Phenomena that occur at the meniscus in the CC mould have a major effect on product quality. The mechanism of slag rim behaviour andflux infiltration are reported based on the results of industrial characterization and of fluid dynamics modelling of the effect of oscillation andshell velocity.
Lubrication stability is not established as the slag film happens to be broken down and renewed several times during casting. A mechanismof slag infiltration is put forward and the main factors for oscillation marks formation are pointed out.

Strip width necking may be quite significant on cold rolling mills. Tocompensate for this unpredicted phenomenon, hot strips are oftenordered with an over-width with resulting substantial over costs, fortrimming in particular. Based upon numerical simulation supportedby rolling trials, the main factors that effect strip width variation havebeen quantified: edge drop, transverse stress relaxation, thermalcontraction. Potential width actuators to be implemented on industrialcold rolling lines have been identified.

The investigation of dioxin formation mechanisms demonstrated that most part of PCDD/F formation occurs in the sinter mix during the sintering operation. This result has a direct impact on abatement strategies of PCDD/F: use ot inhibitors added in the sinter feed and study of the impact of raw materials. Trials carried out on the IRSID pilot pot and on the Charleroi sinter strand have shown that urea addition could be a promising method to reduce pollutant emissions at the sinter strand main stack: PCDD/Fs (about - 50%) and SO2.

In order to develop a new, efficient industrial process forproducing high quality iron and steel with significantly reducedcarbon dioxide emissions, we investigated the electrowinningof iron from an iron oxide ore in aqueous alkaline solutions.Hematite (Fe2O3) solid particles suspended in the concentratedaqueous sodium hydroxide (NaOH) solutions were transferredto the cathode (e.g., a rotating disk graphite electrode) andreduced to iron metal by applying a constant current; oxygenwas evolved on the anode (e.g., a nickel screen mesh). Currentefficiencies of above 90% with respect to iron depositionwere consistently obtained under the specific conditions in alaboratory cell, and the corresponding energy consumptionswere calculated to be around 3 kWh·kg-1 iron. The depositediron crystals were the oriented clusters of stacked six-fold twins ina tetrahedron-shape grew growing in a direction perpendicularto the cathode surface. Influences of rotation rates of the cathode,cathodic current densities, contents of the Fe2O3 particlesin electrolytes, and concentrations of NaOH solutions oncurrent efficiency and morphology of deposits were studied.

Two complementary techniques are mainly used for the detectionand characterisation of the inclusions populations present in thesteel bars in a large range of sizes: from 1 μm to 1 mm: the automaticscanning electron microscope associated with image analysisand the 80 MHz ultrasonic inspection. The emphasis has been puton the composition of the inclusions whose size is above the criticalsize (10 - 20 μm) for long life fatigue. The mechanism of formation ofthese harmful inclusions is determined through the process with thehelp of thermodynamics models. This approach makes it possible toimprove the process: avoiding slag entrapment upon casting of bearingsteels, adjusting closely the Ca addition to calcium treatedsteels.


Un modèle thermique a été développé afin d’identifier les sources de chaleur accompagnantles déformations micro-plastiques intervenant au cours d’un essai de fatigue cyclique.Dans la première minute de chaque palier, un modèle de barre infinie permet de différer laprise en compte des pertes conductives par les mors. Les sources sont identifiées au fildes paliers de chargement croissant, tout en évitant d’entrer dans le domaine deplasticité macroscopique.

In order to achieve comparatively constant BOF process data, a radar measurement equipment was installed at the two 185-t vessels at the Dillinger Hütte steelplant. The level of liquid steel in the converter is easily measured for every heat with a radar unit. With this installation, the distance between the tip of the oxygen blowing lance and the steel surface can be adjusted in accordance to process conditions. As a result, metallurgical and technological improvements were achieved, e.g. the Fe-content of the slag was reduced and the lime consumption could be lowered as well. A more uniform lining wear can be observed and the life of lance tips is increased.

A rolling force model of continuous cold rolling mill based on elastic and plastic mechanics was developed and successfully applied in the control system of a 1420 mm cold rolling mill in Baosteel. Considering simplicity and practicability of calculation, stress of elastic zone and plastic zone during the cold rolling process was calculated and analyzed by incorporated simple finite element method and recursive calculating method. Compared with the measured rolling force, the results of the rolling force model are beyond 96.5%. A method for optimizing rolling force by improving reduction, dimension, coefficient of friction, deformation and tension is put forward.

The part-bath heat transfer coefficient during a quenching operation is particularly important in order to simulate the workpiece hardening. The estimation of this coefficient requires specific developments in the field of instrumentation. This paper presents an experimental methodology which was developed within the laboratory. Experimental results are compared to numerical simulations using a heat transfer coefficient obtained from experimental estimation. This comparative approach allows to validate the experimental methodology and also to ensure that the tested pieces are representative.

EMF in a blast furnace can be used to predict liquid level variationsinto the hearth. After the strong influence of some process parametershas been minimized, the variation of the EMF at the end ofconsecutive castings can be used as a criterion of liquid level variations.Currently this criterion is integrated in a mathematical modelthat sends messages to an on-line advisory tool.

The DSR (Dynamic Shape Roll), a powerful flatness actuator developed by VAI Clecim, has been installed and commissioned on the No. 1 tandem cold rolling mill of Baoshan Iron and Steel in 1997 and more than 4 million tons have been rolled with this equipment. This long operation period allows us to quantify the first operational results in terms of performance, capacity and operation of this actuator on a wide range of products. This also allows us to confirm the potential gains induced by this innovative technology with regard to the market changes and requirements.

