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By Lidong Teng

ArcSaveTM is a new generation of electromagnetic stirrer (EMS) from ABB for electric arc furnace (EAF) operation. Its goal is to improve the safety, increase the productivity and reduce costs. Electromagnetic stirring in the melt bath during arc furnace operation will affect the scrap smelting, bath temperature distribution, refining reactions, and also the tapping practice. This paper has summarized the investigation results obtained from the first ArcSaveTM system installed in a 90 ton EBT arc furnace in USA. The hot test results show that ArcSaveTM has enhanced the heat and mass transfer in the arc furnace process. This results in a faster scrap melting rate, lower slag superheat during arcing, more homogenous melt bath, higher decarburization rate and higher EBT free opening frequency. ArcSaveTM has also reduced the tapping temperature and tapping oxygen in the steel. This brings a higher scrap yield and saves ferroalloy consumption in the downstream ladle furnace operation. The lower energy consumption, short tap-to-tap time, and consistent furnace operation bring increased productivity and safety.

Aug 16, 2017

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 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 Eduardo Vitral

The present study focuses in the simulation of pattern formation by ion beam sputtering on a material surface. This process is responsible for the appearance of unexpectedly organized patterns, such as ripples, nanodots and hexagonal arrays of nanoholes. A numerical analysis of preexisting patterns is proposed to investigate surface dynamics, based on a model derived from a Kuramoto-Sivashinsky anisotropic equation, in a two dimensional surface with periodic boundary conditions. While deterministic, its highly nonlinear character gives a rich range of results, making it possible to describe accurately different patterns. A finite-difference semi-implicit splitting scheme is employed on the discretization of the governing equation. Simulations were conducted with realistic coefficients related to physical parameters (anisotropies, beam orientation, diffusion). The study dealt with a random and a monomode 1D structure initial condition in order to understand how the shape and wavelength of the initial pattern evolve with time. Ripples and hexagonal patterns were observed in the results, being physically consistent with the phenomenon. Moreover, the Method of Manufactured Solution has been used as verification of the developed numerical scheme.

Aug 16, 2017

By Michael McDonald

The cold-rolled steel output of cold-rolling mill (CRM) complexes are sometimes constrained by their batch annealing facilities (BAF). This paper examines a cost-effective solution to increasing capacity and quality of the BAF thereby making additional capacity available for CRM output. The solution involves applying a structured system of scheduling and operation to the BAF, using a proven level-2 software model. The system presented has been applied to a wide variety of BAF with all the leading furnace brands. Whether using traditional HN atmosphere or 100% hydrogen, peak performance can be achieved when using a properly configured, on-line, physical thermodynamic model. Given that it is not practical to place a thermocouple in each coil that is being annealed, various methods have historically been used to estimate the time required to properly anneal all the coils in the charge. This paper examines how the latest technology, in wide use throughout the USA, uses a physical thermodynamic model to shorten average cycle times, thereby increasing productivity and reducing energy consumption. The paper also examines the benefit of building thermodynamically balanced charges to further optimize the BAF operation and improve quality consistency by decreasing mechanical property variations.

Jul 30, 2018

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 Yuechang Wang

A new method of manufacturing the wavy-tilt-dam(WTD) mechanical seal has been mentioned. In this method, the special equipment is designed to provide a predetermined force to external and inner circular surface of the ring. After milling the end face of the seal by grinding miller and releasing the preload, the wavy-tilt-dam can be done on the seal surface. In this paper, a prediction model is built up to investigate the relationship between the predetermined force and the deformation on the surface of the ring by using ANSYS software. A WTD ring is manufactured by this method which approves that the prediction model is in accord with the real process and this manufacturing method of the WTD mechanical seal is a proper choice.

Jul 31, 2018

By Gabriel Andrade Medeiros, Christian Brugger, Paul Pennerstorfer, Daniel Fuchshuber, Reinhold Leitnerl

State-of-the-art automation technology enables digitalization of the continuous casting process that goes far beyond conventional automation of industrial production. Primetals Technologies provides a digital twin that combines an intelligent digital representation of a casting machine as well as the casting process and the slabs, blooms or billets that are produced. It allows metallurgists and process engineers to predict the behavior of the involved complex production process and optimize parameters before using them in real production. New steel grades or production processes can be evaluated off-line without any risks to process stability and product quality. Primetals Technologies installs the digital twin with every new installation of a continuous caster optimization system. This paper describes how the setup and simulation possibilities of the digital twin provide numerous benefits by modelling and simulating the casting process. It allows for example the calculation of material properties according to the actual composition, strand surface temperature profiles and dynamic soft reduction before the final point of solidification. An outstanding feature of the digital twin is the replay functionality provided for various models to analyze and further optimize real production situations. The paper also gives an example how usage of the digital twin optimized production at a customer.

