An innovative modelling strategy has been developed and validatedto help the design of steel reheating furnaces. A set of complementarysimulation tools has been used to rethink the furnace concept,namely the Digit@l FurnaceTM, from the burners to the global energysystem optimisation. Several Digit@l FurnacesTM are now in operationon hot rolling mills. Advantages in terms of pollutant emissions,operation costs and flexibility have been demonstrated on site.

Previous experience achieved with two of the leading systems,namely the VAIron closed-loop expert system of Siemens VAI MetalsTechnologies and the VAIF blast furnace expert system are describedfor several installations. The advantages of both systems havesince been combined into an advanced, state-of-the-art systemreferred to as VAIron–The Next Generation. This paper outlines thestructure and highlights of this new expert system.

A quantitative method is described for the measurememnt of displacements and strains by high-resolution electron microscopy. The image is considered to be composed of periodic sets characterized by Fourier analysis. The local amplitude and geometric phase of lattice fringes can be determined in this way. The analysis of the phase distribution leads to the determination of the local lattice configuration. The method is illustrated by different examples and its application conditions are discussed.

ACB was the first thin slab casting and coiling plant in Europe, using CSP technology and up to now is the only CSP that uses steel from an electric arc furnace. The evolution of process and products in these facilities are presented from the start up in 1996 to the present situation. Particular attention is paid to the development of microalloyed, electrical and weather resistant steels, the improvements of surface and internal quality and the modifications introduced in the plant to improve productivity. Furthermore, geometrical aspects and thin gauge rolling are discussed with a view to develop 1 mm hot rolled coils.

In order to improve the blast furnaces stability and productivity, industrial trials with the aim of reducing the circulating alkali load in the furnace and tests on a laboratory scale have been performed. The mechanical behaviour (fines generation) during reduction in presence of alkalis of various iron materials loaded in the blast furnace (sinter, pellets, iron ores) has been characterized with a set of Boris trials.

Flexible production of a continuous range of profiles and sections using the same set of tool rolls is now possible with the world-unique FCF system. Developed by VAI, this technology was installed for the first time ever at voestalpine Krems, Austria. This paper presents the main design features of FCF technology in addition to production results and benefits.

This paper addresses several experimental techniques, which have been developed and validated with the aim of assessing the mechanical conditions of service-exposed primary plant components, particularly from the point of view of fracture toughness. Such techniques are based on the use of specimens of small or even miniaturized size, as an alternative to the "conventional" methodologies described by commonly used test standards.

A closed-loop blast furnace automation system was jointly developed by VOEST-ALPINE Industrieanlagenbau (VAI) and VOEST-ALPINE Stahl Linz (VASL). The system, with the tradename VAiron, makes not only the operation of the blast furnace entirely transparent, but stabilizes it also, and permits therefore significant improvements in the regularity of hot metal quality and substantial reductions in production costs. The final goal of the development is the "fully automatic blast furnace" .

This article presents the work carried out to define quality criteria of a new scrapsource for the steel industry: steel wires generated by grinding end-of-life tires. Thedefinition of this promising new secondary raw material source is perfectly in agreementwith the European Directives 75/442/CEE and 2000/53/EC, dealing with waste and recyclingof end-of-life vehicles, thus answering the environmental needs of our society.

Grindingtires generates an interesting secondary raw material (rubber granulates) but also twowastes, steel wires and textile fibers. We estimate that steel wires represent in Europe180 kt of steel every year which is not, or badly, valorized. This study showed that therecycling of these steel wires in steel mills was possible and viable, one necessarycondition being the determination of the non-metallic content remaining on the wires andkeeping it lower than 4%.

Fatigue crack propagation in a welded joint of a cablecar post hasbeen developed, based on parameters measured on real joints. Itmakes it possible to optimise the schedule for inspection of theposts.

Ce travail est dédié à l’étude de l’endommagement en fatigue polycyclique soussollicitations multiaxiales de matériaux métalliques, suivant deux objectifs. Le premierest la caractérisation expérimentale de cet endommagement, pour des sollicitations simples(traction et torsion), mais également pour des blocs de sollicitations différentes. Lesecond objectif est la modélisation des phénomènes observés incluant l’usage de lamécanique de l’endommagement.

Cette modélisation est établie dans un cadrethermodynamique, suivant une description mésoscopique de la plasticité cyclique, avec uncouplage fort des variables décrivant le dommage cristallin. La version isotrope présentéeici utilise deux variables distinctes pour décrire l’endommagement du cristal. La premièrevariable permet de considérer les effets de la dégradation du cristal sur ses propriétésplastiques, alors que la seconde est une mesure équivalente de l’usure du cristal.L’évolution relative de ces deux variables dépend en premier lieu de la part hydrostatiquedu tenseur mésoscopique des contraintes.

L’acier inoxydable 304L est utilisé dans de nombreux domaines. Cependant, il peut, dans certaines conditions, être sensible à la corrosion par piqûration. Dans cette étude, nous nous sommes intéressés aux potentialités du traitement de fusion superficielle par laser nanopulsé pour l’amélioration de la résistance à la corrosion de cet acier. Ce traitement consiste à focaliser un faisceau laser sur la surface du matériau, provoquant sa fusion quasi instantanée sur quelques microns, immédiatement suivie d’un refroidissement ultra-rapide allant jusqu’à 1011 K/s. Les paramètres laser impliquent des modifications des propriétés physico-chimiques. Nous avons notamment étudié l’influence du recouvrement des impacts d’un laser à fibre ytterbium sur la résistance à la corrosion de l’acier inoxydable 304L dans des conditions d’une solution aérée, agitée de NaCl (concentration de 30 g/L). Nous avons obtenu une augmentation du potentiel de piqûration de l’ordre de 220 mV, traduisant une amélioration de la résistance à la corrosion. L’étude approfondie des modifications chimiques et structurales ne suffisent pas à elles seules à expliquer l’amélioration de la résistance à la corrosion. D’autres phénomènes doivent être pris en compte, comme la qualité de la couche d’oxyde, tant en terme de propriétés physico-chimiques, que mécaniques.

