Increasing demands on cold strip quality place a growing requirement on good flatness. Traditional flatness measurement systems are contact based systems, which can cause scratching of the strip surface, and require extensive maintenance work. The SI-FLAT method developed by Siemens uses a contactless measuring principle. It minimizes the risk of scratches and reduces operating and maintenance costs. The system is less sensitive to tension variations and mechanical misalignments, and provides best resolution at the strip edges because of narrow sensor stacking and integrated strip edge detection. SI-FLAT is proven for steel, stainless steel, non-ferrous material and aluminium.

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.

The role of the tundish in the continuous casting process has evolved from that of abuffer between the ladle and mold to being a grade separator, an inclusion removal deviceand a metallurgical reactor. For both grade separation and inclusion removal, the flowpatterns inside the tundish play an important role. The separation of non-metallicinclusions at the interface between the steel and the slag in the tundish is to a greatextent controlled by interfacial phenomena in the steel-slag-inclusion system. Oneconstant in the world of high-purity, low-residual and clean steels is the continual driveto reduce and control the frequency of the inclusions. For example, there are high-purity,low-residual clean steels such as IF- steel sheets for automobiles which require theabsence of oxide inclusions with diameters larger than 100 micrometers. Great efforts havebeen made to optimize the flow and turbulence in the tundish through weirs, dams or othersystems. Furthermore, a new system, the porous annular well block for injecting argon, hasbeen developed to optimize the bubble size and distribution and hence to achieve a highefficiency in trapping inclusions and in decreasing the hydrogen content in steel.Consequently, the steel quality is further improved in the tundish. Tested with success ina seamless steel shop, the new system gives results in agreement with the water models.

p-methoxy benzylidene malonitrile (MN1) and p-hydroxy benzylidene malonitrile (MN2) were synthesized and tested as inhibitors for the corrosion of mild steel in molar HCl. We have found that both of them inhibit the corrosion. The maximum inhibition efficiency reached 100% for MN1 at 10-4 M and for MN2 at 10-3 M. Current-voltage curves indicated that malonitriles act as mixed type inhibitors. Their adsorption on the steel surface obeys to the Langmuir isotherm model. The effect of temperature on the corrosion behaviour of steel indicated that the inhibition efficiency of the two inhibitors decreases slightly with the rise of temperature in the range 298-338 K. The apparent activation energies for steel dissolution are greater than in the absence of inhibitors, which is consistent with a chimisorption mechanism.

The effect of blast furnace productivity on the erosion of the hearth wall and the campaign life was examined. First, the molten iron flow in the hearth was studied by a model experiment and an iron flow estimation model calculation. Next, the temperature distribution in the hearth wall was calculated by a heat transfer model, and the erosion of the wall and formation of the solidified layer were estimated. The study led to the erosion pattern during the blast furnace campaign life, which was verified by the actual furnace erosion pattern.

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.

The recent unexpected discovery of a degassing flow from the metal to the hydrogen charging environment, which operates simultaneously with the crude charging flow, has given new interest to the former concepts of internal and external hydrogen, coupled with a new type of cathode protonic reaction. This affects considerably the way permeation experiments are conducted and their results interpreted. This paper proposes a new approach allowing, among other things, to explain what appeared formerly as anomalies, especially in the area of thin membranes.

The future evolution of energy supply technologies strongly depends on (and affects) theeconomic and environmental systems, due to the high dependency of this sector on theavailability and cost of fossil fuels, especially on the small regional scale. This paperaims at presenting the modeling system and preliminary results of a research projectconducted on the scale of Luxembourg to assess the environmental impact of future energyscenarios for the country, integrating outputs from partial and computable generalequilibrium models within hybrid Life Cycle Assessment (LCA) frameworks. The generalequilibrium model for Luxembourg, LUXGEM, is used to evaluate the economic impacts ofpolicy decisions and other economic shocks over the time horizon 2006−2030. A techno-economic (partialequilibrium) model for Luxembourg, ETEM, is used instead to compute operation levels ofvarious technologies to meet the demand for energy services at the least cost along thesame timeline. The future energy demand and supply are made consistent by coupling ETEMwith LUXGEM so as to have the same macro-economic variables and energy shares driving bothmodels. The coupling results are then implemented within a set of Environmentally-ExtendedInput-Output (EE-IO) models in historical time series to test the feasibility of theintegrated framework and then to assess the environmental impacts of the country.Accordingly, a disaggregated energy sector was built with the different ETEM technologiesin the EE-IO to allow hybridization with Life Cycle Inventory (LCI) and enrich the processdetail. The results show that the environmental impact slightly decreased overall from2006 to 2009. Most of the impacts come from some imported commodities (natural gas, usedto produce electricity, and metalliferous ores and metal scrap). The main energyproduction technology is the combined-cycle gas turbine plant “Twinerg”, representingalmost 80% of the domestic electricity production in Luxembourg. In the hybrid EE-IOmodel, this technology contributes to around 7% of the total impact of the country’s netconsumption. The causes of divergence between ETEM and LUXGEM are also thoroughlyinvestigated to outline possible strategies of modeling improvements for future assessmentof environmental impacts using EE-IO. Further analyses focus first on the completion ofthe models’ coupling and its application to the defined scenarios. Once the coupling isconsistently accomplished, LUXGEM can compute the IO flows from 2010 to 2030, while theLCI processes in the hybrid system are harmonized with ETEM to represent the futuredomestic and imported energy technologies.

