An experiment of continuous casting with ultra-high frequency electromagnetic field was carried out at No. 4 commercial caster at Kobe Works. It was confirmed that the durability of a slit mould was sufficient for long casting, and meniscus level was controlled precisely enough for stable casting by the level control technology using the inductance change in the magnetic system. The improvement of billet surface quality and the lubrication between the mould and the solidified shell are discussed.

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.

Production processes of integrated steel plants, mostly based on coal as an energy source, produce about 2 tons of CO2 per ton of steel. As specific CO2 production has to be decreased by 20% in the mid-term (2020), immediate action is required to further decrease the specific energy consumption. The integrated plant is not energy self-sufficient as extra electricity must be bought from outside, but on the other hand, produces an excess of process gas that has to be used within the plant. Optimisation of the use of the internally produced gases is a key issue as either they are burned at the power plant with a conversion yield to electricity of about 40% and often much lower, or might be valued in the plant internal heat exchangers with a much higher efficiency such as  ~90% in the hot stoves or  ~65% or more in the present reheating furnaces. This paper shows that using the high-value coke oven gas as a chemical reactant (for DRI production) leads to significant extra metal production. From a global viewpoint, this extra metal production is almost carbon-free, as it requires only electricity for its manufacture.

LABEIN and ACB have developed a model to predict the mechanicalproperties of the hot rolled products, considering as a first stepthe hot rolling of thin slabs on the 7 stands hot strip mill (thin slabdirect rolling) of the Sestao steelworks.
The thermomechanical model includes a thermal module and adeformation module. It is supplemented with a microstructuralmodule and a mechanical properties module. The model has beenvalidated versus industrial results. It also includes an optimizingmodule that makes it possible to define the most appropriate processevolutions to meet new product requirements.

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.

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.

The attachment mechanism of inclusions to bubbles hasbeen studied with water model experiments under turbulentcondition. Change in particle-number concentration indicatesthat the removal rate follows first order kinetics. It increaseswith particle diameters and particle contact angles.

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.

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.

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.

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.

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.

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.

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.

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.

For a HIP operation, conventional control of the process variables (T, P) is the current mode used. The process variables follow a prespecified trajectory (schedule) assumed to lead to the final quality of product. A second mode is advanced control, where on-line measurements of a product state variable enable to monitor the evolution of the product variables and if necessary to compute corrections to the schedule in order to obtain the desired quality of the final product. HIP advanced process control requires continuous monitoring of the sample density during all stages of the process and the on-line identification a process model. To this end, a dilatometer has been built for in situ monitoring densification during a HIP operation, the Ashby process model has been validated and on-line identification has been demonstrated. It is shown that advanced process control of a HIP operation can be performed in two steps : on-line identification of the process model and subsequent process path replanning. The first step can only be performed during the process variables plateau of the preset temperature-pressure cycle, and process path replanning consists of a new temperature-pressure plateau.

Les boulets de broyage ou de concassage sont des éléments de broyeurs utilisés dans lescimenteries; ils exigent une résistance à l’usure élevée sous l’action de produitsabrasifs lors de la transformation de la roche en fines particules de taille inférieure aumillimètre. Les traitements thermiques constituent une étape essentielle pourl’élaboration du boulet. Ils permettent d’obtenir des duretés et une résistance à l’usureconvenables. Les analyses structurales et microstructurales par diffraction X etmicroscopie électronique à balayage permettent de comprendre leurs corrélations. Dans cetobjectif, nous avons étudié l’influence de quelques facteurs déterminants dans cestraitements. Les facteurs considérés dans le présent travail sont : la températured’austénitisation (950 °C et1050 °C), la sévérité dumilieu de trempe (refroidissement à l’air ventilé et à l’huile) et le diamètre des boulets(boulets de diamètre 50 et 70 mm). Les résultats obtenus ont révélé la présence decarbures de type Cr7C3 répartis dans une matrice martensitique ou ferritique etque le taux de l’austénite présent dans les boulets trempés à l’air ventilé est inférieurà celui des boulets trempés à l’huile. La température d’austénitisation et la taille desboulets influent sur la trempabilité. En effet, l’écart de dureté entre la surface et lecœur des boulets de diamètre 50 et 70 mm chauffés à 1050 °C, refroidis à l’air ventilé et à l’huile,est plus important que celui des boulets correspondants chauffés à 950 °C. Une augmentation de la taille desboulets conduit à la diminution de la trempabilité notamment les boulets de diamètre 70 mmchauffés à 1050 °C.