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By Konrad Krimpelstätter

The need for more effective and flexible roll-gap lubrication technologies in hot and cold rolling mills is steadily increasing due to ever-greater requirements placed on the rolling process and the final products. In particular, the rolling of high-strength steels poses enormous demands for both the rolling mill and the coolant/lubricant to be used. The presented paper focuses on two innovative technologies for highly efficient roll-gap lubrication for hot and cold rolling, which were developed utilizing extensive knowledge and expertise about the tribological interactions in the roll-gap. The advanced work-roll lubrication package (A-WRL) for hot rolling and ESP mills is using specially designed mixer-nozzle units to mix the water/oil emulsion very close to the nozzles to minimize the risk for contamination and clogging. The nozzles are quickly exchangeable and are optimized to ensure uniform lubricant distribution, high plateout efficiency and minimum oil consumption. This eco-friendly solution does not require any chemical additives or cleaning agents and significantly reduces electrical energy consumption and work-roll wear. The roll cooling system on mill entry and exit side remains switched-on, which is of vital importance especially for highperformance hot strip mills. Minimum Quantity Lubrication MQL® represents a new generation of roll-gap lubrication technologies for cold rolling, which applies minimum amounts of pure rolling oil finely atomized with pressurized air directly onto the work roll surface. This allows controlling the oil film thickness depending on actual process and product parameters, providing increased lubrication flexibility, significant improvement of strip surface cleanliness through reduction of strip wear. MQL® was successfully installed and tested on two industrial tandem cold rolling mills in Europe. Advanced WRL and MQL® represent Primetals’ latest technologies that feature a robust and reliable system comprising standardized interfaces and flexible communication options. Both packages can easily be integrated into existing or new hot strip mills, ESP lines or cold mills.

Aug 17, 2017

By Stanislas Mauuary

Price pressure is a real challenge on the stainless steel market. With market globalization, increase production capacity and exorbitant raw material, the margins are squeezing for stainless strip producers. Primetals Technologies offers a wide range of advanced technological solutions to secure the margins of our customers. Our solutions, implemented with professional project management, allow an optimum coil to market time, securing then the return on investment for the investor. Among the possible lever used to optimize the production route, one drastic step can be made to cut rolling time and cost by replacing the common 20-Hi mill stand reversing process by state of art high capacity X-HI® stands in continuous rolling line. Other source of savings can be implemented by integrated several process steps together (rolling, annealing, pickling, skin passing), achieving then savings on stocks and logistics while coil processing is reduced to fraction of hour. Additional solutions can also be implemented on the new, as well as existing line, like maintenance free solid state laser welder, skin-pass and tension levelers, in-line inspection system coupled with process and quality management system.

Aug 17, 2017

By Karl Berger

As the hot rolling of steel moves into new more compact and effective processes, and as steel producers look for new ways to reduce their costs and increase their margins in ever tightening markets and tolerances, the evolution in Steckel mill technology, layouts, and new innovations may well keep the Steckel mill as a viable option, especially in areas of the world where minimized capital investments are required. In this paper we examine the evolution of the Steckel mills over the last two decades, with emphasis on new innovations and practical results, and provide a summary of hands on experience with some of these innovations. Also a focus on the South American Installations is given (from Siderperu to Gerdau’s newest Combination- Plate-Steckel-Mill). In addition, we aim to show the viability of the Steckel mill as an option for many existing or prospective steel producers, as the quality of the products rolled with Steckel mills reaches new quality parameters and as new innovations permit the rolling of thinner and wider materials, reaching new applications and wider share in markets, while maintaining a strong foothold in the traditional uses of Steckel mill products such as stainless steel, structural, and line pipe materials. As the ability to handle heavier, thicker, and wider coiled plate products increases, the coiled plate Steckel mills option is as strong an option as ever.

