In spite of an extensive bibliography available, the solubility limit of carbon in ferrite is still uncertain (between 50 and 100 ppm at 600°C for example), and this is not sufficient for the improvement of steel processing. Therefore we have tried to establish as accurately as possible the solubility of carbon between 500 and 750°C in a low carbon aluminium killed steel using a thermoelectric power protocol, which enables to calculate the amount of free interstitials in a ferritic matrix from the amount of interstitials that segregate on dislocations after strain. The solubility limit has been determined at ± 2 ppm between 550 and 730°C, and described by the relation: C(%wt) = 6.63 exp(-11.8 kcal/mol/RT). At a time when metallurgical phenomena are more and more simulated, we believe that a similar procedure should be used for other experimental studies providing basic data for modelling.

The rotating lance, tested in the CaO-Mg and CaC2-Mg processes,promotes a 20% and 30% increase, respectively, in the desulphurizationrate, a 50% reduction of temperature drop, and a reduction ofmetal splash occurrences. A criterion was developed that takes intoaccount the equipment dimensions and the mass flow rates of gasand desulphurization material, with the objective of transposing theresults obtained at Usiminas steel shop n°1 desulphurization station,to other industrial plants. Furthermore, it allows simulations to bemade with the objective of optimizing the pig iron desulphurizationprocesses that use the above mentioned materials as desulphurizationagents.

The demand for improvements in surface quality and increased productivity in industrial cold metal rolling requires a good understanding of lubrication mechanisms. The limitations are due to boundary friction, controlled by the physico-chemistry of lubricant additives. The phenomena are complex and require a simplified approach. Consequently, a new method was developed by using an UHV tribometer associated with surface analytical tools to simulate the molecule chemical reactivity toward surfaces.

The MRS-100 system combines at the same time the simplicityof a linear sliding gate and the advantages of a round plate.This sliding gate is based on 3 innovating approaches: a slidinggate built around a refractory plate, a mechanism that avoids thecracking of plates and finally, an optimisation of the round platethrough a programmable sequential rotation at the ladle stand.This MRS-100 system leads to a safe use, an improvement of thetasks at the working station and a reduction of the user costs.

From his own experience, the author discusses the need of Metallurgy for theoretical models and their limits. The development of simple but less accurate models has provided a semi-quantitative approach of many complex metallurgical phenomena that has proven useful to orientate research as well as to afford interpretation-based prediction. Such models can be validated within a narrow range only. These approximate models could be substituted for by elaborated and comprehensive calculations that would provide reliable predictions with the help of ever more efficient computers. It remains a difficult task to take satisfactorily into account every internal parameter and boundary condition of a global system. Furthermore, any new observation requests another calculation that gives a clear picture but no comprehensive understanding of the underlying phenomena. Combining experiments, interpretation and prediction modeling along with few dedicated calculations may eventually allow further progress in such a complex domain as Metallurgy.

The goal of this study is to empirically investigate the major hot rolling processparameters affecting the yield strength, ultimate tensile strength and strain-hardeningexponent of Nb-microalloyed steel sheets. The parameters considered were the roughing,finishing and coiling temperatures. Three levels for each parameter were used to develop amodel relating the process parameters to mechanical properties. By applying the responsesurface methodology, analysis of variance was done to determine the mathematical modelsrelated to each response. The results indicated that decreasing the coiling and finishingtemperatures significantly influenced the mechanical properties. Also, the modelspredicted that the maximum yield strength, ultimate tensile strength and strain-hardeningexponent are simultaneously obtained under the following conditions: roughing temperature= 1097 °C, finishing temperature = 837 °C and coiling temperature = 580 °C. The predictedvalues were close to the experimental values, indicating the suitability of themodels.

When producing ultra-thin hot strip, the yield and economy depend on achieving narrow geometrical and material properties fulfilling the increased customers demand. In production, the correct measurement of the strip properties is necessary. This paper gives advanced measuring and control techniques for the parameters concerning thickness profile, flatness profile, coil face profile, temperature profile, surface finish profile of ultra-thin hot rolled strip.

