus) degasser without Ca on different process parameters such as killing tapping practices, slags addition, sulfur content and homogenization time control in order to have the same castability, properties and application of the final product. The results showed that for Ca-treat steels in AHF process route, as expected, inclusions were mostly Ca-aluminates globular ones in bigger size than the ones found at RH process from which the best results showed smaller quantity of big inclusions, specially oxides.

Yeongjin Jun, Hanyang University, Korea, Republic of

Co-Author:
Sungjin Park, POSCO
Soochang Kang, POSCO
Joohyun Park, Hanyang University

Abstract:
According to the global carbon neutral policy, the hydrogen energy market is growing and interest in hydrogen fuel cells is growing too. For the fuel cell separator, the Ti-containing ferritic stainless steels are used due to their high corrosion resistance, electrical conductivity, and durability. In a conventional steelmaking process, final steel quality is mainly affected by continuous casting tundish operation. In particular, the refining of Ti-added ferrite stainless steel and the relevant cleanliness have been improved via vacuum-oxygen-decarburization (VOD) and ladle treatment (LT) processes. However, the reoxidation phenomena inevitably occur during melt transfer from ladle to continuous casting tundish, resulting in a loss of titanium yield in conjunction with a formation of reoxidative inclusions. Hence, the present works aims to systematically investigate the combinational effect of different tundish fluxes on the reoxidation behavior of Al-killed stainless steel melts containing Ti. Rice husk ash (RHA), MgO (M) powder, and CaO-Al2O3 (CA) based fluxes were used for the experiments. When the molten steel was covered by M+CA fluxes, the average size of inclusions decreased, and it was confirmed that most the of inclusions were liquid (Ti2O3-Cr2O3-Al2O3) system. On the other hand, when the RHA+CA fluxes were added, the average size of inclusion decreased, whereas total number of inclusions significantly increased due to a reoxidation reaction by SiO2 in RHA. When the M+RHA+CA combinative fluxes were added, the size of inclusion decreased, and the number of inclusions exhibited a value between the M+CA and RHA+CA conditions. Consequently, a decrease in total oxygen content was largest in M+CA flux combination experiment.

Andrew Richardson, Liberty Speciality Steels Ltd, United Kingdom

Co-Author:
Howard Watkins, Liberty Speciality Steels

Abstract:
Liberty Speciality Steels operates a Vacuum Induction Melting (VIM) facility to produce high-performance iron and nickel-based alloys for applications in the aerospace and auto-sport industries. The paper describes process development work designed to minimise the incidence of spout skull build-up, the accumulation of solidified metal within the crucible pouring spout during ingot casting. Skull build-up must be manually removed after pouring of the heat, which requires unnecessary breaking of the vacuum between melts and leads to operational delays. A bespoke thermal model has been developed to help identify potential root causes of spout skull formation. Model simulations with the initial VIM power profile (kW as a function of crucible tilt angle), indicated that the pour stream temperature can fall below the solidus towards the end of pouring resulting in skull build-up. A revised power profile was devised, with the aim of maintaining a constant pour stream temperature. It was recognised that this could impact the solidification dynamics in the ingot head and the formation of the shrinkage cavity. A series of casting-simulations was carried out using the Magmasoft 3D package to determine the sensitivity of shrinkage-cavity size and depth to final pour stream temperature. Simulations for a constant pour stream temperature indicated a small decrease in the extent of pipe-cavity compared with the cooling pour stream situation. Predicted changes to cavity depth for different power profiles were judged to be insignificant. Measurements of cavity depths from sectioned ingots showed close agreement with model predictions. Production trials were undertaken across a range of alloy grades, using various power profiles designed to maintain a more constant pour stream temperature. Significant reductions in the extent and frequency of skull accumulation in the pouring spout were achieved, with associated reductions in operational downtime.

Greg Sergiienko, DANIELI Engineering & Services GmbH, Austria

Co-Author:
Rollando Paolone, Danieli Corus B.V
Angelico Della Negra, Danieli Corus B.V
Claudio Tomat, Danieli Corus B.V
Matthias Knabl, DANIELI Engineering & Services GmbH

Abstract:
Revert of superalloy scrap from investment casting is one of the most vital objectives for investment casting companies. Yielding only 20-40 % and selling back now the remaining 60-80% of superalloys to the alloy suppliers as a scrap, investment casters could improve their economy by remelting their own high-quality well-controlled scrap into barsticks at their own VIM furnace. Investment casting VIMs are not optimally designed for this, and usually fully engaged with their own program. Big alloy VIMs could easily remelt the scrap but require foundry infrastructure and are often not affordable for investment casters. DANIELI group as a full line plant supplier in the metals sector has developed a special scrap remelting VIM furnace concept: a very short cycle time, IGBT or SCR power supply parameters and a crucible geometry optimal for un-bulky charge, easy and fast automated back-charging, easy cleaning and maintenance, robust and fast vacuum system, no shop cranes needed, no scrap crushing needed. A special focus was put on operator friendly design. This new furnace concept sets a new milestone in economic and environment-friendly recycling of the high-value raw materials used and processed in investment casting. The concept is applicable for 100-500 kg casting weight.