Aug 17, 2017

By Nestor Cezar Heck

Aim of the present work is to continue the theoretical evaluation of the slags of the fundamental system CaO-SiO2-CrOx-MgO (Ca-O-Cr-Si-Mg quinary system) at the temperature of 1,873 [K], with the help of a computational thermodynamic tool. Driving force for this and the previous research works is the understanding of chromium losses from the molten bath into the slag. Especially motivating is the presence of solid phases in the slag, since they may prevent refractory degradation and help in the production of foaming slags. Nevertheless, Cr-bearing solid phases can lead to Cr losses, being therefore detrimental. Determination of the states of thermodynamic equilibrium for this system using a slag with fixed composition as a start material were made using MgO amount as variable. Results show the impact of the MgO content on the equilibrium phases (molten metal, liquid slag, solids) and their composition for this system.

Jul 30, 2018

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 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 Christoph Aichinger

The optimization and improvement of a modern integral iron and steel works gets more and more difficult as each individual plant is already operated at its best efficiency and at the lowest operational expenditures. However very often the individual plants are considered as stand-alone units and there are losses and inconsistencies on interfaces and take over points, which could be avoided and by that improving the overall performance of the iron and steel works as a holistic unit. Primetals Technologies looked into this subject extensively in the recent years and is now ready to offer new tools and services in order to assist operators to find further potential for improvement in processes, which seem to be fully developed at first sight.

Aug 17, 2017

By Márcia Maria da Silva Monteiro Pereira

Tundish is the last reactor where significant metallurgical operations can still be done. Calcium aluminate slags are able to positively contribute to metallurgy considering oxide separation, protection against reoxidation and preclusion of resulphurisation. However, these are poor insulators. When using low melting point slags it is necessary to use another covering material. The deviation from saturation can be used as a measure of absorption capacity. By utilizing computerized construction of ternary and quaternary diagrams it is possible to compare different slags and to find proper slag compositions with reasonable capacity to dissolve inclusions. Objective of the present technical contribution is to evaluate tundish slag capacity to absorb inclusions, considering a particular tundish industrial slag and the changes in its chemical composition during continuous casting of steel. It was observed that slag composition changed during the continuous casting process; this variation is possibly related to interaction between the CaO-Al2O3 liquid slag and the rice hull ash layer which is used above it. Computational thermodynamics was used to determine activity of alumina dissolved in liquid slag; it was observed that the variation in slag composition did not change slag capacity to absorb inclusions, since precipitation of Al2O3 solid phases is not predicted.

Aug 17, 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 Companhia Siderúrgica Nacional - CSN

Balanço Energético Global 2013

Jul 31, 2018

By Gerhard Finstermann, Ichiro Maeno, Takehiko Saito, Hironori Shimogama, Konrad Krimpelstätter

Automobile manufacturers are developing Electrified Vehicles with light steel body structure designs that reduce mass and therefore greenhouse gas emissions over the vehicle’s entire life cycle. This raises the demand for the production and development of Advanced and Ultra High-Strength Steels (AHSS / UHSS) and Electrical Steels with increased permeability and reduced core loss to improve energy conversion efficiency. To meet this requirements the steel market is tending towards new generations of AHSS with improved formability (3rd generation AHSS) and high-silicon steels with higher strength and thinner products. With this growing demand for advanced high-strength steels and electrical steels, producers are faced with a unique and interesting challenge in producing materials that strain or exceed the capabilities of existing mill equipment and automation designed to produce low- to medium-carbon sheet. While specialty steel producers have known for decades how to process special high-strength steels and thinner gauges, this equipment typically does not offer the yield and productivity desired by the market, necessitating innovation in re-engineering existing equipment to meet the market demands more economically than new construction. In the case of cold rolling, this can be supported through variable roll geometries, more effective roll-gap lubrication technologies, application of strip heaters (Warm Rolling) to reduce risk for edge crack propagation and strip breaks as well as continuous rolling managed by state-of-the-art automation technologies.

Oct 1, 2019

By Qingwen Dai

The Marangoni effect is an important phenomenon where a surface tension gradient drives liquid towards high surface tension regions. Temperature gradient, evaporation, disparity of viscosity, and surface roughness and topography are all significant factors that can affect this thermo-capillary migration. The purpose of this study was to investigate the influence of micro-groove patterns on the migration of paraffin oil, and obtain a well-designed texture of micro-grooves to prevent the thermo-capillary migration. Patterns of micro-grooves with differing orientations and geometric parameters were fabricated on the surface of SUS 316 stainless steel substrates. Experiments on the migration behavior with different viscosities of paraffin oils were carried out various temperature gradients. The experimental phenomena indicated that the surface with the micro-grooves perpendicular or parallel to the temperature gradient have a strong impact on the migration performance of paraffin oil. Micro-grooves perpendicular to the temperature gradient exhibited extraordinary slower migration velocity than that of the parallel one. Width and depth of micro-grooves had an obvious influence on the behavior of temperature-driven migration and detail discussions on the effects of these geometric parameters were carried out.

