Today, the numerical simulation of fluid dynamic phenomena(CFD) in steelmaking applications is state of the art. Thelatest simulation results for the BOF and AOD as well asthe thin strip casting process are described. The basicinfluence of the process parameters, e.g. blowing andstirring rate, vessel dimension, location of top lance, numberand arrangement of porous plugs, on the converter meltflow and mixing time is simulated. In the case of thin stripcasting, the free melt flow on the moving belt is influencedby an induced electromagnetic field. The respective MHD(magneto-hydrodynamic) is presented.

The development of new highly sophisticated steelgrades with extreme demands on cleanness requiresaccurate refining. The paper gives an overview on thestate-of-the-art in secondary metallurgy and describesthe trends in secondary metallurgy research in Germany.

Understanding thermal transfer mechanisms in BOF converter is akey for higher energy efficiency, involving higher production capacityand lower CO2 emissions through low hot metal ratio capability.The developed model achieves a coupled description of the majorphenomena: refining reactions, mass transfers between phases, scrapmelting, post-combustion, slag formation. The calculated exhaustfumes enthalpy is fitting well the measured thermal balance trials withindustrial converter when implementing a detailed description of thepost-combustion. This model, compatible with real-time use, is also avaluable tool for further improvement in dynamic control of the process.

Environmental emissions constraints have led manufacturersto improve their low NOx recuperative burners. The developmentby Tenova of the FlexyTech® Flameless burners withlow NOx emissions, even below the present “Best AvailableTechnology” limit of 40 ppm at 3%O2 with furnace temperature1250°C, air preheat 450°C, is described. The results achievedduring the R&D programme have been also improved inthe industrial installations. Some details and performances ofthe recent furnaces equipped with such burners are provided.

The major objective of this research is to develop a 3-D FEM simulationtechnique in order to analyze the deformation behavior of surfacedefects on hot rolling. The developed technique will be applied toquantify the relationship between rolling condition and the processparameters, and the rolling pattern will be tested to verify and validatethe simulation technique. This technique will allow us to quantify theshrinkage of slab width at the head and tail, width spread after thehorizontal rolling, dog-bone shape, position change of the slab corneras the slab is being rolled, strain distributions. And the shape changeof surface defects in hot rolling was investigated using the 3-D rollingsimulation technique. The proposed prediction method of surfacedefect can be utilized to make defect free products in rolling.

Transient ladle reactions in IF steel melts are simulatedexperimentally. It is found that when Al2O3 is thermodynamicallystable, Ti has the effect of modifying the inclusions as a resultof local super-saturation. When Al2TiO5 is stable, the inclusionmorphology appeared to change into smooth, non-facettedshapes. When Ti oxide is stable, the possibility of generatingsecondary inclusions during solidification was investigated.

Industrial trials were carried out at the ArcelorMittal Isbergues slab continuous caster with the HJN (Hollow Jet Nozzle) previously developed at CRM at the pilot stage. This nozzle allows the addition of fine metallic powders in molten steel right before its solidification. These tests showed the possibility to implement the nozzle in an industrial stainless steel slab caster. It was observed a full melting of the injected elements (Fe and Fe-Ti), a homogeneous distribution of titanium element in slabs and a drastic improvement of the addition yield of titanium.

The kinetic study of the nitrogen dissolution was investigated.An isotope exchange technique is employed as a method formeasuring the rate of nitrogen dissolution into the molten steeland the effects of O, S, C, Mn, and B addition on surfacereaction have been considered at 1873 K.

UST rejection ratio of heavy plates was relatively high sincethe 300 mm thickness slab caster has been operated atPohang Works. An internal quality prediction system for slabwas developed that can evaluate the center segregationlevel of slabs within 5 minutes after cutting. The rejectionratio of heavy plate thicker than 70 mm could be reducedeffectively from 5% down to below 0.5% by applying thistechnology.

