The mixed regime of lubrication is most frequently encountered in cold strip rolling processes. A model is presented hereafter. The lubrication at the interface is closely coupled with the mechanics of the rolling process. Therefore, the proposed model combines a macroscopic model of rolling (elastic-plastic slab method) with a microscopic mixed lubrication model, consisting of a Reynolds equation for rough surfaces (describing the formation of the lubricant film) and an equation for the evolution of roughness, describing the conformation of the strip surface to the roll. The bases of the model are presented and compared to models in the literature; its hypotheses and results are discussed, a few applications are given.

The leading position of ISPAT as a producer and consumer of DRI is explained. For DRI production, raw material quality and DR process conditions are important factors contributing in particular to optimize metallization and productivity. The conditions for the use of this DRI in ISPAT's steel plants are also described : continuous feeding, economic blending for residuals control, low nitrogen operation at the EAF. Increased metallization and high carbon content of DRI have positive effects on power consumption, yield, heat losses, etc. in the steel plant.

Strip rolling processes depend critically on friction and lubrication for process control as well as for strip quality. Pechiney and Usinor companies have therefore joined with CNRS (National Scientific Research Centre of France) to build an ambitious project gathering seven French public laboratories and their own research centres, Irsid and Centre de Recherches de Voreppe. The two major fields of lubrication were addressed: the formation of fluid lubricant films between rough deformable surfaces, and the formation of boundary films (tribochemistry). The final purpose was to derive a model of rolling processes including a predictive, local friction model. This issue and a future issue of Science et Génie des Matériaux present the efforts and the results of this Research Programme Contract "Materials forming: metal - tools - lubricant contact".

In connection with the increasingly severe environment regulation, VOEST-ALPINE Industrieanlagenbau (VAI) has developed the WETFINE system, which allows to reduce the emissions from sinter, pellet, waste incineration plants, etc. to previously unattained levels. The key element of this system, a wet electrostatic precipitator, removes not only fine dust particles from the offgas stream, but also dioxin and furan, as well as SO3 compounds.

The permeability of the blast furnace and in particular of its lower part, conditions its performances and its campaign duration. It is therefore essential to be able to characterize it. Several methods have already been used as radioactive tracing, coke core boring and Iiquids sampling, achieved by the tuyere probe installed on the BF 1 of Sollac Fos. Results of these measurements can be completed by gas analyses on the blast furnace radius and by gas tracing using helium, also achieved with the tuyere probe. This article presents the synthesis and shows the consistency of these various measurements.