The operation of blast furnace No. 2 started in July 1998, raising the CST yearly hot metal production from 3.6 Mt to the present level of 5.0 Mt. In July 2004, after a 6 years long operation, blast furnace No. 2 cumulated a production of 8.16 Mt, moreover ensuring good performance. The paper presents the actions that have been taken to control hearth wear, while sustaining high productivity and low fuel consumption. The results obtained are submitted to a detailed analysis with appropriate reference to the approach that has been followed and the controls that have been implemented.

A comparative study between the mineral coals used byArcelorMittal Tubarão has been carried out, aiming atdetermining complementing criteria to the current energy modelfor the mineral coals purchasing qualification used for injectionin the blast furnace. Material characterization techniques wereemployed allowing the mapping of the characteristics of thecoals which potentially affect the stability of the pig ironproduction process.


The aim of this work is to produce metallic coatings onto a steel substrate type E335 in order to hardening and improving the tribological properties of contact surfaces. In this study, two different coatings of stainless steel 18/8 and molybdenum realized with and without bond coat in Ni-Al were sprayed using a thermal flame spray technique. The microstructures of the two deposits are obtained using an optical microscope (OM), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Measures microhardness under a load of 200 g, are performed on the polished surfaces of these two types of deposits. The wear and the determination of the coefficients of friction of the two deposits tests were performed in dry conditions. A pin on disc configuration on a tribometer type TE 91 was used with different normal loads and a sliding speed of 0.5 m/s. The results showed that the microstructures obtained by OM and SEM of stainless steel present a dense and compact microstructure. It contains a low porosity and unmelted particles in comparison with the coatings of Mo. In addition, it was found that the spray-coated stainless steel 18/8 exhibited higher microhardness, higher wear resistance and significantly low friction coefficient in comparison with those of Mo coatings.

Especially in OECD countries, the reduction of primary energy consumption is a major taskto avoid further increase in CO2 emissions. Since 37% of the annual energyconsumption is related to the building sector, it is a major challenge for the future todevelop methods for significant improvement of the energy efficiency of building design,construction and operation. It has to be noted that the development of sustainablebuildings addresses both engineering and social aspects. From an engineering viewpointmethods to improve the ecologic efficiency of buildings by increasing the lifetime have tobe provided. From a social viewpoint these new approaches must take the future needs ofsociety into consideration. In addition, also governance structures and the regulatoryframework for the construction and operation of buildings need to be modified in thedirection of sustainability. The article will initially identify the major research topicsfor the development of sustainable design principles for buildings. Afterwards, structuralrequirements will be defined and translated into required property profiles for buildingmaterials. Herein, both mechanical and functional properties are of importance, so thatapproaches will be presented how to combine these properties in composite buildingmaterials. With respect to mechanical properties, new steels will have to be developedwith an improved balance of strength and ductility, so that some promising steel designconcepts will be shown. Additionally, new approaches for the failure assessment of thesenew steel types will be presented to enhance the exploitation of the characteristics ofthe innovative materials.

Freckle defects were found in electro-slag remelting (ESR) ingots, which severely limitthe development of the larger-diameter ingots. The macrostructure and the composition ofthe freckles in a low-alloy structure steel ESR ingot were investigated to clarify thefreckle formation mechanism. The results shows that the freckles in the ingot were causedby the upward solute-rich liquid flow in the mushy zone, and the composition of thefreckles corresponds to that of the liquid, with a liquid fraction of 0.36 to 0.43. Therelative Rayleigh number (Ra), a freckle criterion considering the effect of atilted solidification front, was adopted to evaluate the freckle formation tendency in theindustrial-scale ESR ingots based on the results of the experiments, kinetic simulationand thermophysical property calculation. The calculated results of Ra are in good agreementwith the actual distribution of the freckles in the ingot.

Crystallographic textures of hot rolled microalloyed steel strips fromthe thin slab direct rolling AST process is determined by EBSD. Theeffect of the thermomechanical treatment on the strip texture is analyzed,pointing out a significant through thickness gradient.

Using recent and more accurate data, the thermodynamic model of Ma and Janke has been extended to a five element system. The content of non-metallic inclusions has been investigated for two grades of duplex stainless steels after solidification. The chemical and morphological features of the inclusions were determined by SEM observations and EDS analysis for different cooling rates. The results are interpreted on the basis of the chemical-physical interactions in the Fe-Cr-Ni-Si-Mn-O system. They can be used to define the optimal oxygen potential pattern for the casting of this type of steel in foundries.

Les alliages ferritiques Fe-8 %Al possèdent des propriétés physiques et mécaniques prometteuses pour le développement et la conception de nouveaux types d’aciers allégés. Ces alliages présentent cependant des défauts de surface appelés « roping », apparaissant après l’étape d’emboutissage à froid. La formation de ces défauts est principalement attribuée à la distribution hétérogène des orientations des grains. Dans cette étude, les effets de la quantité de déformation, de la vitesse de déformation et de la température ont été examinés en utilisant la torsion à chaud. Les essais ont été réalisés à des températures comprises entre 900 °C et 1100 °C et des vitesses de déformation comprises entre 0,1 s-1 et 10 s-1. Il a été montré que deux types de recristallisation dynamique pouvaient intervenir durant la déformation à chaud : la recristallisation dynamique continue et la recristallisation dynamique discontinue.