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By Franco Gandin

With increasing demands for highly performing and at the same time efficient and running-costs saving vacuum-degassing equipment, dry mechanical pumps have been confirmed a proper choice to completely fulfill the expectations of steel-making companies worldwide. Regarding the production of both special carbon steel and stainless steel grades, the usage of mentioned pumps allowed reaching simultaneous remarkable results from different viewpoints in various Danieli worldwide installations (treating up to 200 t of liquid steel). As a matter of fact, in front of the replacement of a widely spread and renowned technology such as steamejector pumps with the recently developed technology embodied by the dry mechanical pumps, well-established metallurgical performances in terms of carbonhydrogen- nitrogen-sulphur removal have been repeatedly attained while meeting at the same time the client’s expectations concerning, for example, running-costs and push-button availability. Additionally, thanks to the very flexible, modular, redundant and maintenance-friendly equipment design, random problems occurring to the singular mechanical pumps can be easily solved without affecting the VD-VOD plant availability and metallurgical performance. With a particular regard to the VOD process, a very short overall process-time has been repeatedly performed (averagely less than 58min under-vacuum time at ChMP1) while guaranteeing the expected required quality of the final refined stainless steel. Moreover, in several VOD installations (ranging from 6 t up to 110 t of liquid steel) an efficient automatic process control such as dynamic pressure-regulation during oxygen-blowing has been attained thanks to the controllable variable-speed drives with which each mechanical pump is provided.

Aug 17, 2017

By Theodore James Kurela

Analysis of adverse technical issues has traditionally relied on a snapshot of the state of the operation complemented with both the melt shop’s archived data and eyewitness accounts of adverse events. The GrafTech ArchiTech System is helping EAF shops solve problems faster by combining continuous analysis of information with statistically based alerts of process deviations. After one year of system implementation, a number of cases have been detected and communicated to melt shops worldwide. The objective of this paper is to examine a few of these cases; the early detection, statistical analysis, deviation reporting and the resulting countermeasures implemented.

Aug 17, 2017

By Kyle T. Chomyn

Multi-disciplinary engineering analysis and advanced modeling techniques were used to identify and develop low cost design modifications to improve a blast furnace hot blast air distribution main that experienced frequent refractory failures. Piping flexibility analysis helped identify the root causes of refractory damage and determine the need for new expansion joints. Finite element analysis was used to optimize a custom-designed elbow-to-elbow tie-rod system, which ensures thermal expansion loads are not placed on connecting piping. Heat transfer coefficients through the elbows were estimated using computational fluid dynamics (CFD) flow modeling. The cast refractory design was changed to a more reliable brick refractory design. Excessive draft was occurring during furnace back-drafting, so the system was assessed using CFD, and a passive flow-reduction spool was designed. This firstprinciples engineering design approach allowed for optimization and verification, ensuring that the new design addressed the root cause of the previous deficiencies.

Aug 17, 2017

By Daniele Tolazzi

In today’s highly competitive market situation, it is of outmost importance for EAF steel makers to optimise their processes in order to reduce operating costs and to improve safety and reliability of the equipment. The laser based off-gas analysis technology, With laser units installed on the fix duct, downstream the combustion gap, uses the “Tuneable Diode Laser Absorption Spectroscopy” (TDLAS). The system performs real-time off-gas emissions measurements of CO, CO2, O2, H2O and temperature. A closed-loop operation is in place for dynamic control of the chemical energy package combustion/post-combustion of CO, H2 and CH4 gases into the EAF furnace shell. A statistical framework which builds on a data analysis engine, based on Danieli Automation Q3Intelligence technology, evaluates the “fingerprint” of the process represented by average and deviation trends of both gases and other process parameters. Process fingerprinting is conceived both for offline profile optimisation and on-line control of the refining process. This paper describes how the technology has been applied and the results achieved at ACCIAIERIE BERTOLI SAFAU (Italy) 100 t AC Electric Arc Furnace.

