A new on-line guidance tool has been implemented to help the mill operator with the achievement of a thickness performance that meets the ever more stringent requirements for DWI material. The tool makes it possible to analyse the causes of thickness defects that are originated by the HSM or by the tandem mill.

The development of high tensile strength steels with higher levels of alloying elements needs the implementation of operating means in the continuous casting machine to master slabs internal soundness and surface quality. In order to define optimal process parameters according to the characteristics of the different continuous casting machines and to optimize the revamping of older equipment, thermomechanical modelling of the steel slab behaviour during casting has been carried out. This paper presents the results of simulations performed to check the potential of this modelling.

To improve quality of the automotive steel grades, Posco has revamped the caster of the Gwangyang Works in 2003. The caster has beenbasically changed from curved mold to vertical bending. The caster also features new technologies such as stopper rod flow control, multimode EMS, hydraulic mold oscillator, optimized segment roll pitch, dynamic soft reduction and secondary cooling, hot slab grinding, Poscomonitoring package.

This paper reports on the Congress of the Arab Iron and Steel Union (AISU) that has been convened in Beirut, Lebanon, September 29 - October 1, 2004. Presentations dealt with the global theme of the development of the steel industry in the Arab Countries or with the technical aspects of steel production routes and continuous casting.

Innovative blast furnace operations with top gas recycling after CO2 scrubbing were numerically examined. The fully kinetic mathematical model was applied to the operations with recycled gas injections into the tuyere and stack parts of the furnace, and the top gas recycling combined with waste plastics injection. The simulation results showed that the top gas recycling decreased the reducing agent rate and increased the productivity.

In this paper, Siemens VAI presents its SmartCrown Technology package, which includes innovative solutions for the improvement of dimensional tolerances, of profil and flatness, and for the achievement of high mechanical properties of hot rolled strips. Steel producers can thus benefit from advantages in terms of product quality and cost.

An Electromagnetic Brake (EMBR) makes it possible to increase the casting speed while maintaining or even improving the product quality. For conventional slabs, the FC mould is most appropriate while for thin slabs, the ruler type EMBR is the preferred solution. The FC mould features two independently controlled static magnetic fields, one at meniscus level and another at the bottom of the mould. The upper field controls the speed flow at meniscus to prevent mould powder entrapments and the lower field reduces the penetration of the steel jets from the casting nozzle, to facilitate flotation of inclusions. The FC mould is the only equipment capable of controlling these parameters independently. It affords effective solutions to reduce pinholes, cracks and surface or subsurface inclusions. A new closed loop control of the FC mould, the EM Control, has also been developed, based upon the input of two meniscus level signals that simulate the meniscus speed. Through 3D transient modelling of the caster performance, temperatures, steel speed, meniscus level are made available. The two static fields are then adapted on-line to achieve both low penetration and a constant meniscus speed.

Discontinuous precipitation and dissolution in the Al-Zn alloy system has been the subject of many theoretical and experimental investigations that have contributed to the understanding of the different mechanisms which control them. However, many questions remain unanswered because of the complexity of the constituted phases which are affected by the rate of quenching, the amount of deformation, the temperature of homogenization and the ageing effect The purpose of this work is to clarify the effect of temperature and deformation on the mechanisms of these two reactions during ageing of the AI-15at.%Zn alloy. The techniques of analysis used in this respect are optical microscopy, X-ray diffraction and Vickers microbardness.

Energy savings are among the most important goals of steel users. But generally, the increase of Tensile Strength for a given metallurgy isobtained to the detriment of ductility. Arcelor develops new ultra high strength steel with TWinning Induced Plasticity (TWIP) effect for weightreduction and impact resistance. This product, based on manganese (Mn) alloying metallurgy, has a tensile stress higher than 1000 MPa fora total elongation superior to 50%. Properties of these new steel grades are reported, in terms of tensile and forming behaviour, weldabilityand fatigue.
Crash resistance is investigated by using a dynamic axial compression test and a dynamic three point bending test on structural componentswith closed and open cross sections. Optimised designs are presented for safety parts in FeMn TWIP 1000 and assessed againstconventional UHS steel. For each steel grade, the weight saving potential is estimated with respect to parts manufactured in high drawingability steel.


