From 1998 to 1999, an extremely intensive dioxin measuring campaign has been performed at the sinterplants of Sidmar. More than 500 measurements have been made. Several hypotheses and adsorbents have been tested for the reduction of the dioxins. Process control improvements and the use of burnt lime then allowed reducing the dioxin emissions by 85 % . For a further decrease, it was decided to build an industrial coal injection installation at the sinterplants. The present reduction of the dioxin emissions is more than 95 % and will reach 97 % in 2001.

Sollac Lorraine has two LWS bottom blowing converters. This process generates rapid skull formation on the upper part of the vessel preventing normal operation. A post-combustion lance has been installed in order to get rid of skull formation and increase the scrap ratio charged into the converter. The industrial start up, in April 2000, has shown a very good performance for skull control and also for the increase of scrap charged into the vessel.

Rotary furnaces are a well established alternative to cupola furnaces. Recent innovations in oxygas furnaces have made them the preferred choice even over medium-frequency electric furnaces in many European foundries. The article explains in what respects the rotary furnace is a new iron smelting concept, as different from the cupola furnace as the medium-frequency electric furnace.

A model of lubricated cold strip rolling is extended to the thin foil case. The model considers the evolution of asperity geometry and lubricant pressure through the bite. Friction between the roll and the asperities on the strip is modelled using the Coulomb and Tresca friction factor approaches. The shear stress in the Coulomb friction model is limited to the shear yield stress of the strip. A novel modification to these standard friction laws is used to mimic slipping friction in the reduction regions and sticking friction in a central neutral zone. The variation of rolling load, lubricant film thickness and asperity contact area with rolling speed is examined, for conditions typical of rolling aluminium foil from a thickness of 50 to 25 μm.

The condition of the coke bed in the lower zones of the blast furnace determines the nature of liquids flow into and through the hearth. Methods for monitoring the condition of deadman cleanliness and coke bed voidage at the taphole level have been developed. Influences on metal chemistry and hearth refractory heat loads are discussed. This paper also discusses strategies for management of taphole performance by application of operator guidance techniques which employ real time data acquisition and the on-line application of mathematical models of liquids removal during casting. Recommendation strategies for installed clay volume and taphole opening/closure times are discussed.

Technical improvement on clean steel in the No.3 steel plant at Wisco, China Z. Yu, W. Zheng, X. Wang, Y. Zou In recent years, a series of measures have been taken to improve the cleanliness of the steel produced in the steel plant No.3 of Wisco. The content of impurities like C, N, H, S and total O is accurately controlled. The amount and nature of non-metallic inclusions can be adjusted and their shape modified. Results obtained in the case of IF steel and linepipe grades are presented.

The main milestones of the development of the modern steel industry are recalled and the changes which have occurred during the last ten years of the 20th Century are examined in the light of the evolution of the economical context in that period (protection of the environment, energy management, development of electric arc steelmaking and of compact and efficient production units, etc.). Several trends for the future evolution of the steel industry are discussed : environment friendly technologies and operations, controlled recycling of scrap, deep modifications for the electric arc furnace, methods for reducing the emission of greenhouse gas, etc.

The principle of the FINMET fluidized bed direct-reduction process is reviewed and the two presently built installations are presented. The problems encountered at the start-up of the Port Hedland plant have been solved by modifying the process parameters. With the new operating conditions, production rate and product quality are at the desired level.

In order to improve a cold rolling lubrication model, the effects of this process on the formation and evolution of superficial layers in two alloys were studied by coupled surface and microscopy analysis. On the Al-Mg alloy, the friction on the metal asperities and their crushing provoke, by localized hardening and heating, the burying of debris in the substrate, the recrystallization of the metal within a layer of 250 nm and its recovery down to 20 μm. On the steel, the oxide layer mainly becomes amorphous and plastic, because of a high incorporation of the lubricant, and heterogeneous at the nanoscopic scale.

The topography of grain boundary thermal grooves in the Ni-rich NiAl is studied by the atomic force microscopy. It is demonstrated how the processes of grain boundary sliding and surface faceting modify the shape of the grooves. The quantitative theory of grain boundary grooving that takes into account the above complications is developed. The great potential of grooving studies for the analysis of microstructure evolution is emphasized.

General indications are first given about the purpose and the use of surface modification techniques in art. The activity in this field at the "Centre de Recherche et de Restauration des Musées de France" is then described: surface assessment, techniques of restoration, recommendations for conservation. The authorized range of scientific investigation on patrimonial objects is discussed. A methodological analysis of various surface characterization methods and surface treatments is proposed. A limited number of demonstrative examples show the application of these methods in different areas at the Louvre.

In March 2000, a new compact steelmaking plant of Suez Steel (Adabia, Egypt), erected by VOEST-ALPINE Industrieanlagenbau (VAI), has successfully been started up. With a Finger Shaft type electric arc furnace (FUCHS system), a ladle furnace and a 5-strand caster, this highly modern plant has a capacity of 600,000 t/year of structural steel billets. Since the start up, new production records are continuously established.

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" .

Recent studies have shown that in certain situations, usually described by mixed lubrication models, a continuous ultra-thin film could separate two solids, even at the scale of asperities. In this paper, the consequences of this assumption are examined in the case of cold rolling geometries. The tribological behaviour is derived from the resolution of the Reynolds equation. The influence of the rheological parameters of the lubricant and of the existence of a cavitation zone is discussed.

During the cold rolling of metal alloy sheets, the control of lubrication constitutes one of the major industrial problems. The aim of the study reported in this article concerns the rheological characterization of two industrial lubricants, under conditions close to those met in rolling. The application of EHD models then allows to calculate the lubricant film thickness, which is compared to the values measured by interferometry in a ball/disk contact.

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.

Developments in electronic structure calculations and computer performances have made it possible to perform ab-initio calculations of structural properties of materials, like defect parameters in transition metals. The values of vacancy formation and migration enthalpies calculated in this context agree with experimental data within less than 10% . Reliable self-diffusion coefficients for the vacancy mechanism can be deduced. This approach sheds new light on the so-called self-diffusion anomaly in body centred cubic metals.