In this paper, the effect of an annealing treatment on the microstructure, mechanicalproperties and electrical conductivity of a deformed Cu-12.8 wt%Fe composite prepared bythe “casting/cold working” process is investigated. The Fe filaments exhibit the shapecharacteristic in the as-drawn composite as the annealing temperature is lower than 500°C. When the annealing temperature is above 500 °C, the Fe filaments undergo theinstability process in terms of boundary splitting, coarsening and breakup gradually. Thetensile strength gradually decreases with increasing annealing temperature due to thecoarsening of filament spacing. The work hardening for the composite annealed above 600 °Cis slower than that annealed at a lower temperature. The electrical conductivity reaches amaximum of 60%IACS at a temperature of 450 °C for one hour of annealing, and it furtherincreases with increasing annealing time at 450 °C to reach a plateau of 68% IACS. Thecurve between the tensile strength and electrical conductivity under different annealingprocesses indicates that the optimum annealing temperature for the Cu-Fe composite is 450°C.

The common experimental methods used in the laboratory for the study of corrosion-fatigue are based on the evolution of global mechanical and electrochemical variables in relation with environment, mechanical loading or microstructure. For a better understanding and modelling of the physical-chemical processes involved in crack initiation and propagation, it is necessary to make use of techniques giving access to quantitative informations at local scale. Recent results concerning the breakdown of passivity, the morphology and the growth kinetics of potential initiation sites, the corrosion processes at crack tip and quantitative fractography are briefly reviewed.

The finite difference method of the low-alloy wear-resistant steel quenching process wasstudied. The temperature field and cooling rate variation of thickness of 45-mmwear-resistant steel (NM450) were calculated for different quenching practices. Themicrostructure and hardness of quenched plates were examined. The results indicate thatwhen quenching started, the cooling rate was highest on the subsurface and decreasedgradually until the center of the plate. However, as the quenching progressed, the coolingrate distribution along the plate thickness was reversed. The cooling rate increasedlinearly when the heat transfer coefficient (HTC) increased from 0–10 000W/m2 K, and then the speed gradually slowed down until achieving the maximumcooling rate. Close to the plate mid-thickness, the maximum cooling rate was easilyreached. Compared with high-pressure (HP) quenching and low-pressure (LP) quenching, underthe HP + LP continuous quenching mode, it is possible to obtain a high critical coolingrate in the temperature range of 900 °C–400 °C and small temperature difference betweenthe surface and center below 400 °C. The microstructure and hardness distribution on theplate surface for the HP + LP quenching mode indicated 100% martensite on the surface andmartensite with a little granular bainite in the plate center, while the hardnessdifference in the entire steel plate was less than 7%. This study provided guidance forthe formulation and optimization of wear-resistant steel.

The components for electronics and electrotechnics are usually classified in two families with similar market shares: the “active” components and the “passive” components. The aim of this paper is to analyze and to describe a range of ceramics passive components. The materials properties and the resulting service properties of ceramics parts are presented. This presentation is then illustrated with some significant examples of ceramics components.

Le but est d’innover dans le domaine des liaisons au sol en remplaçant une traverse d’un essieu arrière en acier à haute limite élastique par une traverse en matériaux composites : Fibre de verre et Epoxy; tout en conservant les mêmes fonctions qui sont : assurer une rigidité de torsion, lier et maintenir en position les bras de suspension, résister aux sollicitations mécaniques du cahier des charges (nid de poule, choc trottoir, ...), reprendre les points de fixation du bras de suspension. Cette étude tient compte de la problématique de la grande série : minimiser le nombre de pièces, géométrie simple, procédé de fabrication simple avec des cadences élevées, facilité de montage. La démarche employée est la suivante : étape de présélection et intégration des profilés dans le modèle numérique, choix de l’empilement du composite et optimisation, choix d’une solution, conception des interfaces, réalisation d’un prototype. Le gain de masse est significatif puisque la traverse composite avec fixation ne pèse que 3,9 kg à comparer avec les 12,4 kg de la traverse initiale.

In Europe about 600,000 tons of dusts are generated in EAF steelmaking. Valuable metals like zinc, lead, chromium and nickel are recovered from these dusts by external processors, usually. In the past, only few attempts on internal recycling have been made. Within a Brite EuRam II project, the economical and ecological benefits of the internal recycling of EAF dusts from engineering grades steelmaking have been documented. Recent investigations are dealing with the internal recycling of EAF dusts from high-alloy steeImaking, aiming at the recovery of chromium and nickel as well as at an improved foaming of the slag.

