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.

Substituting used tyres for anthracite in the EAF in France and inBelgium is reported. First trials have been carried out in Lorraine in1997 in the frame of a partnership between Usinor (now ArcelorMittal), Michelin and Ademe. The substitution process has beeneventually implemented by LME in cooperation with Aliapur over theyears 2002-2003. Industeel Belgium got started on substitution in2004. To day, both steel plants have achieved stable operation, witha regular load of 8 to 12 kg used tyres per ton of steel, thus allowingsignificant and sustainable savings on anthracite.

This article presents and discusses some modern techniques for high resolution orientation measurements in electron microscopy, including electron backscatter diffraction (EBSD) in the scanning electron microscope and spot and Kikuchi diffraction as well as dark field conical scanning in the transmission electron microscope. The techniques are compared with respect to their applicability to studies of nucleation processes during recrystallization of highly deformed metals. These investigations make high demands on orientation measurements, as high spatial and angular resolution and insensitivity to lattice defects are required.

les différentes méthodes qui utilisent l’essai d’indentation pour estimer la ténacité sont revues et commentées. Pour les matériaux fragiles, les formules sont principalement basées sur la mesure des fissures formées par l’indenteur ou, si l’essai est instrumenté, sur les décrochements (pop-in) observés sur la courbe charge-déplacement. D’autres méthodes moins connues peuvent utiliser la mesure de l’ouverture en fond de fissure, une équivalence entre la longueur de fissure formée et l’accroissement de pénétration de l’indenteur ou le clivage provoqué par une indentation proche du bord du matériau étudié. Pour les matériaux ductiles aucune fissure n’est visible à la surface, même pour les fortes charges appliquées. Dans ce cas la ténacité est reliée par la mécanique continue du dommage à un dommage critique mis en évidence par la diminution du module d’élasticité avec l’augmentation de la profondeur d’indentation. Toutes ces méthodes permettent de calculer la ténacité avec une incertitude pouvant aller au maximum à 50 %.

A physically based model to predict the strengthening kinetics induced by copper precipitation in the system Fe-Cu has been developed. The effects of aging time, temperature and composition are integrated in the model. The results of the calculations are in good agreement with the experimental observations.

An investigation was carried out to quantify and characterize the corrosion behavior ofAZ61A magnesium alloy joints. Extruded 6-mm-thick Mg alloy plates of AZ61A grade werebutt-welded using a solid-state, environmentally cleaner welding process, the frictionstir welding process. The weld specimens underwent immersion, salt spray, pitting andgalvanic corrosion tests in order to quantify and characterize the corrosion rates of thewelds with the influence of different pH values, chloride ion concentrations and thecorrosion time. The corrosion rates, microstructure, scanning electron microscopy andX-ray diffraction analysis concluded the optimum parameters for the usage of the magnesiumalloy welds for the best service applications.

Improvements of hot-dip galvanized products in metallurgy, coating quality and surface characteristics have led to coated products usable for automotive outer panels. With adaptation of processing parameters, if necessary, galvanized products give excellent results in forming, assembling and painting, as well as for functional properties (paint appearance and adhesion, corrosion resistance). This is particularly the case for ExtragalR, which is a pure zinc hot-dip galvanized product (GI).

To reduce roll wear and chatter vibrations in its hot strip mill, Eko Stahl carried out roll gap lubrication trials. The trial equipment, the lubricant and the trials themselves are described. Rolling force and consequently electric energy consumption were reduced by 8 to 34 % . The automation system reacted without difficulties to sudden rolling force changes. Three types of torque changes due to roll gap lubrication have been observed. Chatter vibrations have been suppressed efficiently during lubrication. Roll wear decreased. Strip thickness and profile tolerances were affected positively, other quality parameters did not change significantly.

Anthracite coal as fuel for iron ore sintering is compared withcoke breeze. Anthracite is lower in porosity, higher in density, andslower in combustion rate. With higher proportion of anthracite infuel, permeability of sinter bed tends to decrease resulting in lowersinter productivity. Higher fuel rate with more replacement of cokebreeze by anthracite is ascribed to the lower density of heat sourceparticles and to the lower heat value and more volatile matters ofanthracite. A smaller particle size for anthracite is recommended.Some subsidiary heat sources such as magnetite ore and mill scalecould be helpful for more uniform sintering.

Standard EAF operate with a large amount or air ingress (on theorder of 30 000 Nm3 for 150 t of steel). This air is at ambient temperaturethus, the nitrogen content and the non-reactive oxygen areonly heated through the furnace and exit with the fumes at high temperature(1000°C). This brings about significant thermal losses.Reference and airtight trials were carried out with the 6-t EAF ofArcelor Research for assessing the gains related to airtight furnaceoperation.

