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By Norbert Asamer, Stefan Purrer

Depending on the product or the material grade, conventional deburring machines, such as e.g. with rotating hammers, are in many cases not capable to reliably or completely remove burrs from the edges of a continuously cast product. Burr, however, is generated at the front and/or tail ends of a slab, bloom or billet as a result from torch cutting. Likewise, traversal grinding of the slab’s rolling surfaces can also cause burr at the long side edges of the slab whereby such burr can even be more difficult to remove. Based on their experience and know-how with abrasive machining processes (abrasive cutting, high-pressure grinding) over a period of more than 50 years up to now, BRAUN has developed a highly flexible deburring grinding machine for applications which are too difficult for conventional deburring techniques. BRAUN’s deburring grinding machines were successfully introduced to the steel industry and have proven their worth under normal production conditions already. The subject paper describes the key features and advantages of BRAUN’s machine design and the operational results from the first already completed projects.

Oct 1, 2019

By Silvio Cecchini

State-of-the Art Mould Level Control Solutions for continuous casting applications face different challenges. On the one hand, technological phenomena such as clogging and unclogging, unsteady bulging or waving can create unpredicted meniscus disturbances by completely changing the casting channel geometry and the flow behaviour of liquid steel to the mould. On the other hand, from the viewpoint of caster operations, long lifetime, quick interchange-ability and integration capability into existing systems must be achieved. In the present contribution, the overall development of INTECO TBR’s mould level master – a comprehensive mould level control solution for all continuous casting applications – will be introduced. The basis for the presented system is a development over several years which includes investigations of all critical components such as shroud, stopper, stopper mechanism, servo actuator and mould level control program. These investigations finally resulted in a new-ly developed control algorithm for a highly dynamic servo actuator. The control algorithm with its basic functionality such as the prevention, identification and removal of clogging impacts with the associated automation functions to reduce their influence onto the overall mould level control performance will be presented. The scientific basis, the resulting control functions and their related automation implementation will also be illustrated. Finally, a patented control algorithm and control functionality for unsteady bulging and waving effects with the associated automation functions to reduce their influence onto the overall mould level control performance.

Aug 16, 2017

By G. Martino, F. Silva, Emmanuel Marchal

The definition of the chemical specification at multiple steps of the steelmaking process is very common in the industry. Among all elements and compounds, the Sulphur content has a special control over several stages, from the coal blend to the final products. Coke, iron and steelmaking specialists usually agree on a static specification for each intermediate product according to their local operation capacity and production cost. However, local decisions have major impacts on the whole production chain and many global factors should be considered in order to make the best decision. In this study, we will exemplify focusing on Sulphur content concepts and techniques that could be applied to many decisions in an integrated carbon steel plant. The variation of coal and coke prices, the desulphurization cost and time, the processes operating points, the hot metal rate at converters, prices and demands of low and ultra-low Sulphur steel grades are some of the integrated factors that are usually disregarded during the specification process. Mathematical modeling presents itself as a proper option into dealing with all the complexity that emerges from integrating all these processes' trade-offs and decisions. This study presents the results of a mathematical model that encompasses economic, thermal, chemical, and mass balances, physical quality of materials and productivity constraints of all processes of a hypothetical integrated carbon steel plant. It optimizes the iron and steelmaking process on a global and unique objective, dynamically defining targets for product quality to achieve the lowest steel production cost. This study details multiple market-plant scenarios in order to compare economic and operating results of a static vs dynamic specification practice.

Oct 1, 2019

By Jürgen Schanderl

Cold rolling mills by SMS Siemag are well known for their reliability and long-life cycle. They are an investment in the future. Nowadays mill owners are under considerable competitive pressure and are asked to organize production in a more and more efficient and flexible way. Doing so, a number of elevating screws have to be turned. These are: cutting of operation costs, especially by more efficient equipment and processes as well as transition to more process flexibility to fulfil future product requirements. To support owners in their effort, SMS Siemag offers convincing solutions in cold rolling technology under the brand X-Roll 2.0. Examples to be presented are: Sieflex®-HT drive technology; Redesigned DS system; New reel design: Twin Reel; Emulsion compact unit ECU Compact; TRC® threading assistance system; ECOMode and Energy ADVISOR monitoring system.

Jul 30, 2018

By Jean-François Stumper, Mario Moser, Mark Kruessmann, Volker Langer, Daniel Bastos Martins Cruz, Claude Meisch

The latest generation of probes and casthouse machines provide a wealth of data that has not been available a few years ago. The evaluation of this data gives direct feedback to improve the blast furnace efficiency, the equipment maintenance and design and it allows the early detection of critical or deviating process situations. A stable operation with lower operation and maintenance costs are the final customer benefits.

