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.

VAI-Q Strip is a quality control system, based on physical-metallurgical models, for hot-rolled strip. This joint development of VOEST-ALPINE Industrieanlagenbau and VOEST-ALPINE Stahl Linz allows the automatic on-line control of the mechanical properties using very accurate prediction methods. Since the beginning of 2000, an extended version of the system is in operation at VOEST-ALPINE Stahl Linz and very good quality results, as well as cost savings, have been achieved.

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.

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.

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.

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.

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.

Refractory castables containing alumina-magnesia/self-forming spinel(MgAl2O4) are used in impact pads of steel ladles in steelmakingprocesses. In order to understand the wear mechanisms of refractory materials, severalrecipes were tested from a corrosion, slag resistance and thermal shock point of view. Theresults show that the corrosion is extremely limited at the slag/refractory interface forall cases. Nevertheless, for higher cement alumina content castables, the formation ofcracks is observed in refractory castables into which slag can penetrate. The slag reactswith the alumina to form a new phase such as hibonite (CA6) and calcium dialuminate (CA2).The volumetric change of these reactions involving CA2 and CA6 lead to the apparition ofmacro-cracks. Thus, the penetration of slag and steel are increased, causing hotmechanical properties to degrade. For lower cement alumina castables, the formation ofmicro-cracks is avoided by controlling volume expansion. Thus, the slag deposit reactswith alumina grains and the matrix at the slag/refractory interface to produce amonomineral layer of hibonite. In this way, the monomineral layer acts as a barrier andlimits the penetration of slag and steel into the refractory lining. Thus, to increase thelifetime of refractory castables containing alumina-magnesia/self-forming spinel, it isadvised to control volume expansion in order to avoid the formation of cracks and limitthe penetration of secondary metallurgy steel ladle slag.

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.

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.

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.

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.

In this paper an extension of the sintering method at atmospheric pressure, already used for tool steels, is proposed for prealloyed duplex stainless steel powders. A wide temperature range is tested and the effectiveness of boron as activator of the process is investigated. In all the samples no evidence of liquid phase is observed ; the sintering process allows full density in case of no boron addition and it occurs by solid phase diffusion, enhanced by the presence of two phases, austenite and ferrite : this makes needless to add boron as activator. We obtain density and hardness values comparable with the “as-cast” ones, isotropic phases structure and γ/δ ratio of about 50/50 for the best sintering temperature (1150 °C).

The blow-in of CSN blast furnace n°3 in 2006 is reported with a focuson a large solidified salamander that had to be tapped. Analyticaland finite element models have been created to predict the expansionphenomena. The predicted values are compared with the hearth shellstress and strain measurements executed during the blow-in.


The results achieved with the COREX plants presently in operation show that this technology is a true alternative to the conventional blast furnace. With the experience gained from these plants, continuing developments have been made for the COREX process itself (recycling of steel plant wastes and use of other raw materials), for the equipment design and in the area of investment costs and profitability.

The recent decrease in Blast Furnace production as well as changes in raw materials andprocess conditions has produced an increase in the silicon and phosphorus contents in hotmetal. This situation increases the probability of slopping and fume emissions duringconverter blowing because of the large volume of highly viscous slag. To carry out thesilicon oxidation and dephosphorization steps, a double slag practice has to be used. Thefirst slag is rich in silicon and phosphorus and has a low basicity. The first slag isremoved. Then the second slag is formed; this low-viscosity slag is subject to the strongagitation created by a high decarburization rate. The second slag is characterized byhigher CaO and phosphorus contents. These conditions yield a better dephosphorization atthe end of the blow. In order to implement the double slag practice, the converter controlsystem was modified. The changes included the design of the lance blowing pattern, theflux additions, the static control, and the logic of the gas collection and cleaningsystem. For a silicon content larger than 0.60% in the hot metal, the results show asignificant reduction in the fume emissions and in slopping, a lower flux consumption, andopen up the possibility of working with iron ore with higher phosphorus content.

The reasons of the success or phaseout of an industrial process remain mysterious. The history of the Perrin process allows to analyze this problem. After having described the process and the physical-chemical mechanisms underlying it, the author presents the good results obtained for the dephosphorization and the deoxidation of liquid steel and the problems which had to be solved in the case of desulphurization. Different aspects of the application of the process are discussed and different views on its adoption by steel producers are compared.

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.

Les métaux liquides sont envisagés pour des applications très variées comme les cibles de spallation, les réacteurs nucléaires de génération 4 ou les futurs réacteurs de fusion. Des recherches sont actuellement menées sur l’interaction des aciers, seuls matériaux de structure compatibles, avec les métaux liquides comme l’eutectique plomb-bismuth ou le sodium. Dans ce problème de vieillissement des matériaux, on s’intéresse tout particulièrement aux problèmes de corrosion, de mouillage et de rupture induite par l’interaction avec le métal liquide. Cette revue reprend quelques éléments de la compréhension actuelle des ces phénomènes.