ULCORED is the concept suggested by SP 12 to meet thedemand of reduced CO2 emission using iron ore and gasbased direct reduction for steelmaking. The concept includesthe use of 100% oxygen, POX (partial oxidation) insteadof reformers, shifter for production of CO2 free reduction/excess gas and the reducing agent being either natural gas or syngas from coal/biomass.

The chemisorption of cold rolling oil additives on steel and aluminium surfaces is studied with a mass spectrometry technique, ToF-SIMS. Preliminary experiments underline adsorption competition, and thermal threshold for desorption or decomposition. This results fit well with experimental cold rolling results.

Use of stainless steel rebar for concrete reinforcement is increasingworldwide. The enhanced properties of stainless steel prove to be aviable solution when life cycle costs of the structures are taken intoaccount. Austenitic and duplex stainless steels are used as rebarbecause they present an excellent combination of corrosion resistancein concrete, high strength and good ductility.
The resistance to pitting corrosion of various stainless steels hasbeen evaluated by electrochemical tests. Thus, it is possible toselect the appropriate grade according to the environment the concretestructure is submitted to during its life. A classification of theselected austenitic and duplex grades is introduced.

Ultra-high strength steels with a tensile strength of 1,000 MPa to 1,200 MPa have been used for bumper and door beam since 15 years in Japan. Recently, it has been tried to apply these steels to reinforcements such as B-pillars inner and so on. The application of these types of steel tends to spread. Their formability, weldability and fatigue properties are described. Formability of ultra-high strength steel is different from that of mild steel, and it is governed by local elongation or stretch flangeability that can be evaluated by bendability. Local elongation or stretch flangeability has a negative correlation with total elongation. When strength exceeds 1,000 MPa, delayed fracture tends to occur. However, when measures to avoid delayed fracture are taken, there are no application examples of ultra-high strength steel sheet with 1,500 MPa tensile strength restricted by the danger of delayed fracture.

An integrated model developed by ArcelorMittal andNSC to predict the microstructural evolution of austenite inconventional and microalloyed HSLA steels during multi-passhot rolling is described. The prediction of austenite grain size,recrystallized fraction, residual strain and precipitation stateare given. Applications of this model during mono-deformationtests and during multi-pass rolling are presented.

Critical parameters that affect both the ferrite grain size and the precipitation kinetics during hot rolling Nb-bearing steel were studied.Accelerated cooling was applied after the last pass of finishing rolling.In all cases the Nb(C,N) precipitation was strongly retarded, increasingthe precipitation hardening by the formation of fine precipitates.Moreover a non-negligible amount of Nb remained in solution. Nb(C,N)precipitation occurred during annealing cold rolled steel, causingsecondary hardening.

Strip casting technology has many advantages, both technical and economical. In the Eurostrip project, this technology is applied to stainless steel at Krefeld (KTN) and to carbon steel at Terni (AST). The latest achievements of this technology are presented in this paper. Positive results are reported with respect to casting width, in-line hot rolling, in combination with in-line inductive heating. The technology is ready for industrial application.

An expert system model for a fume extraction system has been developed and installed at an electric arc furnace steelplant. Expert rules advise plant engineers of plant abnormalities that could result in fugitive emissions to atmosphere and/or result in excessive energy consumption. Neural network algorithms are incorporated into the model to mimic instrumentation and to analyse general trends. Since the installation of a prototype, significant financial savings have been made.

The Direct Reduction process can be carried out usingsyngas from biomass. Mathematical models of theintegrated process gasification plus direct reductionhave been used to evaluate flow rate, temperature andcomposition of the gas in the various steps of the wholeprocess. Fluidised bed gasification and operation withtechnological oxygen at high pressures is the proposedsolution to produce syngas. Best candidates for suchapplication are biomass from forest and wood industryand agricultural residues. Both of such type of biomassare present and distributed in many European areasin such amount to make industrially possible their use,taking into account the logistic requirements. A costbetween 30-60 Euros/t DRI is roughly estimated.
The characteristics of the syngas implies the adoptionof purification steps, before the use of the syngas inthe shaft furnace, using technologies permitting hot gascleaning, to save energy efficiency of the process.

The hot tearing of aluminium-copper alloys is a serious defect for the foundrymen. The grain refinement of these alloys allows to decrease their hot tearing susceptibility. The aim of this work is to better understand the hot tearing mechanism and the grain refinement action. So, hot tearing tests and tensile tests in the mushy state have been performed. Moreover, a hot tearing model, based on the nucleation and growth of a cavity in a liquid film and taking into account the mushy zone rheology, has been developed.