Aug 16, 2017

By Ivo Filipovic

The steel melting process in an Electric Arc Furnace is a complex set of tasks, coping with highly dangerous hazards as fire, explosions, uncontrolled reactions, hot metal projections and gas or dust emissions. Melt shops are dangerous working areas for operators, recording statistics with a high frequency of injuries. In the past years, without dedicated safety equipment, there wasn't a real attitude to the risk prevention. The paper describes the available technological packages to eliminate the manned activities on the melting floor, with the aim to prevent accidents and keep furnace operators safe. The technological packages suite extends the automatic control of the EAF melting process to all the operations from charging phase to tapping. Plus, the integration of the most frequent operations by automated specialized tools effectively minimizes power-off times, enhancing reliability and improving the transformation costs.

Aug 17, 2017

By Alberto Lainati

The Bar Reducing and Sizing Technology has a core function in the value-chain for the production of rolled SBQ (Special Bar Quality) products. The EVO 2+4-roll is based on the compact combination of a 2-roll high-reduction module followed by a 4- roll low-reduction module for precise sizing. The EVO 2+4-roll mill, allows to gain significant technical and economical advantages in the hot- and post-rolling process routes: dimensional and surface accuracy, quick adaptability to processing variances and to small lots requirements, superior technological features of as-rolled product, competitive capex and opex. The EVO 2+4 unit has a very compact design, which makes it suitable both for new mills and upgrade applications.

Aug 17, 2017

By Mühlböck Marlene

Increasingly stringent global environmental regulations are forcing steel producers to continually improve the efficiency of sinter waste gas treatment. With the Selective Waste Gas Recirculation (SWGR) system from Primetals Technologies, lower production costs can be achieved and the size of downstream waste gas cleaning units can be reduced for investment savings. SWGR features the extraction and reuse of hot sinter off gas from selected wind boxes along the sinter strand, which contributes to improved energy efficiency and off gas treatment in the sintering process. With the next generation of SWGR, Primetals Technologies can provide an energy optimized, emission optimized and environmentally friendly solution that meet customer requirements and country specific regulations. This paper demonstrates the latest developments in selective waste gas recirculation, especially results from pot grate tests and comparison from lab to real plant data. Furthermore theoretical finding and mathematical modelling is presented.

Aug 16, 2017

By Luke A. Balzan

Access to information is a key component for making improvements to any process. This is particularly true for all aspects of the iron mining and steelmaking process. The ability to make rapid control decisions can significantly influence process outcomes, including ensuring product specification, mining quality, transportation limits, upgrade factors, waste bypass and direct shipping, among many others. While traditional laboratory methods provide feedback for such processes, having access to analysis results in real-time can lead to positive reactive and predictive control decisions to be made rapidly, leading to significant improvements throughout the process. Scantech has been designing, manufacturing and supplying technological products to the minerals industry since 2002 to enable the availability of such realtime information to a mine or plant, with the benefits being enjoyed by a wide range of operators. This paper provides a summary of the available technologies used in the iron ore and steel industries, as well as providing a case study of their use at an Australian site, and a description of the potential benefits of a range of analysis equipment.

Aug 17, 2017

By Laurent Dorel

Surface quality monitoring is primarily implemented in the last steps of steel manufacturing before shipment to the end user. However, an increasing trend for also addressing this topic in the upstream stages, such as hot rolling plant, is tackled by Primetals Technologies to give steel producers the key to a global optimized yield management, and efficient “lessons learned” processes. After the last developments of SIAS Next Gen platform, including High Resolution and Near Infra-Red, some site results will be exposed on the very specific high constraints lines such as ESP Endless Strip Production and Plate Mills, and highlights the related most interesting aspects for our customers.

Aug 17, 2017

By Enif Gutiérrez Guerrero

Inclusion deposition is still a standing problem in the continuous casting of steel since the deposition of alumina inclusions inside the SEN affects the productivity and the product quality. The present work studies the factors involved in the inclusion deposition at the nozzle and the effects of inertial, gravitational, buoyant, pressure gradient, and Saffman forces on the inclusion trajectories. The results show that the inclusions reaching the nozzle, only 30% get deposited along its walls mainly at the Upper Tundish Nozzle (UTN). This area of higher deposition is identified close to a low static pressure and a high turbulent kinetic energy dissipation zones where the effects of the gravitational and buoyant forces do not promote a significant inclusion radial movement since these are aligned with the direction of the flow stream lines. In contrast, in this zone, the Saffman force shows an important effect on the deposited inclusions, slowing down the inclusions in the vertical axis and increasing their radial movement.

