Simulation experiments were conducted to identify the dominant factors that affect topdross generation in metal coating baths. From the experiments and the microstructuralanalyses of the top dross, it is proposed that top dross is generated through bath metalentrainment by the oxide film and subsequent drainage during holding. A new concept,taking into consideration the fresh area creation during the wiping process, is introducedand a mathematical model is developed to quantify dross generation in the metal coatingprocess. From the proposed mechanism, a new metric is developed to quantify top drossgeneration in the coating bath. The experimental results agree well with both theoreticalresults and production data of galvanising (GI) baths based on this metric.

In order to extend the RH lower vessel campaign life and to recycle used retractories, MgO-C bricks were applied for the RH lower vessel. As a result, the campaign life of the lower vessel has been extended by approximately 15 % , compared with magnesia- chromite bricks normally used. It was further ensured that it was possible to refine ultra-low carbon steel under these conditions.

Hot tearing defects appear during the last steps of casting solidification of dendrites.The crystalline structure traps a small amount of liquid metal, which is depressed, andcavities are spontaneously initiated. Molecular dynamics (MD) simulations of pure iron areable to predict, on one hand, the high temperature elastic modulus of crystals, and on theother hand, the cavitation event in liquid metal and near the solid-liquid growth front.High values of elastic tensor components are predicted close to the melting temperature.We conclude that a weakening of the mechanical properties of the crystal is not the reasonfor failure initiation. The crystals are thinned by partial melting as the effect ofnegative pressure increases. The cavitation is spontaneously initiated under a very highnegative pressure. The cavity expands very quickly and applies a pressure wave to thethinned crystals. We propose that this crystal thinning/pressure wave coupling is able toinitiate cracks inside the crystal.

The paper presents the work done to assess the usefulness of the thermographic analysis in the design of a detection system for longitudinal defects in coils manufactured by a tandem cold mill. The approach started with a first phase devoted to the development of a computer system for the acquisition of high resolution thermal maps of the whole strip. In the second phase the thermal maps are classified and related to the process variables.

Classically, the simulation of primary recrystallization and grain growth starts from a theoretical microstructure defined numerically and characterized by a random texture distribution. The results obtained in this way represent well the overall behaviour of the material during annealing, but do not allow to obtain a local description, consistent with reality. In such procedures, a perfect homogeneity is assumed both for microstructure and for texture, which is generally not observed experimentally. For this reason, the authors have proposed in recent years to combine simulation and experimental observations; the calculation starts from the real microstructure characterized by TEM or by OIMTM. The first simulations of this kind carried out have shown that such an approach is feasible and has a great potential. These results are summarized and discussed in this paper. There are limits to this approach, related in particular to the lack of experimental data on the strain energies stored in the grains after deformation and on the energies and mobilities of grain boundaries.

The Production of aluminium is one of such industrial processes that have the potential to release great quantities of dangerous toxic material into the atmosphere. To protect the environment, the Alucam Company has put in place two collection and treatment stations. The main indicator of performance of this system is the collection and treatment efficiency. All other parameters kept constant, this efficiency is proportional to the fume flow rate at the chimney. But the key parameters to control in case of variation are poorly mastered. The collection efficiency of the treatment stations can deteriorate at any moment without any successful intervention to bring back the situation to normal. This article presents the first part of a research work which intends to solve this problem of variations in the flow rate by increasing the fume flow rate and controlling the system within specified limits. We use a Continuous Improvement Methodology which involves the use of Six Sigma tools at the completion of the analysis phase of which we get the fundamental causes of the low performance.

Copper single crystals with the {110}[001] initial orientation were cold rolled and subsequently compressed in a channel die with the new direction of plastic flow parallel to the former transverse direction of rolling. The texture formed during subsequent recrystallization showed components which were not characteristic for the texture of the deformed matrix. Shear bands were formed after the change in the direction of plastic flow. Recrystallization commenced within shear bands and proceeded by the growth of selected grains into the deformed matrix. Measurements of the local crystallographic orientations indicated that the processes predicted by the theory of oriented growth played an important role in the formation of recrystallization textures. The orientations of the fast growing grains could be produced as a result of the formation of recrystallization twins.

The recent projects and the new EAF orders indicate a newtrend in the furnace design proposing very big electric arcfurnaces. Concast, after the first successful installation in2003 of the 180 t EAF in Icdas, wants to reproduce the reallyoutstanding performances of this EAF with the new 220 tEAF producing 320 t/h. The equipment installed and thefurnace design will follow the “Ultra High Chemical Power”EAF indexes.
An analysis on the basic engineering parameters and theextrapolation of its performance are presented.

Within the framework of a 3.5 million tons production of the Chertal steel plant, the RH unit and the new strand caster will produce about 1 million tons of ULC steel dedicated to automobile body applications. Therefore, some modifications at the RH were decided in 2000. This paper will be articulated in two parts: in the first part, we will present the results obtained with the modified RH installation: decarburization and metallurgical achievements as well as steel reheating capability and performances of the burner. In the second one we will present the new casting working point and focus on the quality results of the RH-CC4 production line.

Artefacts of World War I were studied to better understand iron corrosion phenomena in clay soils. The identification of their two corrosion layers by Raman spectroscopy highlighted iron oxides and oxy-hydroxides. Electrochemical experiments confirmed the porosity of the external layer, and the protective role of the internal products. The influence of the burial environment on the corrosion rate was also proved.