Oct 1, 2019

By Francois Mignard

With a limited global steel production growth, automotive application market shows interesting volumes and trends especially in emerging countries. The recent period has again enabled Siemens VAI to confirm a position amongst leading suppliers of new plants serving high-end steel production in particular for unexposed and exposed automotive material. With a series of recent plant references in operation and under construction, relevant answers to such sustained level of performances are highlighted along the downstream processes. Designed for a wide range of applications, Siemens VAI processing lines includes advanced technological and state-of–the art equipment, among them, Solid state laser welder, Pickling Tunnel tanks, Skin pass mill and Tension leveller, Side trimmer with dynamic width adjustment, and new generation of Automatic surface inspection systems. With a continuous aim of driving improvements, Siemens VAI has also developed Global Quality Monitoring solutions notably through advanced software which provide just-in-time warnings and assist steel makers in the daily operation of their lines. As lifecycle partner, Siemens VAI offers solutions and services in metallurgical expertise from metallurgical modelling, through physical simulation on rolling, annealing and galvanizing processes, and enables Siemens to accompany our customers along with their project definition till fulfilment of highest market requirements.

Jul 30, 2018

By Aperam South America

Balanço Energético Global e Utilidades - 2013

Jul 31, 2018

By Detlef Ehlert

Flexibility in terms of producing high sophisticated products with an exceptional wide range of properties and dimensions requires physical based process models for the generation of optimal set points. Therefore SMS applies since many years an integrated PSC® (pass schedule model), PCFC® (profile, contour and flatness model) and CSC (cooling section control) for the use in hot strip mills, CSP® plants and plate mills offering best possible product tolerances. Focus during the development of the model was made on the best possible physical description of the rolling process to minimize the need of complex adaptation algorithms. As an addition SMS has also developed a microstructure model to ensure the quality control with respect to mechanical properties and to save up the needs of taking samples. Beside of this the modular design of the Microstructure and Material Property Model (MPM) offers additional benefits to improve the accuracy of the other models, e. g. the recrystallization model in the finishing mill. Using the results of that model strain hardening or softening effects during rolling can be predicted and an optimum pass schedule can be calculated to avoid rolling stability problems related to phase transformation.

Aug 16, 2017

By Enrique Francisco Somolinos Garcia-Morales

In this paper we will discuss the benefits of a very innovative way of introducing MgO in the blast furnace operation through the sinter, using mini lumps of dunite. By changing the traditional way of using an MgO bearing material in fines form (particle smaller than 5 mm), most of the MgO inserted material behaves as inert during the sintering process, with the effect of having the following parameters (among others) improved: productivity at the sintering bed, permeability inside the blast furnace, energy consumption, stability of the operation.

Aug 1, 2018

By Bimal Nathwani

This paper presents an overview of bearings failures with focus on steel mill applications such as continuous casting, rolling mills, multi-roll cluster mills and wire and rod mills. This paper will also provide countermeasures for prevention of these modes of failures.

Jul 30, 2018

By Alain Denis, Marcelo Curtes Martins, Jeferson Rocio de Oliveira

In this work we present a study of optimization of a new inhibitor for turbulence pickling line. The efficiency of inhibition was measured and the weight of loss was evaluated in four different materials to optimize the dosage of the inhibitor. In seven months we had 8.7% of reduction in pickling losses.

Oct 1, 2019

By Jefferson Lisboa Lelis, Marcos Roberto Soares da Silva, Maiara Rodrigues Gouveia

Nowadays, due the development of new hot rolled strips at USIMINAS, established the necessity of realizing studies to define new parameters for the welding machine of new pickling line, in order to improve mechanical and metallurgical properties of these materials. The aim of this study was to evaluate the weldability of high strength low-alloy steel with low boron content with tensile strength above 600MPa.The influence of energy input and preheating temperature on the mechanical properties of hot rolled strips were analyzed at three distinct thickness (2, 4 and 6 mm). To perform these evaluations were used tensile test, micro-hardness, metallography (micro and macro examination) and scanning electron microscopy analysis. In resume, a good welding performance was achieved, increasing preheating temperature and the welding energy higher than 60%.

Oct 13, 2019

By Juliano Braz Possatti, Arnaldo Carneiro Salles, Cleudson dos Santos Rego, Leandro de Lucas Mendes

The increase in customer demand for steels with higher surface requirements, associated with the need to increase ArcelorMittal Tubarão's HSM productivity, it was necessary the development of controls and actions to reduce scale losses within the scenario of high productivity. This article describes the path followed by the hot strip mill team in order to reduce the occurrence and severity of scales.

Oct 10, 2019

By José Fagundes Junior, Cleudson dos Santos Rego, Bruno Bastos da Silva Murad, Vitor Borlot Borba

Since the startup in 2002, the Hot Strip Mill at ArcelorMittal Tubarão has increased gradually the coil output as the customers demand new and more resistant dimensionally challenging (thinner and/or wider) steel grades. As a critical feature for customer applications, improvements have been carried out aiming a higher thickness performance and reduction of internal losses while still meeting the more restrict tolerances booked by the customers. This paper presents the recent thickness performance evolution since 2017 and the main actions deployed to improve it.