Aug 17, 2017

By Francisco Morganti

The market requirements which strip processing lines have to deal with have altered significantly within the last decades. Particularly, the production has to be economical and ecological efficient and processing lines have to cover a broad product portfolio. Already existing plants either directly or indirectly are competing with new plants, which are equipped with the latest technologies. The “Special Strip Processing Equipment” is designed to be integrated easily and within small downtime phases in existing lines. All single machines can be delivered in short time “ready-to-perform” with a tested and proved automation system. Thus, the competitiveness of existing lines can be increased immediately with less effort. To find out which machines can be reasonably implemented SMS group offers an “Efficiency Check”. A special proceeding is used by experts to find out quickly which machines will have the largest effect on the efficiency of the line while demanding at the same time the smallest expense.

Aug 17, 2017

By Andrea Taurino

Innovation means implementing a new product or a product that has undergone significant improvement over time, in terms of method, form and performance. Innovation encompasses all the scientific, technological, organizational, financial and commercial steps that need to be taken to put it into operation. Innovation combined with research and development makes it possible to perfect the product with consistency over time. Taking inspiration from the bases developed by the Austrian economist Joseph A. Schumpeter back in 1911, Danieli came up with the concept of “Innovaction” – a combination of Innovation and Action, to refer to the development and advancement of various products for the steelmaking industry, including the loop laying head for wire rod.

Aug 17, 2017

By Patrick Hansert

Safety was always in the focus of Badische Stahlwerke, however at the same time productivity has to increase as well in order to compete in a tough world market. In 2015 BSW produced over 2.2 Mio tons with two EAFs, leading to tap-to-tap times in average of under 40 minutes. Our philosophy has always been, that our most important success factor are the people: therefore we have to improve the working conditions as much as we can. Starting in 2012 Badische developed a robot that can support this goal. The first step was to use it for temp/sample taking, but the unit had to become a multi-tasker. Only 2 years later the first automated cartridge changer was installed at a customer site in Scandinavia, in late 2015 then the next tool was implement: tool changer allows now to use also a camera to check the condition inside of the heat after tapping. More tools are designed currently and will be implemented shortly. This paper describes the current installations and experiences as future applications.

Aug 17, 2017

By Gerd Weyand

Gontermann-Peipers GmbH (GP) Germany developed a new, high alloyed steel grade for the manufacturing of back-up rolls. The advanced GP double pour casting processes provide highest flexibility in being quite open in rolls work layer chemistry and hence microstructure with no influence on core respectively neck properties. GP took the process advantage to provide a brand new back-up roll grade with remarkably reduced roll wear while operating with textured work rolls. In the meantime several successful trials have been made with this new roll grade on different Skin Pass Mills. As a result the performance of back-up roll and thus availability of mill will be improved while specific costs for mill will drop. This quite new back-up roll grade has recently been launched. As next step increasing the field of applications is under progress.

Aug 17, 2017

By Carlos Gonzalez-Rivera

An alternative cooling curve analysis method focused on the experimental determination of the latent heat of phase changes and phase transformation kinetics is proposed in this work. The method analyses the cooling process of a metallic sample, initially liquid that is contained into a cylindrical metallic mold, both of known weight, thermally isolated at its top and bottom. The method is based on an energy balance associated with the experimental measurement of the temperature change of the sample and the mold during their cooling process. From the numerical processing of the cooling curves, are obtained approximate values of the acting global heat transfer coefficient as a function of temperature in order to describe quantitatively the energy exchange of the metal/mold system with its surroundings. These relationships and other experimental data are used to process the cooling curve of the sample and the mold during solidification, in order to obtain the latent heat of solidification.The method was applied experimentally to zinc and tin of commercial purity, initially liquids and contained into stainless steel molds in order to determine its ability to measure the latent heat of solidification. The obtained results suggests that this method shows a good potential to characterize the solidification of metals.

Oct 30, 2017

By Thomas Schanz

Current steel market conditions require small investments only to lower operational cost. SMS Concast has developed new products which optimize continuous casting process cost for long product steel production. This paper describes a selection of three products. All three systems are patented (patent pending for CONDRIVE). CONSAFE, a non-radioactive mould level measurement system for reliable mould level measuring on open stream casting CCM’s; CONSTIR-MWS, an improved control software for electromagnetic stirrers which lowers energy cost by 35%; CONDRIVE, a brand new oscillation drive system which provides the features of a hydraulic oscillator, however with a cost efficient electric drive.