Jul 31, 2018

By Rudolf Lesch

Till date, coke has been produced mainly from coals with a content of volatile matters in the range of 20% to 28% and good coking properties. If such so-called "selfcoking" coals are available, blast furnace coke or foundry coke with the required quality characteristics can be produced in top-charged horizontal ovens. In this case, the possibility of using high-volatile coals and in particular coals with low-caking properties is very restricted. Even if high-volatile coking coals have good coking properties, coke produced from such coal alone will not meet the requirements in terms of coke strength. The mechanical coke properties are influenced by the charge coal blend and the coking conditions. In this context, the bulk density of the oven charge is a decisive factor. Research and development in the field of coke production in horizontal chamber ovens aims at improving the specific oven throughput, increasing the raw material basis and introducing environmental protection technologies. The key factor, however, is to guarantee and further improve the rentability of the coke production. It is very important to reduce the cost of the charge coal to a minimum at the same time maintaining or even improving the coke quality.

Aug 17, 2017

By Alessandra Spaghetti

Rolling small-diameter hot wire rods at high speeds with conventional laying head pipes can wear the pipe out frequently and affect quality and consistency in the final product. Laying head upgrades using Sandvik SAF2507LHP™ (UNS S32750) tubes make possible to achieve optimal metallurgical properties, smooth coil formation and easier coil handling. Operators can also avoid unwelcome shutdowns due to frequent worn pipe changes and turndowns. Sandvik have been developing different customers and understand their process needs. The suitable selection materials that are able to withstand high levels of wear better than low alloy and carbon steel grades that are commonly used in industry is very important to improve the quality and increase productivity. UNS S32750 tubes were demonstrably superior to low alloy and carbon steels when used in Laying Head Pipe system regarding tubes lifetime, reducing replacement, production interruptions and increasing reliability.

Aug 17, 2017

By Werner Klein

The utilization of production facilities in an optimum way, with reliable due date fulfillment, reducing raw material and energy consumption, are challenges iron and steel companies are facing in their business every day. By using an APS system such goals can be achieved to increase the competiveness of iron and steel producers. A sophisticated APS supports the overall planning process by applying complex rules based on product and order mix, its production routings with corresponding processing and transport times and resource availability. Specific technological as well as steel grade and energy related constraints are also considered to meet company specific KPIs. A core feature of APS solution is to react online on deviations to plan during the production process. Deviations such as nonconformance of intermediate material attached to an order, sudden production delays, unavailability of important production resources, makes it necessary to update the production plan. In general the task of APS is to support the preferred work-to-order concept, by assigning work-orders to available production facilities along the product specific process route and generate optimized material sequences for critical work centers.

Aug 17, 2017

By Alberto Pesamosca

The present work analyzes the latest results achieved in scrap based EAFs in terms of application of chemical energy, starting from the observation that the general trend is a reduction of oxygen utilization. Consequently a review is needed about criteria for evaluation of melting process efficiency and equipment design. If from one side the maximization of productivity remains one of the major goals, from the other side some aspects of present market situation, included price of raw materials, are requiring the maximization of process yield. Based on achieved performance figures of selected plants and theoretical considerations, the effect of chemical energy input intensity is analyzed focusing on transformation cost, productivity and total energy input. The effect of present practices with lower oxygen utilization is considered also in terms of global CO2 emissions. Finally, the latest Danieli concepts and technological tools for optimization of chemical input are presented.