Low slag volumes favour high productivities. In the case of Sidmar, the burden consists of more than 90 % sinter. The iron content of the sinter has been optimized. Slag volume is thus reduced and productivity between 65-70 tHM/m2.24h is achieved. At high pulverized coal injection rates, the residence time of the coke increases substantially and a higher degree of degradation is to be expected. Therefore, a careful monitoring of the coke and sinter quality is of prime importance. This paper describes the coke and sinter quality used in the Sidmar blast furnaces to control permeability of the furnace with long term PCI rates of 180 kg/tHM and coke rates around 300 kg/tHM. A global quality index has been defined which is well correlated with the blast furnace productivity. Sidmar believes that the quality requirements of the burden can directly be linked with the requested productivity and that good operational practices are necessary for optimization of that productivity.

The European Waste Framework Directive (2008/98/EC) explicitly specifies the hierarchyfor waste management: prevention, preparation for re-use, recycling, other recoveryactions, disposal. When selecting waste management options, this waste hierarchy should befollowed. A deviation can only be justified by Life Cycle Thinking (LCT) on the overallimpacts. The application of this principle in the Flemish waste management practicetriggered the need for evaluation of treatment options for several waste streams.Alternative treatments were evaluated for waste batteries, used frying oils and waste oil.The evaluation methodology combined life cycle assessment with technical and economicalviability criteria. These cases show that LCT does not allow to establish a “generalpriority order”. In each case reasons for deviation from the standard waste hierarchycould be given, but also none of the evaluated options can be considered as the best. Theevaluation showed that the priority is largely dependent on location-specificcharacteristics of inputs, outputs, processes and installations and that the establishmentof local and global environmental priorities always implies a value choice. In thispresentation, we will present the results of the three cases and provide a methodologicalframework for life cycle thinking in waste management policy.

New glassy, crystalline and glass-crystalline materials from the GeSe2-Sb2Te3-CdTe system are synthesized by melt quenching technique. Using the results of the performed syntheses, X-ray diffraction analysis and scanning electron microscopy the glass forming region within this system is outlined. It lies partially on the GeSe2-Sb2Te3 and GeSe2-CdTe sides, as glassy samples are obtained up to 32.5 mol % Sb2Te3 and 27 mol % CdTe, respectively. Some assumptions about the structure of the samples are made on the basis of the results from the XRD investigations.

In connection with the increasingly severe environment regulation, VOEST-ALPINE Industrieanlagenbau (VAI) has developed the WETFINE system, which allows to reduce the emissions from sinter, pellet, waste incineration plants, etc. to previously unattained levels. The key element of this system, a wet electrostatic precipitator, removes not only fine dust particles from the offgas stream, but also dioxin and furan, as well as SO3 compounds.

Ultra and Very High Strength Steels (UHSS, VHSS) solutions are proposedby ArcelorMittal to meet front, side, rear and rollover crashrequirements. UHSS and VHSS steel monolithic solutions havestrongly progressed crash safety and lightening. Another steptowards higher performance is afforded by UHSS and VHSS TailoredWelded Blank (TWB) configurations.Three parts are analysed that participate actively in vehicle crashworthiness: sidemember, B-pillar reinforcement and front-end bumper.A comparison between monolithic solutions and TWB solutionsis presented, in order to determinate the extra gains (i.e. masssaving, energy absorption) that a TWB solution can offer.

Low temperature degradation (LTD) of iron oxides was investigated with the aim ofunderstanding how natural iron ores degrade under different conditions. Minimisation ofthis degradation would increase the acceptance level of natural iron ores as feedmaterials without prior beneficiation. In addition to temperature and reduction gascomposition, sample positioning in the reduction furnace and sample’s original weight werealso found to influence LTD. Samples placed in the top reaction zone of the furnace, whichhave the first contact with the reducing gas, were found to degrade 1.5 times more thanthose in the middle and bottom reaction zones. In addition, they presented a wide range ofsize in the disintegrated particles than those in the middle and bottom reaction zones.Furthermore, the samples with an original weight equal to or greater than 5 g, had adisintegration extent of less than 10%. Therefore, if the reduction gas comes into contactwith a certain material first, before contacting the iron oxide, it may serve to reduce onLTD during reduction. Furthermore, in laboratory conditions, the occurrence of lowtemperature breakdown of the natural iron oxides can be minimised by using samples with anoriginal weight equal to or greater than 5 g.

Over the last decades the steel industries worldwide haveevolved more or less independently from each other, inthe EU and in North America in particular. A competitivecomparison of two different Basic Oxygen Furnace (BOF)maintenance operations is presented, discussing various costfigures in a theoretical case study.

Two different approaches are available to reduce the mass of automotive steel wheels. The traditional approach is based on the use of high resistance steels that allows a thickness reduction of the rim and disc. A mass reduction up to 25 % can thus be obtained. A different approach allows a larger mass reduction with a more drastic change in the wheel production technology. One possibility is to use laser welded blanks to feed the existing manufacturing lines. Another possibility is to implement a combined spinning and rolling of the rim. These new steel solutions allow a mass reduction up to 50 %. Indeed they allow adjusting precisely the steel thickness and properties to the local service conditions. Finite elements calculations have been carried out to assess the static and dynamic behaviour of the new wheels.

This paper presents the experience that EKO Stahl has gained with the blast furnace injection of plastics and animal fats as alternative reducing agents since 1993. The specific pieces of equipment that have been designed and implemented for handling, storing and injecting these substances into the blast furnace tuyeres are described. The parameters that allow line stability and the overall effects on blast furnace operation are reported.