This communication presents experimental observations of plastic deformation in submicronic metallic multilayers. As the length scale decreases down to the nanometer range, we evidence a major change in deformation mechanisms, plasticity becoming less localized as in traditional slip bands of dislocations. AFM and nanoindentation techniques are used in conjonction with more standard techniques to characterize plastic deformation.

After a short historical review, this paper recalls the successive steps of the life prediction of single crystal turbine blades, paying attention to a proper modelling of the material, to the mechanical aspects in the blades, and to the boundary conditions. The code built around the FE solver ZéBuLoN is now able to predict crack initiation by post-processing of the 3D elasto-viscoplastic computations.

The heavy steel plates (100 - 300 mm) require a good geometric stability during the manufacturing operations by end users. This stability depends on the residual stress state inherited from the manufacturing process. This residual stress state is assessed by an ultrasonic testing method : the acoustical birefringence. The first tests carried out on representative heavy plates allowed to define the most suitable measurement configurations and to identify the residual stress states that could generate shape defects. Then, this method was applied to industrial heavy plates with success.

Copper single crystals with the {110}[001] initial orientation were cold rolled and subsequently compressed in a channel die with the new direction of plastic flow parallel to the former transverse direction of rolling. The texture formed during subsequent recrystallization showed components which were not characteristic for the texture of the deformed matrix. Shear bands were formed after the change in the direction of plastic flow. Recrystallization commenced within shear bands and proceeded by the growth of selected grains into the deformed matrix. Measurements of the local crystallographic orientations indicated that the processes predicted by the theory of oriented growth played an important role in the formation of recrystallization textures. The orientations of the fast growing grains could be produced as a result of the formation of recrystallization twins.

The surface quality of hot rolled low-carbon steels may be affected by their copper content when it exceeds 0.3% by weight. At high temperature (more than 1200 °C), a large part of the non oxidized copper is occluded into the primary scale and hot shortness phenomenon is prevented. At lower temperature (around 1000 °C), surface cracking may occur because Cu enrichment at the scale/steel interface cannot be avoided. Then the running risk depends on time and respective contents in Cu, Ni and Sn.

If continuous casting mould slag has been the subject of many studies, this is not true for lubricating oils. Actually, there is a significant potential for progress through formulating these lubricants in order to make the industrial process more reliable and to improve both the operating conditions and the product quality. Specific laboratory tests have been carried out in order to understand the oil behaviour at high temperature. The lubrication mechanism has been further studied with the help of high-speed visualization of the phenomena occurring at the meniscus level during the industrial continuous casting of bar products. The results make it possible to better understand the mechanisms of oil lubrication and to precise the mechanisms of the formation of the first solidified steel shell along with the formation of solidification marks and solidification hooks. This should open the way for the development of new lubricants.

The production of new steel grades - such as dual phase and TRIP steels - requires improvements to both process and equipment of continuous galvanizing lines. In particular, progress has to be obtained in cooling technology in order to get the desired mechanical properties. This paper presents a study of design parameters allowing the optimization of fast gas multi-jet cooling systems. The thermal study involves the application of infrared thermography and three-dimensional numerical simulations. Furthermore, a dynamic study is performed in order to reduce steel strip vibration.

This paper presents a portable condition monitoring system named MAPREX which was developed as result of the cooperation between the University of Oviedo and Aceralia inside of a research project funded by the ECSC - Steel RTD Program. The system integrates powerful monitoring and data visualization techniques based on the Self Organizing Map (SOM) algorithm. In this paper is described in detail the system architecture and performances, visualization techniques implemented and an example displaying real data from a 6,000 kW DC motor of a hot strip mill rolling stand.

The structures for the open car parks are an important market for the steel construction. However this market was not available in France due to very severe fire resistance requirements. Thanks to the development of fire engineering methods and to the approval of the authorities, some steel open car parks have now been built in France. This paper will describe the different steps which have enabled this change.

This article describes the study of the impact of aqueous discharge from the Fos-sur-Mer steelworks on the Gulf of Fos on the shores of the Mediterranean sea. Such a study provides information on which to base prioritization decisions for environmental action: for example, the eutrophication power of the nitrogen-bearing effluent from the coking plant led to the addition of a cleaning system operating by nitrification/denitrification.

The microtexture components of `brass-type' shear bands developed by plane strain compression in twinned C-{112}<111> oriented silver single crystals have been characterized in detail by SEM/EBSD. The twinned matrix exhibits three different reorientation tendencies : 1) a general lattice rotation of the twinned matrix towards the {111}<112> position ; 2) a crystal lattice rotation, within the shear bands, around TD towards {110}<001> which favours the operation of two highly stressed coplanar slip systems of {111}<101> type ; 3) the formation of near S-Brass {123}<634>-{011}<112> texture components by non-equilibrium slip within the shear bands. In low SFE materials the strong intensities of these components result from a saturation of the microstructure by shear bands.

