In horizontal continuous casting or in meniscus free continuous casting, the appearance of corrugations or marks at the surface of the cast products cannot be related with the partial solidification of the meniscus of the free surface of the liquid metal, like in the case of the classical vertical continuous casting process. In order to find their origin, an experimental work has been carried on with two different experimental devices. The first one provides solidified metallic samples to be observed and analysed. With the other one, it is possible to directly look at the formation of the skin on the mould during the solidification of transparent organic compounds. Here, we firstly present the results of the observation of the surface of samples cast in very different casting conditions. In a companion paper, we propose a description of the formation of the marks and corrugations in terms of basic phenomena which occur during solidification.

The work presents results of investigations and microstructural analyses for Mg- SiCp cast composites. The metallographic examination shows that the distribution of SiC particles is uniform. Quantitative image analysis of the microstructure shows the magnesium grain size to be smaller and more uniform than in the base metal. The studies at the level of the interfaces suggest that the bonding between the matrix and the reinforcement is of the adhesive type. The presence of the Mg2Si compound in the composites has also been revealed. Additionally, some compounds seem to be present at the SiC/matrix interface. The performed analyses have allowed to propose a model description of the process of the formation of the Mg-SiC composite structure. Mechanical testing has shown that composites have increased YoungÕs modulus and proof stress (R$_{{\rm p 0,2}}$) and decreased impact strength.

Refractory products greatly affect steel quality and cleanliness. Some examples of interactions between refractories-slag-steel on steel desulfurization and carbon pick up in ultra-low carbon steel during the secondary treatment processes are presented. Consequences of refractory behaviour with respect to liquid steel cleanliness during continuous casting are examined : reoxidation of the metal, transfer of elements in the tundish, alumina clogging, etc. Methods for further improvements are indicated.

In order to explain and simulate the behaviour of real, complex gas-solid reactive systems, we developed a new kinetic model which describes the coupled phenomena of chemical reaction, diffusion, heat transfer and porosity evolution. The model was successfully applied to the hydrofluorination of uranium dioxide. The difference in reactivity between two dioxides has been related to their initial pore structure and its evolution.

The Dunkirk RH-OB was one of the first in Europe and started in 1984. Since the beginning, its production has increased steadily and the proportion of decarburization treatments has become predominant. This performance has been made possible thanks to investments like an increased capacity of the vacuum pump and an enlargment of the diameter of the snorkel and to improvements in the process. The carbon level and the treatment time have been reduced continuously.

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.

To clarify the efficiency of internal reduction at a continuous casting strand, a series of liquid core reduction tests with various shaped ingots was carried out, and the amount of internal reduction was determined by adding tracer into the liquid core. The result was discussed by deformation analysis, using the three-dimensional Finite Element Method. Factors influencing the internal reduction efficiency were assessed, and consequently, a regression equation to estimate the amount of internal reduction for any casting shapes and conditions was derived.

The influence of tensile stresses coupled with temperature cycling has been determined on a Cu-Zn-Al shape memory alloy that transforms above room temperature. It is shown that the application of increasing stresses during thermal cycles leads to an increasing martensite stabilization. The repeated thermal cycling with constant stress as well as slow temperature rates increase the stabilization. This phenomenon is attributed to a pinning of austenite-martensite interfaces by vacancies. This hypothesis is confirmed by the comparison of experiments with continuous and with stepwise temperature variations.

What will the electric arc furnace of 2010 look like? A Delphi study, conducted within a working group of IISI, has produced trend and contrasted scenarios that project a spectrum of furnace images. The EAF is indeed the metallurgical reactor that has the largest growth potential in the middle term, both in terms of production capacity and, correlatively, of technology evolution.

The steps of the conventional production process of stainless steel cold rolled strip are recalled, as well as the evolutions that have preceeded the design of the LC2i line. The advantages and constraints of this integrated and continuous line are outlined. The main equipments coupled in the line are described and their characteristics presented. Automation, work force training, TPM, protection of the environment have been essential features in the project.

The feed head continuous casting technology was jointly developed by CRM and Irsid for the long products. Since 1996, CRM has undertaken developments aiming at transferring the technology to flat products. Casting trials were performed on the simulator of CRM equipped with a slab mould. The results obtained, concerning as well the technological aspects as the product quality, are very promising.

C-Mn steels and their welds are sensitive to the dynamic strain ageing (DSA) phenomenon. The DSA sensitivity of different weld zones is not well known. Therefore, the influence of microstructure in the heat affected zones, the effect of post weld heat treatment and the effect of the chemical composition (manganese content) of the deposited metal were studied by correlation between tensile tests and internal friction tests (mechanical spectroscopy).

The features of the continuous hot dip galvanization are recalled and it is shown that a process avoiding the contact between the strip and immersed rolls would be a step forward. Such a process has been imagined and studied by means of a water model. Tests on a pilot galvanization line have allowed to determine conditions where no contact occurs between the strip and the zinc containing tank. Stable operation is possible for a sufficient range of line speeds and strip tensions. The advantages of this technique are being verified using a pilot prototype.

A consortium led by VAI erected for HADEED (Al-Jubail, Saudi Arabia) a new production facility for a wide range of flat rolled products, on a turnkey basis. This giant plant includes a steelshop, a continuous caster, a hot rolling mill, cold rolling facilities, as well as all necessary side installations. The project is characterized by a series of highly new technological solutions and a high degree of automation of the production process (process and quality control).