Aug 17, 2017

By Alessandro Martinis

The performance requirements for modern steelmaking facilities are ever more stringent, as customers and markets are continuously pushing for technologies which allow having high quality steel produced in an economic and sustainable way. In the details, this paper has the aim to present the excellent results obtained by integrated steel plant where an EAF is fed with high quality hot ENERGIRON DRI. The recent technology developments, combined with the affirmed basic process design, contributed to further maximize the energy of the DRI, reaching the EAF at temperatures above 600°C with a carbon content up to 3.5%, as confirmed by plant data. These improved input material characteristics resulted in reduced electrical energy consumption and increased liquid steel production.

Aug 16, 2017

By Rudolf Hubmer

In October 2013 JSW Steel decided to place an order to Primetals Technologies Austria (former Siemens VAI Metals Technologies) for the installation of a comprehensive Level 2 process optimization system for more than 20 existing production facilities of various suppliers. For SMS-I new L2 systems are provided for two hot metal pretreatment stations, three hot metal desulphurization stations, three ladle furnaces, two 1-strand slab casters, a ladle tracking system as well as a shop supervisory system. Additionally the existing L2 system for one 1-strand slab caster is being upgraded in the course of the project. In SMS-II new L2 systems for the 7 hot metal desulphurization stations, 4 ladle furnaces, 1 new RH vacuum degasser, ladle tracking system and a shop supervisory system are supplied. Despite of the challenging time schedule the commissioning of the single facilities started within less than 12 month after contract effectiveness. The installed Level 2 process optimization systems together with the achieved results are described in this paper.

Aug 16, 2017

By Ananda Moreira Vaz Ourique de Avila

Ferritic stainless steels have been used in the making of high and intermediate temperature operation solid oxide fuel cells (SOFC) interconnects, replacing the ceramic materials. However, at high temperatures, on the order of 700-850 0C, these steels can present significant oxidation and degradation processes, promoting increased electrical resistivity and corrosion losses that result in contamination of the electrodes and reducing the performance and the useful life of the SOFC. Thus, the knowledge on kinetics of oxidation/corrosion of these steels and their relationship with the microstructural transformations are of great importance. In this study, samples of ferritic stainless steels AISI 430, AISI 441 and Crofer22APU® were tested for oxidation at high temperature (800 0C) for long periods of time (up to 3,600 hours) and mass gains were monitored allowing the determination of the oxidation behaviors of these steels. Additionally, the microstructural characteristics of the samples before aging (corrosion-oxidation test) and after various oxidation times were evaluated by optical (OM) and scanning electron microscopy (SEM), as well as by micro chemical elemental analysis (EDS) and X-ray diffraction (XRD) phase analysis. Electrical characterization allowed determination of electrical area-specific resistances (ASR) characteristics of the systems studied, thus relating the electrical and oxidative behaviors of steels evaluated.

Aug 7, 2018

By Ernst Lindemann

The SMS group has developed the ultrasound technology “HD scan” for inspection of the internal quality of as-cast products. This method of sample analysis requires less preparation work and is safer than the current, most common technique of etching and/or sulphur printing. Furthermore, this technology offers a three-dimensional view into the sample of the cast product and thus more representative information for a better quality evaluation. The internal quality evaluation can be performed automatically and objectively by software based on clear statistical methods. A quantitative centerline segregation rating can be assigned to each sample, based on the size and distribution of segregates detected by the unit. Internal crack statistic (length, position, orientation, etc.) and narrow side profile can also be measured. Grain macrostructure can also be visualized which allows for a potential optimization of casting parameters like strand cooling, soft reduction or electromagnetic stirring. The accuracy of the new method was proven by parallel metallographic investigations of more than 100 samples of different steel grades and sample shapes. Automatic defect evaluation and classification was compared against macroetching results. It was found that HD scan identified more defects and the visualization of the macro structure could be performed in more cases than with macro etching. All tests, comparisons, further developments and analyses for various steel producers and steel treatment companies have been conducted at the HD scan unit, located at the SMS group headquarters in Düsseldorf, Germany (Figure 1). Based on the results, SMS group has designed a unit which can be used in industrial scale.

Aug 17, 2017