AFM microscope is used here as a surface forces apparatus at the nanometer scale. We show through several examples that the curves forces (nN) vs. distance (nm) obtained are the physico-chemical signature of the interacting surfaces. From such a curve, chemical, frictional (mobility) and mechanical top surface aspects can be studied.

In the model presented, phase transformations in steels are described using thermodynamic and kinetic laws at the scale of an austenite grain. A single geometric treatment leads to the final transformed fraction. The effect of composition, temperature path and austenite grain size is taken into account. The predictions of the model are compared with experimental results concerning different steel grades. The results obtained for ferrite, bainite and final ferrite grain size are encouraging.

Drying and curing procedures of both organic and inorganic coatings by high frequency induction heating have been developed on a pilot scale. The furnace has been integrated in a continuous coating pilot line that includes a decoiler, a welding machine, a roll coater, convection furnace and a wind up roll. Thus, the complete coating process, including post treatments can be simulated, in particular for automotive applications. The first results obtained on organic and inorganic coatings with this fast curing procedure are presented and compared to those obtained with convection furnaces.

Since the 1980s steel has been more and more used in the design of bridges in France and this material cannot be ignored by anyone involved in bridge construction. Cost reduction has been the main incentive for the design of bridges with steel. Then steel was also attractive for architects thanks to its modern aspect and its flexibility, which offered them great opportunities to follow their imagination and their aesthetic feeling. By submitting some of Baudin Châteauneuf's recent references, the author shows all the advantages of using steel in the fabrication of 21st century's bridges.

After the commissioning of its vacuum degasser (RH-KTB) in 1998, Companhia Siderúrgica de Tubarão (CST) started the development of slabs to be applied as high value added products, such as ultra-low carbon steel grades (ULC) for automotive applications. For this purpose, it was necessary to promote the development of a quality design system, encompassing all stages of steel manufacturing and slab casting at CST, as well as the steps of finishing rolling and coating. This paper describes the methodology for development of ULC steels at CST together with the company Sollac-Lorraine emphasizing the interchange of technical information aiming the continuous improvement. In this way, the results of the end product surface inspection are correlated with the technical parameters of steel production, including the quality events of steel refining and casting, as well as the slab conditioning.

The paper has compiled the actual status for grades X80 and X100 from a point of view of a plate manufacturer. An outlook for a possible extension of feasibility and further development is also given. It can be summarized: 1) plates for gas transporting pipes with strength level of grade X80 are nowadays available up to 25.4 mm and can be produced with the same reliability and reproducibility as lower grades; 2) extension of grade X80 to higher plate thickness even in combination with very low design temperature is practicable; 3) during development stages of grade X100 different approaches has been applied. The current preferred approach to produce plates for pipes with design temperature of 0 °C makes use of a low carbon content in combination with a medium carbon equivalent. So called HACCII process is applied to produce these plates. Plates in thickness up to 20 mm for pipe diameter up to 3611 (~914 mm) have been produced with adequate properties; 4) further development is required and started to extent grade X100 to higher thickness, higher pipe diameter and lower design temperatures.

This study concerns the influence of certain metallurgical factors, like the addition of a mixture of rare earth metals (mischmetal) and of overheating, on the microstructure and the tensile properties of alloy A319-2 (Al-Si-Cu with 0.4, 0.8 and 1.2% iron) The new phase linked with mischmetal has a needle - and/or platelet - shape as the β-iron phase and impedes the flow of the liquid metal during casting, thus creating porosity. The different types of particles present in the microstructure remain after the T6 thermal treatment. In the alloys containing 1.2% iron, the length of the β phase and mischmetal particles is slightly smaller than in the alloys with 0.4% Fe or 0.8% Fe, after the addition of 5% mischmetal and overheating at 950°C. This explains the better tensile elongation of the 1.2%Fe-5% mischmetal alloy cast at 950°C instead of 750°C. UTS and yield strength are decreased by the addition of mischmetal but are slightly improved by overheating. Overheating at 950°C decreases the yield strength only in the 1.2% Fe-0% mischmetal alloy.

Roughness is a fundamental requirement when it comes to galvanizing sheet metal for making cars. Segal worked with Alstom and DMO to develop a measuring apparatus that makes it possible to monitor the Ra roughness factor at every point and throughout the process. The new system has been installed on the Segal galvanizing line. Two measuring heads (WINDIS) with travelling system have been installed, one on each side, after the skin-pass allowing a continuous measurement of the roughness. Alstom roughness control system is composed of an Alstom HPC controller linked to Windis and PC computer. The roughness measurement system has been in operation for a few months and the results show a very satisfactory correlation of Windis measurements with the manual measurements carried out in the laboratory.

Samples of three different stainless steel types have been nitrocarburized under typical industrial conditions: an autenitic Cr-Ni-Mo steel, a 28% Cr-Ni-Mo super-ferritic steel and a duplex ferritic-austenitic steel. The obtained nitrocarburized layers were studied by optical, electron scanning microscopy, energy-dispersion analysis (EDS), glow discharge optical spectroscopy (GDOS), X-ray diffraction and hardness measurements. The properties of these layers are compared and the results are discussed.