In most cases, hot metal dephosphorization slag is saturated withdicalcium-silicate that forms complete solid solution with tricalciumphosphate;the partition ratio of phosphorous between C2S andliquid slag is large. In order to utilize the effect of C2S phase for theimprovement of reaction efficiency, the optimum route of the slagcomposition change during dephosphorization should be clarified.The results of the fundamental experiments about the phosphorouspartition between C2S and liquid slag from the viewpoints of equilibriumand kinetics are reported.

Some highlights from the Jernkontoret Research with focus onthe modeling work of the last decade are presented. First theconcept of a fundamental mathematical model is discussed.Thereafter, a short review of growth and separation modelsbased on fundamental modeling of ladles is presented. Then,recent modeling efforts within Jernkontoret's Research arehighlighted.

Work based on both water model experiments and numericalinvestigations is presented. Basic flow pattern in a continuousslab casting mould adopting a BSP type nozzle is studied bynumerical simulation performed by the in-house code ofVisual Cast II, hiring the k-ε model, with results validatedby water model experiments. The structure of turbulence inthe mould is further studied by LES. The preliminary resultsreveal a certain match on transient flow patterns with thewater model experiments.

Principle and technological design of electroslag continuouscasting (ESCC), including bifilar mode, T-shaped mould andmetal level detecting system are detailed. Remelting is carriedout for a Cr18Ni9Ti stainless steel with ESCC. The surfacefinish, chemical composition, macro and microstructures, andinclusions of remelted billets are characterized. ESCC reducescost and increases productivity in comparison to the traditionalESR, while achieves comparably excellent products.

SIEMENS-VAI started the development for full automatic operationof all activities on the cast floor of continuous casting machines.A full size test robot was installed in a laboratory with on boardposition detection and all necessary tools. Specific solutions forallowing full automatic operation were engineered, manufacturedand tested. The first robot will go in operation in December 2007.

The end blow manganese behavior in BOF process wasassessed through analysis of an industrial data base.
The available literature suggests that the main operationalfactors to influence the end blow manganese behavior inBOF are: manganese input, slag volume, oxidation level andtemperature. The large extension of the industrial data basehas made possible to separate the influence for each factor.Then correlations between end blow manganese and thesefactors have been obtained.

The main purpose of ArcelorMittal Tubarao skin pass is to improvethe flatness in thin gauges hot rolled strips. Since the start-up in2002 several actions have been implemented and a consistentevolution of quality and process control has been reached:
The philosophy of production scheduling along the rolls campaignto minimize the effect of roll wear;
The definition of optimum target elongations to keep as constantas possible the roll forces and avoid roll bending changes;
The automation of bending forces control according tocharacteristics of the strip and the rolls.

Optimization of deoxidizer sequencing, such as Al and Ti, isan important topic which can provide improvement in termsof inclusion composition and process stability. Nevertheless,modeling inclusion nucleation and growth in a ladle is still achallenge, since different complex mechanisms are involved.The paper describes key steps which involve an importantmodeling investigation. The first step deals with deoxidizer meltingin a turbulent steel bath. The second is devoted to nucleationand growth of inclusions: thermodynamics criteria for inclusionprecipitation and turbulent agglomeration of clusters should besimultaneously considered.

Titanium-stabilized ultra-low carbon steels are often used in surfacequalitycritical applications and also susceptible to cloggingproblems in the casting process. The Automated Steel CleanlinessAnalysis Tool (ASCATTM), based on computer-controlled scanningelectron microscopy, was used to quantify the content andcompositions of inclusions present in the steel. The effects of alloyaddition timing at the RH degasser and of tundish slag compositionon cleanliness in these grades are discussed.

Raw materials like metals and minerals contribute by 40% tothe production costs of the industry, whereas the costs forenergy are about 1.6%. Although these figures are for thetotal industrial production, the figures show that it can beexpected that there is a great potential for cost savings in thesteel production, too.

A broad range of steel industry liquid effluents have beencollected from Corus site discharges for characterisation of theirchemical composition, their toxicity to the aquatic environmentand their oestrogenicity. This work was done as part of aEuropean funded research project, in order to investigate thepotential impacts of the Water Framework Directive on steelindustry processes.