Aug 17, 2017

By Leandro Rigo Ramos, Marcelo Lucas Pereira Machado, Lumena Gloria de Souza Nunes, Mariana Valinhos Barcelos

The aim of this work was to study the influence of temperature on the grain refining process from severe plastic deformations through the simulation of Accumulative Roll Bonding (ARB) by torsion tests. The assays were performed to simulate the ARB at three different temperatures of 550 ° C, 625 ° C and 700 ° C with 5 torsion cycles with equivalent strain of 0.8 per cycle at a rate of 0.1−1 , totalizing an accumulated deformation of 4.0. Grain refining was obtained with an average size of 2μm, 5μm and 6μm for the temperatures of 550 ° C, 625 ° C and 700 ° C respectively. There was a rise in Vickers hardness by 68%, from 119HV in the annealed sample to 175HV in the deformed sample at 550 ° C. In the deformations at 625 ° C and 700 ° C the value of 130HV E and 150HV respectively was obtained. Based on the obtained results, it can be stated that the severe plastic deformations in microliged steel, carried out at temperatures lower than the end of the austenite-ferrite transformation, produce refined grains of the order of 2μm and, consequently, increase the mechanical strength of the material.

Oct 1, 2019

By Gigliola Salerno

The carbon-epoxy composite has high specific resistance and strength, which means specific applications. However, its behavior under compressive stress could be decreased by delamination, needing more detailed studies. The main purpose of the present work is to verify the mechanical properties in bending process considering two different fiber orientations. The composite materials were made by woven fibers and epoxy resin. Primarily, the carbon fiber fabrics suffered a superficial physical treatment called silanization, in order to developing a better chemical adhesion between fibers and resin. After the superficial treatment, the layers were embedded with epoxy resin. The composite resin’s cure was made in a Fanem heater, model 320, during 1 hour at 120°C at 1.5 bar; subsequently the specimens were cut by water jet. Specimens oriented in 0°/90° and 0°/90°/45 were manufactured and taken to bending tests, accordingly to the ASTM E855 and D790 standards, in an universal testing machine MTS – Material Test System, full capacity of 250 kN. It was concluded that all specimens failed by tension. Specimens with internal void volumes results in lower flexural modulus and those with presence of fracture mechanisms, like delamination, showed lower strength values. Scanning Electronic Microscopy demonstrated the damages involved during bending process.

Oct 30, 2017

By Antonio Esposito

Saving energy and reducing resource’s consumption by minimizing emissions are today great challenges in the coking industry worldwide. In order to achieve satisfying results, equipment as well as technology should be continuously improved and designed to minimize the energy requirements and to maximize the recovery of materials and energy. The sensible heat in coke pushed out of oven chamber takes up 35 ÷ 40 % of energy consumption of coke oven. Usually the coke thermal energy is lost during traditional coke wet quenching, necessary to reduce the coke temperature for the storage and the following use in steelmaking processes. BPSL CDQ project is a sample how Paul Wurth’s technology allows to reach the energy saving goal and offers an alternative to traditional quenching. With the adoption of Coke Dry Quenching process, a considerable amount of this sensible heat in the coke can be recovered by producing steam; its production depends on various parameters, some of them battery related (Volatile Matters in red hot coke) and others CDQ system related (coke burning losses, superheated steam characteristics (i.e. P,T)), greatly depending also on boiler efficiency (heat exchange efficiency, insulation of the boiler itself, air leakage, etc.). The adoption of CDQ process reduces also the water consumptions in comparison with traditional quenching.

Aug 16, 2017

By Andrea Zanon

Recently steel manufacturers have significantly focused their attention on safety and working conditions thanks to new labour laws, comprehensive operators’ knowledge and increased company social responsibility. Even with a reduced budget, investments on safety are now widely approved. Mill constructors aim at developing upgraded solutions to comply with these new requirements. In some cases mill constructors can even anticipate customers’ requests and consequently put into the market innovative solutions. In this text we will analyze some advanced solutions developed by Danieli & C. Officine Meccaniche Spa - the leading company in long-product rolling mills - aimed at improving working conditions on wire-rod block settings. In particular, we will focus on rolling guides installed on fast-finishing blocks and on servo-assisted device for rolling rings changing. In fact, this equipment has shown effective benefits on our test plants and has mainly cut out the tendency of the personnel to be absent due to backache. This paper will first present standard working conditions, will then introduce the newest equipment developed by Danieli & C. Officine Meccaniche Spa, will analyze its operation and finally will describe in detail the benefits that can be reached with its use.

Jul 30, 2018