The background of the development of the BRP technology(Baosteel BOF Refining Process) is presented along with the experimentalconditions and results. The relations between dephosphorizationand basicity of slag, bottom blowing, temperature at endpoint are analyzed. The effects on dephosphorization of bottom blowing,total iron of slag and silicon content in hot metal are also considered.The performance results indicate that, in the de-P converterand the de-C converter respectively, the dephosphorization efficiencyis over 84% and 64% with phosphorus contents below 0.014%and 0.005%. Steels that are difficult to elaborate, such as tire cordedor X 65 pipeline steel with HIC-resistance benefit from the BRP technologyin Baosteel.

Insuring stable supply of wide-width quality slabs for HR/CR automotive and API applications was the main reason for revamping the Posco Gwangyang No. 1-3 machine that is, incidentally, the only large-width slab caster (up to 2,000 mm) in operation at Gwangyang Works. To meet that objective, both at the surface and internal quality points of view, several technical advances were included in the project such as: vertical-bending, multi mode electromagnetic stirring in the mould (MM EMS), hydraulic mould oscillation (DYNAFLEX), split and short-pitch strand guide rolls, soft reduction (ASTC) and dynamic secondary cooling control (DYNACS).

In the general frame of energy saving, environment protection and the concept of circulareconomy, the fundamental research on the sintering technology with super deep bed,achieving energy saving and emission reduction, was carried out. At first, thecharacteristics of the process and exhaust emission in the sintering with super deep bedwas mastered through the study of the influence of different bed depths on the sinteringprocess. Then, considering the bed permeability and the fuel combustion, their influenceon the sinter yield and quality, their potential for energy saving and emission reductionwas studied. The results show that the improvement of the bed permeability and of the fuelcombustibility respectively and simultaneously, leads to an improvement of the sinteringtechnical indices, to energy saving and emission reduction in the condition of super deepbed. At 1000 mm bed depth, and taking the appropriate countermeasure, it is possible todecrease the solid fuel consumption and the emission of CO2, SO2,NOx by 10.08%, 11.20%, 22.62% and 25.86% respectively; and at 700 mm bed depth, it ispossible to reduce the solid fuel consumption and the emission of CO2,SO2, NOx by 20.71%, 22.01%, 58.86% and 13.13% respectively. This researchprovides the theoretical and technical basis for the new technology of sintering withsuper deep bed, achieving energy saving and reduction of emission.

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.

Developments in electronic structure calculations and computer performances have made it possible to perform ab-initio calculations of structural properties of materials, like defect parameters in transition metals. The values of vacancy formation and migration enthalpies calculated in this context agree with experimental data within less than 10% . Reliable self-diffusion coefficients for the vacancy mechanism can be deduced. This approach sheds new light on the so-called self-diffusion anomaly in body centred cubic metals.

Kwangyang has been operating five large size blast furnaces and K-1 BF was relined in March 2002 after finishing 15 years of operation successfully. To secure enough cast pig iron as one of countermeasures to a low HMR at the steelmaking process during the relining period, four other blast furnaces came to increase their productivity in advance, before the start of the K-1 BF long stoppage. Particularly, during the ultra-high productivity operation period from March to June, K-3 BF marked a new POSCO productivity record and a new silicon record simultaneously on May in spite of unstable sinter consumption due to the width extension of No. 1 & No. 3 sintering strands and 13 years furnace life. It was 2.76 t/day$\cdot$m3/IV in productivity and 0.15% in silicon level in pig iron. These remarkable records were based on some advanced Kwangyang BF know-how and recent developments like higher facilities reliability, optimum allotment of hot blast and oxygen, high sophisticated burden distribution control and special screening equipment of raw materials.

Aluminium (Al) consumption growth exceeded those of all other major metals over the lastdecades. The main driver for this development is the broad range of applications for Aland Al-alloys. As the growth in consumption went along with an increase of anthropogenicstocks and flows of Al, information about material cycles became a crucial issue in termsof resource management. In this study a comprehensive material flow analysis (MFA) of theflows and stocks of Al in Austria for the year 2010 is conducted. The focus of thepresented Al balance is on data harmonization and plausibility checks, both based onextensive data and literature research. The stock of Al is derived from bottom-upcalculations indicating a total stock of about 260 kg Al per capita with an annual growthof 11 ± 3.1 kg/cap yr in 2010.Total old Al scrap generation is calculated to be 7 ± 1 kg/cap yr. For considering dataquality aspects of single input data an adopted method for uncertainty assessment has beenapplied to the different material flows. This allowed a consistent evaluation ofuncertainties within the material flow model. Due to the substantial uncertaintiesassociated with end-of-life Al flows and their significance for secondary Al production inAustria, a better data base is needed in order to evaluate and optimize national Al scraputilization in secondary production. Therefore, a dynamic MFA model will be built forAustrian Al flows and, in conjunction with the results from the static analyses, willprovide a reliable decision basis for future Al resource management.

The pickling line and cold rolling tandem mill at the Parrows Point Works of Bethlehem Steel Corporation are linked in a continuous processing complex. This complex has been automated by VOEST-ALPINE Industrieanlagenbau (VAI) through the implementation of a comprehensive package of innovative solutions. This project has contributed to improve significantly the quality parameters of the strips produced by the cold rolling plant (thickness, flatness, etc.) and to increase its yield.

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.