Basically different blends are prepared in the Arcelor coke plants that incorporate coals of various ranks, LV, MV, HV, non-coking coals. A comprehensive comparison of these coal blends, within the Arcelor coke plants, has been performed using two successive approaches : characterization of each blend at laboratory scale ; coking tests performed in the CPM 400 kg Movable Wall Oven. CSR can be maintained to very satisfying values if coals entering in the blend composition are strictly selected as regards factors like rank and ashes composition. Non-fusible components decrease the coking pressure, impair the mechanical indices and the CSR. This limits their incorporation below 10 %. Industrial results confirm the effect of the addition of LV non-coking coals : the pushing forces are reduced, the flue temperatures must be increased to keep the stability of the cokemaking parameters and the coke quality is decreased.

Apart from installation of new batteries, there exist other options for keeping respectively increasing the production capacity of a coke piant. Economic and environmental requirements have to be taken into consideration ieading to very simple solutions such as heating up of old batteries which have been cooled down followed by partial hot repairs, through-wall repairs and pas up rebuilds. Modernizations with regard to anchoring systems, heating conditions and reduction of typical emissions may be implemented in most cases.

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

CST has among its priorities the sustainable development and based on it the sinter plant unit has a commitment to reduce the atmospheric emissions, by developing actions that assure the continuous improvement on process and the development of equipment linked with environmental control, and also with raw materials consumed in the process. This paper aims at showing all evolutions on the environmental control at the sinter plant, with reference to dust and SO2 emissions, and also the visibility of the plume stack.

The increase of the demand for hot metal made it necessary to anticipate the relining of Rogesa No. 4 blast furnace. At the same time, the furnace has been enlarged in order to reach a daily capacity of 6,400 t. The work has been carried out under a consortium of Paul Wurth and SMS Demag with many subcontracting companies. The performances on the site have been very successful so that the original schedule could be reduced from 99 to 90 days. At maximum there have been more than 600 people working on the site and above al1 without any accident. The total budget amounted to 60 M Euro for the furnace itself and to 20 M Euro for the slag granulation system.

The modernization of a wide-strip hot-rolling mill with the double objective of reducing production costs and satisfying the increasing demands of the market represents a lower investment than the construction of a new mill, but is connected with the consideration of highly complex aspects. The authors present three projects showing the approach used by VOEST-ALPINE Industrieanlagenbau (VAI) and the results obtained.

The 3rd octave chatter in cold rolling mills is a major issue for the industrial production of thin sheets with very tight tolerances, like packaging steels for instance. In this context, an experimental and theoretical approach, completed in partnership by Arcelor and VAI, afforded a precise analysis and innovative results, in the following fields : global on-line tandem mill instrumentation and efficient signal treatments implementation ; clear differentiation between brummer (non divergent mode) and chatter (divergent mode) ; modelling of interactions between chatter and technology (analytical and F.E. approaches) ; advanced chatter monitoring and industrial implementation.

The high corrosion resistance afforded by Zn + 5wt.% Al coatings is further improved by low level additions of Mg in the galvanizing bath. The effect of Mg additions on the microstructure and on the properties of the coatings has been investigated. Phase field modelling was used to simulate the influence of Mg on the eutectic microstructure. Experimental results on the effect of Mg on the ductility and on the corrosion resistance of the coating are also reported.

XPS and Auger spectroscopies are oflen used in several fields of activity of the steel industry that may be sorted into three items : defectology and expertise, research and development on products and process, study of metallurgical mechanisms. In these fields of activity the results, that we provide our customers with, are obtained within the frame of a "Quality insurance - Certification" approach. This approach is based on the appropriate measures taken by Arcelor Research to give customers every confidence that any error of measurement will be prevented. The few examples in this paper demonstrate how XPS and Auger analysis, performed on samples of small size to study phenomena at a nanometer scale, can be a great help to the industrial line management.