C-Mn steels and associated welds are susceptible to Dynamic Strain Ageing (DSA). In this case, fracture toughness shows a minimum when the temperature increases from 20°C to 300°C. After a literature review, the results of J - R tearing resistance tests, characterized by crack initiation resistance J$_{0,2}$ and tearing modulus dJ/da relative to a base metal (A48 French standard steel) and Manual Metal Arc deposited metals are presented and discussed. The decrease of both crack initiation resistance J$_{0,2}$ and tearing modulus dJ/da is related to the DSA sensitivity of the material. A simplified engineering method based on the evolution of the Ultimate Tensile Strength versus temperature and a method of J$_{0,2}$ determination according to a local approach model of ductile fracture are proposed to predict the maximal drop in tearing resistance exhibited by the materials around 200°C as a function of ageing sensitivity of the product.

The Research Fund for Coal and Steel (RFCS) was established in 2002 to contribute to thecompetitiveness of the European Coal and Steel sectors by supporting collaborativeresearch, pilot and demonstration projects. A Monitoring and Assessment exercise of theRFCS programme covering the period 2003–2011 was carried out by an Expert Committeecomprising four coal and six steel experts appointed by the European Commission. Theassessment exercise involved the analysis of the 198 projects completed during thisperiod, with special emphasis on the benefits for beneficiaries, Sectors and Society.Based on actual fact and figures provided by the project partners, it was established that1 euro spent in the project budget delivered a benefit of about 2 euros for the projectpartners. Extrapolated at the level of the coal and steel sectors with very conservativeassumptions, the potential benefit of the projects was estimated at about 700 M€/year. Tocapture this potential benefit, additional efforts and budget must be spent at the companylevel for implementing the relevant technological solutions.

In multiphase materials, X-Ray Elasticity Constants (XEC) depend on the nature and volume fraction of each phase constituting the polycrystal. These XEC play a leading role during X-Ray diffraction stress analysis. Self-consistent scale transition models have been developed in order to simulate the XEC characteristics of several two-phase alloys. This work makes possible the quantitative study of the influence of the second phase on the results of X-Ray stress analysis.

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.

ULCOS is a large European research project that aims toidentify and develop technology that could enable a drasticreduction in CO2 emissions from ore-based steel production.The IRonMAking flowsheeting model (IRMA) has madea vital contribution to one of the ULCOS subprojects, asIRMA models were used to evaluate the economics andCO2 reduction potential of a large number of alternativeironmaking routes.
IRMA is a software tool that allows for the use ofthermodynamic data relevant to iron- and steelmaking in aflowsheeting environment. It was developed by Corus to serveas a dedicated, flexible and accessible tool to evaluate andcompare a wide range of ironmaking routes.
IRMA can be used to calculate consumption figures, productquality and the occurrence and significance of emissions.IRMA can do this for a wide range of operating conditionsand raw material compositions.
IRMA is currently being used for benchmarking, design andpilot plant development of the ISARNA process, which wasdeveloped in the context of the ULCOS project. ISARNA isone of the four process routes that have been selected forfurther development within ULCOS.

Tests were performed on austenitic stainless steels. In order to investigate thermal fatigue resistance of quasi-structural specimens, test facilities enforcing temperature variations similar to those found under the operative conditions have been developed. Multiple cracking networks similar to those detected during in-service inspections have been reproduced. Experiments and simulations deal with crack initiation and crack growth. In the case of multiple cracking simulation, a Skelton's modelling has been used. A shielding effect between cracks is evidenced. It leads to a dramatic reduction of crack growth rate. Such effect is also crucial for the crack network stability under additional loading.

Single crystals of the low stacking fault energy Cu-2%Al alloy, with initial orientation {112}<111>, have been deformed by compression in a channel die at 77 and 293 K. Microstructural and microtextural aspects of the formed brass-type shear bands were analyzed. Experimental techniques included TEM, SEM, optical microscopy together with SEM/EBSD and TEM/CBED microtexture measurements. The crystals first rotate by slip, then transform their orientation by deformation twinning. As shear banding starts, a strong increase of intensities near the Goss {110}<100> position is observed, and this process is connected with the rotation of twin lamellae within shear bands. At the TEM scale a second weaker component is noticed. Outside the bands, the twin-matrix lamellae rotate differently and the material reorients to {111}<112>.