Oct 1, 2019

By Bruno Alves Resende, Antonio Adel dos Santos

Temperature, microstructure and dimensions are the main material parameters to be controlled during hot rolling of steel. Although thermal mathematical models have long been developed and applied for hot strip rolling, each Hot Strip Mill (HSM) must have its own model adapted to its facilities. Thus, a mathematical model for temperature evolution during rough rolling has been developed for the Usiminas HSM at Ipatinga Plant. The model achieved a high level of accuracy, which was assessed by comparing measured values of temperature at the hot strip mill entry with the calculated ones, the difference ranging from 9°C to 17°C. Application examples have shown that the slab can be occasionally stopped before start of rolling for as long as a couple of minutes without compromising its further processing. On the other hand, if the transfer bar stops after rough rolling even for short time, further processing in the HSM can be hindered, due to excessive temperature drop. In case of such abnormal line stop, the model can be used as a tool for decision-making to either continuing the planned rolling schedule or to changing the route, thus improving the overall rolling process.

Oct 1, 2019

By José Adilson de Castro

In the integrated steel industries the sintering process plays an important role furnishing raw material to the blast furnace. In this work, a computational simulation of the sinter process is developed that is able to predict the most important phenomena within the sintering bed. The model is based on the multi phase concept with multiple components described by conservation equations of each component coupled with the momentum, chemical reactions and heat transfer. The model validation was carried out comparing the model predictions with averaged industrial data and local temperature measurements within the sinter strand. The model predictions presented good agreement with the averaged values measured on the industrial sinter process.

Aug 2, 2018

By Francisco Morganti

Weight reduction is the main target of all carmakers, which results in a continuous development of new steel grades. Latest 3rdgeneration advanced high-strength steel grades (AHSS) are complex materials with special chemical compositions and multiphase microstructures. The pickling, annealing and galvanizing processes of these grades aresomewhatdifferent due to the changed chemical compositions and microstructures. Therefore, these innovative steel grades place new demands on the plant technology of pickling, annealing and galvanizing lines. The most significant challenges for the pickling process are sludge occurrence during pickling, varying pickling times, weld ability of the materials, changed visual appearance and required high surface qualities. The most important topic concerning annealing line is a precisely controlled and very flexible heating and cooling process in the furnace.One of the new requirements in galvanizing linesis the prevention of surface faults caused by bare spots, which can occur since these materials feature a higher content of alloying elements like silicon or manganese. Prevention is possible with the special pre-oxidation technologies.Due to the higher strength of the material also the mechanical equipment has to be designed differently in these lines. This paper describes the influences of the changed chemical composition and material characteristics of modern steel grades on the pickling, annealing and galvanizing process and gives an overview about the technical solutions.

Oct 30, 2017

By John Hinton

Electromagnetic based (EM) sensor technology has been shown to detect changes in the magnetic permeability of steel strip travelling down the run out table after rolling. Measuring below the Curie temperature, these changes can be interpreted in terms of the phase transformation from austenite (paramagnetic) to ferrite (ferromagnetic). These real time measurements provide a detailed insight into the changes in the structure at high temperature providing the steel producer with feedback on quality control, product consistency and product development. However unlike mill microstructure models, the sensor measurement provides a point reading at a distance through the cooling course. To map the transformation in more detail, a sensor array is required along the length of the Run Out Table i.e. to measure points on the austenite to ferrite transformation curve. This paper describes the process and metallurgical factors that should be considered in the optimum design of a sensor array, i.e. the number and location of the sensor heads. Examples of cooling strategies for different steel grades e.g. low carbon, structural and dual phase steels are used to demonstrate the importance of sensor location. In addition, the effect of variability within typical industrial parameters e.g. cooling speed, on the sensitivity of sensor output and location will be considered.

Oct 1, 2019

By Tobias Krull

The characterisation of iron ore from a materials handling point of view is paramount in order to provide the best possible design for the desired application and maximise equipment uptime at the lowest possible capital and operational expenditure. Problematic issues in materials handling applications often arise in the iron ore industry due to the high density of the ore as well as the abrasive nature of the product. One of the key issues encountered during the handling of iron ore is excessive wear due to either impact or sliding abrasion. The applications and equipment typically affected by accelerated wear issues are mass flow hoppers, transfer chutes and conveyor belts. These wear issues often result in unplanned down times and loss in production which can lead to a considerable loss in revenue. This paper provides an overview of the best practises in the materials handling characterisation of iron ore and discusses available techniques for the modelling of iron ore in applications where accelerated wear is experienced. The application is illustrated through a number of industry relevant case studies for which engineering design work was undertaken to successfully reduce the wear rates of different materials handling equipment.

Aug 1, 2018

By Chad Byron Donovan

There is a strong need in North America and other major steel producing markets where major capital investment in new equipment has been minimal over the past several years to make improvements to existing casting machines. In many cases, very cost effective improvements can be made to existing equipment in order to maximize the efficiency and production of an older designed continuous caster, a classic caster. SMS Group and its predecessor companies have been maintaining continuous casting molds for over forty years. This experience has allowed SMS Group to intimately understand the advantages and disadvantages of each design. The most vital component of the continuous caster is the mold copper design, as it has the most influence over the ability to cast a quality product. Updating to a modern copper design is less complicated than most steel producers think and the benefits are significant. Premium mold coatings such as UniGuard® and NanoGuard® allow casters to guard against exposed copper and wear while producing quality products for record campaign lengths.

Aug 16, 2017