After presentation of the history of oxygen steelmaking, with special emphasis on the LD process, the numerous further developments and variants of the converter process are discussed. Finally, a tentative synthesis between electric and converter steelmaking is proposed. The article ends with considerations on the future of oxygen converter technology.

To precede the energy and environmental demands, a follow-up ofthe coke oven batteries was made, to identify the probable causesof pollutants generation and thermal losses. The results of thefollow-up of the in/out gases of the coke ovens led to a change ofthe traditional operational practices, aiming at reducing the airemissions and the energy consumption of the coke ovens.

Since its construction in 1979, the Steckel mill of the Brazilian steel producer Acesita has been modernized in successive steps in cooperation with VOEST-ALPINE Industrieanlagenbau (VAI). This continuous cooperation between the equipment supplier and the steel producer serves as an outstanding example of a life-cycle partnership.

An increase in the continuous-casting capacity of a steel mill requires either the upgrading of existing machines or an investment in a new caster. However, space restrictions may prevent the installation of a new caster within an existing steel mill. The VAI compact caster introduced in this paper is designed to enable steel producers increase their casting output and production flexibility with the installation of a highly compact caster within the restricted space of an existing steel mill. With this solution, two independently cast and controlled small-width slabs or a single wide-width slab can be cast with the same equipment.

The instrumented bars designed and patented by Arcelor Research enable precise calibration of the actuators (roll-gap, transversal and longitudinal tilting and back-up rolls) of levellers. The calibration procedure requires to stop the cut-to-length line for 30 minutes to calibrate the leveller, if no major mechanical operation is necessary. The measurement device will guarantee the pre-setting validity and the longevity of the leveller.

A numerical tool has been implemented at Arcelor Research to evaluate the influence of different process parameters on the stability of the flow in the CC mould and on steel cleanliness. The key parameter to improve steel cleanliness is hydrodynamics. It is generated in the mould and naturally unsteady, even if maintaining the process parameters at a constant value. In order to maintain a stable mould flow that allows inclusions removal while avoiding the creation of new defects, process parameters should be optimized or some actuators should be proposed and adapted. The new numerical tool affords a better understanding of the phenomena in the CC mould when some modifications or variations are imposed.

Anisothermal and isothermal oxidation tests have been used to establish correlations between growth kinetics, morphological and microstructural evolutions of NiO layers formed during the oxidation of high purity nickel. It is shown that the transport phenomena taking place during the growth of such layers are complex and a growth model is proposed, which takes into account the diffusion of cationic species (in volume and by short-circuits), the transport of oxygen and the interfacial reactions.

Data from the Rautaruukki Raahe sinter plant were analyzed with feed-forward neural networks. The resulting models were used to investigate and optimize the sinter plant production rate and the reduction degradation index (RDI) that is an important sinter quality indicator for small blast furnaces. Especially, the effects of controllable parameters such as the chemical composition of sinter, physical conditions of raw materials and factors reflecting the sintering event were studied.

The coating of thirty-four industrial galvanized samples from four different lines have been characterized by selective stripping and ICP analysis. It is shown that this analytical procedure gives consistent results. The free Al in the coating is always lower than the effective Al in the pot. This is explained by its diffusion after wiping. The Al picked up in the pot is then always lower than the Al tied up on a solidified and cold product. The difference depends on the sheet thickness which affects the cooling time.

Electromagnetic techniques attended to the development of the steelmaking process almost right from the beginning. Although their implementation requires a high level of knowledge they are quite commonly used. This was made possible thanks to close collaboration between steelmakers that implement, university laboratories, prominent among them is Madylam, and equipment suppliers. With the help of three examples, this paper shows what are the ingredients of an efficient collaboration in the field of Electro Processing of Materials (EPM).

This article describes an innovating measuring device to continuously assess the powder coverage on the whole surface of the mould in a continuous casting process. The measurement is based on the use of a thermal imager device moved along the mould. With adequate translation and rotation of the camera, it is possible to view up to 72 % of the surface of the mould. A dedicated program for images acquisition and processing displays coloured maps of the mould on which areas with poor powder coverage are clearly highlighted. With this technique, the control of the powder addition in a closed loop way, by using the analysis of the image, is possible.