The different models of sintering are reviewed, with a special attention to the developments in the last fifteen years. The models are classified between microscopic models, which describe the evolution of the material with a cell containing one or a few particles, models at the scale of the particle packing, and macroscopic models, which describe the evolution at a scale which is large compared to the particle size. Perspectives for the future are briefly discussed.

GI coatings are covered by a very thin aluminum layerthat precipitates after wiping. Anisotropic growing of zinccrystals during solidification induces a strong basal texturein GI coatings. Skin-pass induced changes in GI coatingsurface chemistry, crystallography and reactivity have beenassessed. Local coating analyses have been performed (XPS,TOF-SIMS) in order to describe local effects of roughnessindentation during skin-pass on coating characteristics. A laboratory bi-crushing device supported by XRD and EBSDhas been used to analyze the aluminum oxide behaviourduring deformation and ageing. Reactivity of such surfaceshas been tested using fatty acids.

Emission limits of the sinter waste gas have been continually andstrictly tightened in the EU for the last years. To cope with these environmentalchallenges, a survey about the sinter plant flue gas cleaningtechnologies was carried out within the VDEh sub-committee“Burden preparation”. This paper summarizes the main results of thissurvey and describes briefly principles of different processes andtechnologies including some of the latest development in the field ofsinter waste gas cleaning.

The paper reports the results of studies on the validation of a numerical model of theflow of liquid steel through the tundish used for continuous casting of steel. Thefacility under investigation is a single-nozzle tundish designed for casting concastslabs. For the description of the turbulence of steel flow through the tundish, thek-ε, RNG k-ε and Realizable k-ε turbulence model wereadopted. Computer simulations of liquid steel flow were performed using the commercialprogram Ansys-Fluent®.For the validation of the numerical model and verification of the hydrodynamic conditionsoccurring in the examined tundish furniture variants, obtained from the computersimulations, a physical model of the tundish was employed. During laboratory testssimulating the process of steel flowing through the tundish, E and F-type RTD (ResidenceTime Distribution) curves were recorded, which were then juxtaposed with results obtainedfrom computer simulations. In order to obtain a complete hydrodynamic picture in thetundish furniture variants tested, the computer simulations were performed for bothisothermal and non-isothermal conditions.

Oil layer and surface roughness of steel strip are measured on-linewith equipment that has been adapted to withstand the severe environmentof a cold rolling mill. The system ensures the effective lubricationof the strip and it displays roughness data all along the coil.This makes it possible to optimize the rolling process on-line and itaffords comprehensive information on the strip properties.

ArcelorMittal Monlevade is an integrated plant with sinter plant,blast furnace, BOF, ladle furnace, continuous caster, and rolling mill,with a capacity of 1.2 million tpy. During the last years, Monlevadehas been raising the ladle free open index through refractory qualityimprovement and standardization of operational parameters. The mainactions were changing of the geometry of ladle well block and nozzle,use of two-layer sand, and control of sand residence time before BOFtapping. Based on these facts, the ladle free open index has increasedfrom 98.5 to 99.8% from 2002 to 2006.

CRM has developed a dynamic model of the EAF. Combined with a complete acquisition of process parameters and of events occurring during a heat, the model continuously assesses the mass and thermal balances; it simulates the scrap movement inside the furnace during melting down as well as the foaming slag. It is in daily use at Carsid-Marcinelle since two years. Its second application is at the furnace of ProfilArbed at Esch-Belval. The model allows to determine the optimum time for the charging of the second scrap basket, to control the heating during the flat bath phase and to predict the end point of the melting. The model is also an efficient tool for the optimization of the electric furnace.

The influence of LF refining slag composition on desulfurization and inclusionmodification was investigated through industrial experiments and thermodynamic analysis.The results show that the sulfide capacity decreases with the decrease in(%CaO)/(%SiO2)and (%CaO)/(%Al2O3) of the slag. The theoretical sulfur distributions agreewell with the analysis results when the sulfide capacity is calculated by Zhang’s model,but the theoretical sulfur distributions are higher than the analysis results when thesulfide capacity is calculated by the KTH model. During the LF refining process,inclusions are transformed from Al2O3 inclusions into CaO-MgO-Al2O3 system inclusions. Higher slagbasicity results in higher CaO and MgO and lower Al2O3 content inclusions in moltensteel at the end of the LF process.

Study of the acid bake-leach process has shown potential advantages for the treatment ofenargite (Cu3AsS4) concentrates. Among the most important advantages of theprocess is the transformation of enargite to water-soluble copper sulfate and highlysoluble arsenic trioxide (arsenolite). Because arsenic is retained in the condensed phaseduring the baking, the vapor pressure of arsenic trioxide should be estimated at typicalbaking temperatures (e.g. 473 K). To that end, the vapor pressure of As4O6 (g) was estimated under thebaking conditions based on published thermodynamic values. The vapor pressure ofarsenolite at 473 K was found to be approximately 9.03 × 10-4 atm. Based on thelinear regression analysis of the published vapor pressure values for arsenolite in thetemperature range 366−579 K,the equation for the best fit line was found to be as follows, with a correlationcoefficient of 0.9973:

logPArsenolite(atm) = (-5780.7)/(T (K))+9.16.

Available information on arsenic trioxide does not allow a definite conclusion regardingthe arsenolite/claudetite transformation temperature and their exact melting points.However, the transition temperature has been reported to be in the wide range of240−506 K in differentreferences. Furthermore, the thermodynamic information concerning arsenolite/claudetite issparse and at times not consistent. An effort has been made in this paper to compile themost reliable thermodynamic information for arsenic trioxide (arsenolite and claudetite).