Oct 1, 2019

By Piezanowski Ludivine

With the aim to reduce the hot metal production cost, ArcelorMittal Gent decided to integrate more ores with finer particle size distribution in the raw material mix for the production of blast furnace sinter. As a consequence of such an increase of finer material in the sinter raw mix, the sinter machine productivity and the quality of the sinter are affected. In order to compensate this impact, modern granulation technology can be employed. Within this context, ArcelorMittal Gent has invested in a vertical intensive mixer. The equipment was placed before the existing drums, with a function of “mixer”, whereas the drums are fully optimised for the nodulizing process. The paper presents the results of the industrial operation during the commissioning phase of the new equipment. Gradually increasing the proportion of fine material in the sinter raw mix has made it possible to compare the performances of the old system using drums for mixing and pelletizing with the new system using an intensive mixer combined with a nodulizing.

Aug 1, 2018

By Valeria Romina Stricker

Acerbrag es una empresa Argentina siderúrgica de 50 años de trayectoria, desde el año 2007 pertenece al grupo Votorantim de origen Brasilero. Se dedica a la elaboración de aceros largos para la construcción. La planta industrial cuenta con un proceso de acería integrado, horno eléctrico, horno cuchara y máquina de colada continua. La materia prima es 100% chatarra, característica que la diferencia del resto de las acerías del país. Debido a esto el enfoque principal de este proyecto es reducir el costo de fabricación mediante un “empobrecimiento” de la carga metálica a partir de la flexibilización de los límites de especificación. Esto implica un mayor control del desempeño de los procesos a fin de detectar posibles desvíos, para ello fue necesario implementar la utilización de herramientas estadísticas y gráficas para su monitoreo. La modificación en el mix de fabricación no muestra una alteración significativa en la composición química y propiedades mecánicas de los productos terminados, situación favorable para la continuidad del proyecto. Se observa además, de la reducción de costo esperada, una ventaja en la operación del patio de chatarra y el proceso de acería y en la utilización de chatarras con altos niveles de residuales tales como Cr – Ni.

Aug 16, 2017

By Gabriel R. Royo

This paper will cover a back up roll bearing technological upgrade, being implemented at the TERNIUM SIDERAR Hot Strip Mill (HSM), in San Nicolas, Buenos Aires, Argentina. This change was motivated by increased operating loads, which caused the original bearings to be outside the designed bearing rating. The problems were first identified by bearing seizures in some stands, and later followed by cracks forming in the back up roll neck areas due to fatigue and overload. MORGOIL engineers worked together with TERNIUM SIDERAR engineers in analysing the problem and to upgrade the mill with the newest and most economical technology. The upgrade consisted of changing the bearings to the latest generation MORGOIL bearing: the KLX, which within the same space, increases bearing capacity around 25%. This was accomplished re-utilizing all chocks. The new bearing allowed for a re-design of the geometry of the back up roll neck, making it much stiffer than the original design, and eliminating fatigue failures. In addition, an upgrade to hydraulic mounting and dismounting using the MORGOIL® HB lock was also implemented, as well as changing to the newest MORGOIL® HD seals. With the MORGOIL® KLX® upgrade, TERNIUM SIDERAR HSM increased load capacity, allowing them to roll products that were not even considered decades ago. Both older oil film bearings and roller bearing mills have been successfully upgraded while reusing existing chocks and in many cases rolls. Solutions are customized to the customer’s equipment and goals.

Oct 30, 2017

By Vitor Guarnier Domiciano

Pre-shaped refractory burner blocks play an important role in reheating furnaces operation and melt shops production since they are responsible for heating the billets/plates so that they reach the temperature required for lamination. This paper presents the main characteristics and properties of a new refractory castable developed for pre-shaped burner blocks, which significantly improved the performance of reheating furnaces burner blocks. Tests carried out in 3 different melt shops have shown that the new refractory castable was able to extend the service life of the refractory burner blocks from 1 year (standard product) to more than 3 years (new castable), showing perfect conditions to continue operating for a longer period.

Oct 30, 2017

By Shanti Arangala

Several improvements were made to the single strand rod mill at Laverton to increase production, reduce maintenance and improve several aspects of product quality. With changes to the water cooling line and control system, cobbles could be significantly reduced, more consistent properties obtained and yield improved. An upgrade of the laying head enabled vibrations to be reduced and thus allowed for higher speeds on small sizes. With potential for dramatically increased pipe life, a new pipe support and laying pipe system provided for improved laying pattern on small sizes and thus more uniform cooling on the conveyor and better coil package. This paper discusses details of these equipment and control system upgrades and the resulting benefits that have been realized from the project.

Aug 16, 2017

By Vitor Guarnier Domiciano

The need to adjust the monolithic refractories to increasingly severe and unstable Blast Furnace casthouse operating conditions has been a major challenge for refractory suppliers in order to guarantee the runner’s safety and its availability for operation. This paper presents the properties of a new robust single line Al2O3-SiC-C refractory castable developed to endure the severe operating conditions that main runners are facing in today's Blast Furnace casthouse scenario. Practical results during almost one year of testing revealed a significant lower wear speed of the new refractory lining when compared to a standard product.

Aug 1, 2018