Formation of deposits inside the submerged entry nozzles used in continuous casting ofespecially low-silicon Al-killed mild steels may often cause nozzle clogging and castingdisorder. Technological experience has shown that the application of Ca-treatment beforecasting usually eliminates this phenomenon. In order to understand deposit formation andthe way it can be avoided, we have carried out detailed mineralogical analyses of thedeposits formed on the inner and outer surfaces of the nozzles by different techniques.Results obtained from deposits formed during the casting of only Al-killed andsubsequently Ca-treated steels show that the results obtained from deposits formed duringthe casting of only Al-killed and subsequently Ca-treated steels show that the aluminainclusions carried to the wall of the nozzle form the matrix of the dangerous deposits.Application of Ca-treatment resulted in mostly liquid aluminates compounds and almostnegligible deposit formation. The outer surface of the nozzles however showed similardeposit formation because of possible reoxidation of dissolved aluminium.

A model of lubricated cold strip rolling is extended to the thin foil case. The model considers the evolution of asperity geometry and lubricant pressure through the bite. Friction between the roll and the asperities on the strip is modelled using the Coulomb and Tresca friction factor approaches. The shear stress in the Coulomb friction model is limited to the shear yield stress of the strip. A novel modification to these standard friction laws is used to mimic slipping friction in the reduction regions and sticking friction in a central neutral zone. The variation of rolling load, lubricant film thickness and asperity contact area with rolling speed is examined, for conditions typical of rolling aluminium foil from a thickness of 50 to 25 μm.

Recent investigations have shown that an iron oxidation / reduction process can improve the quality of the coated steels by decreasing the amount of external selective oxidation. This economical process can be made during heating by modifying the air/gas ratio of the direct fire furnace or in the rapid cooling section by air injection. A sensor allows measuring continuously the iron oxide thickness of the oxidized strip.

The influence of variable Manganese content (2.4−4.6 wt%), while keeping constant Silicon(1.5 wt%) and Chromium (0.3 wt%) levels, and variable oxidation potential of the annealingatmosphere on hot dip galvanizability was investigated. Surface oxides prior to hot dipgalvanizing were analyzed and coating quality assessed. The increasing oxidation potentialof the annealing atmosphere led to a transition from external to internal selectiveoxidation of Mn, Si and Cr; their enrichment at the surface could be reduced and themetallic iron at the surface was increased. Hot dip galvanizability could thus be obtainedup to 2.9%Mn. With increasing Mn content, the surface was covered by a rising amount ofMn-oxides. By exceeding a critical amount of Manganese, reactivity in the Zinc bath wasdeteriorated. This amount was found to be between 2.9 and 3.8 wt% for Si content of 1.5wt%.

Materials have been central to the development of civilization, as they constitute thebackbone of our society and of our technology, as all things are made of materials and allof them are made by tools mainly made of metals, and especially iron and steel. In modernlanguage, they have become central to the sustainability of our society. Speaking about ormeasuring this relationship, however, is complex. Life Cycle Thinking is an important toolfor doing this, but it was not developed with materials in mind and it focuses only onthat small part of sustainability related to environmental impacts. Economic and societalissues require other methodologies and all these complementary visions have to beaggregated in order to report properly on sustainability matters. To advance towards sucha new tool, called the New Metrics, an Initiative called SOVAMAT was launched 10 years agoand a Community has shaped up, binging together academics from a broad array of hard andsoft disciplines, materials producers from metals to plastics, glass, paper/cardboard,concrete, carbons, wood, etc., and materials users, including meta-users who work onecodesign, for example. The agenda of the Initiative is moving forward, improving existingmethodology, extending it and aggregating various tools towards the final target of theNew Metrics. The SOVAMAT Community meets regularly in annual seminars called Society andMaterials or SAM. This paper explains the questions addressed by the Initiative and someof its early successes.

Shredded old tires can replace coke in the electric arc furnace, if some simple rules are followed to charge and use them. Experimental runs were carried out in two French steelshops for longer and longer periods of time and the substitution rate of carbon by tires was determined. Environmental measurements were also made in order to check emissions in the smokestack and inside the shop.

Because of the importance of lightweight constructions, nowadays other materials are moreand more substituting components which had previously been made of metals. The usage ofshort fiber-reinforced plastics instead of metals seems self-evident in many cases becauseof their high specific strength and the favorable manufacturing processes. For fatiguelife prediction a simulation process was established, which takes into account the fiberorientation and distribution as a result of an injection molding simulation. Hypothesesfor fatigue life prediction of orthotropic materials have been derived from a lot of testson specimens, implemented in the standard fatigue software tool FEMFAT and verified so farwith component tests.

A new technique for production of bulk ultrafine grained metallicmaterials is proposed. The principle and possible design of the newtechnique, referred to as 'cone-cone method' (CCM) are outlined. Itis suggested that CCM can be used to produce sheet or strip materialswith uniform microstructure. This is substantiated by the resultsof numerical simulations that demonstrate the viability of the process.

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.

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 processes for direct and smelting-reduction of iron ores have, compared to the blast furnace, the advantage of being independent from coke. They will gain importance for mini mills based on the EAF steelmaking route. DRI capacity and production have steadily increased worldwide over the past three decades. DRI production in 2002 was 45 Mt and utilization of installed capacities reached 97%. A further increase in capacity and production is expected. The only smelting-reduction process under industrial application is the Corex process. The four operated plants in the world have in 2002 produced 2.66 Mt hot metal.