In the development of the electrolysis technique for iron,the cell-design step is crucial to ensure that the resultsobtained on smaller scale experiments are scaled-up toindustrial size. Design criteria, based on the theorem ofequipartitioned irreversibility, are proposed for the alkalineelectrowinning process. One of the specific features ofthe process is the treatment of a multiphase electrolyte, agenuine breakthrough for electroextraction processes. Eachof the unit-operations necessary to obtain the separation ofthe iron and oxygen from iron oxide are depicted togetherwith the corresponding physical limitations and availabletechnologies. Optimal solutions to obtain uniform andsteady variation of each of the involved phenomena canbe readily deduced from this approach and a cell-design isproposed.

The beneficial effect of B on the hot ductility of 20CrMnTi steel with 0.05% Sn wasinvestigated. The results show that there is a trough in the hot ductility-temperaturecurve. With the increase in the B content, the trough shifts to a lower temperature andbecomes shallow, and the hot brittle range becomes narrow. In addition, B greatlyenhancing the hot ductility was due mainly to its suppressing the Sn segregation,retarding the austenite/ferrite deformation, accelerating the onset of dynamicrecrystallization (DRX) and promoting the intragranular nucleation of ferrite. Moreover,in the present case, adding 92 ppm B can nucleation of ferrite. Moreover, in the presentcase, adding 92 ppm B can obtain the best effect in improving the hot ductility of20CrMnTi steel with 0.05% Sn.

The determination of residual stresses and the analysis of phases in zirconia layers obtained after oxidation of Zy-4 and Zr-1%Nb-O sheets have been performed using X-ray diffraction with synchrotron radiation at 20 and 400°C. These experimental analyses have been compared with calculations using a micromechanical approach (thermoelastic behaviour) and also with a macroscopic approximation of the thermal stress due to cooling. The main result is the small influence of cooling on the residual stresses developing in the zirconia layer, especially for Zr-1%Nb-O.

Belgo-Mineira, Arcelor Group, has at Monlevade Works one sinterplant with 120 m2 of strand area and its own iron ore mine (Andrade mine). Aiming to increase sinter production combined with the use of 100% of its own iron ore, the Hybrid Pelletized Sinter (HPS) process, developed by JFE (former NKK), was chosen among other alternatives. The HPS process started up at Monlevade Works in December 2002 and since January 2003 100% of Andrade iron ore has been used at the sinterplant. The contractual sinterplant productivity target (42 t/m2.24h) has been achieved.

Flameless oxyfuel combustion used in industrial furnaces gives a uniformtemperature and heat flux distribution along with high availableheat. NOx emissions can be maintained at extremely low levels, meetingthe most demanding environmental regulations. Since 2003 theexperimental results from flameless oxyfuel technology have been provenin industrial installations such as reheating and annealing furnacesas well in ladle preheating stations.

The twin cathode technology by Danieli is the new generation of DC superpower EAF. This design concept allows the utilization of reduced diameter standard electrodes and low density currents compared to single electrode DC or standard AC EAF of the same power. The operative results of this technology are shown at Hylsa Aceros Planos Mexico.

Surface corner cracks are sometimes observed on slabs of highstrength low alloyed steel grades, requiring expensive scarfing.To avoid surface crack formation, we can act on the steel intrinsicductility loss through the limitation of S and N contents: S < 30ppm and N < 40 ppm are well adapted thresholds. A Ti/Nratio higher than 3.6 and a limitation of Al*N product leadto a significant improvement of the quality results. In addition,the continuous casting process must be optimized. It aims atlimiting the thermomechanical strains faced by the slab surfaceduring solidification and cooling, particularly when the slabcorner temperature is in the range of the ductility trough. Themain process actuators are the mould powder, the secondarycooling curves and the limitation of the misalignments inthe top part of the caster, especially the transitions betweenthe mould foot-rolls, the vertical and the bending segments.

Multi-thickness blanks (MTB) enable the weight and the design of a part to be optimized thanks to an appropriate distribution of thicknesses and/or mechanical properties. This is usually obtained by adding a reinforcement piece onto the main part, both having been previously cut and stamped separately. With MTB, pre-cut blanks are assembled before being stamped together. This allows, in particular, the stamping and assembling operations to be decreased, with a cost reduction thrown in. MTB's gather tailored blanks, already well known and broadly used, and patchwork blanks which are nowadays mainly at a development stage and give rise to an increasing interest due to their potentialities.

For every mill the ideal roll can be considered as one that can be used in a mill stand indefinitely. Unfortunately for the roll user, such ideal rolls do not exist. One major reason for work roll changes (planned or unplanned) is “wear”. In the context of cold rolling and temper rolling, “wear” primarily refers to loss of roughness and/or surface texture. Another limitation to roll performance is the fact that mill incidents – minor as well as major incidents – inflict damage on the work rolls, requiring redressing in the roll shop. If a major defect is present in a forged roll, e.g. due to a mill incident, catastrophic roll failure may occur in a violent, explosive manner. Improvement of the value-in-use of a work roll implies a superior wear resistance, a superior damage resistance, and elimination of the safety risks associated with explosive roll failures. In order to deal with this in a concerted R&D approach, a consortium of two roll users in the steel industry, a leading roll manufacturer, a high-tech supplier of roll damage detection equipment, and specialised research institutes have joined forces. Cold rolling trials have been performed, using pilot mills as well as industrial mills, with both novel forged HSS work rolls and conventional forged 3–5%Cr steel work rolls. Separate trials have been designed to focus on either the aspect of roughness evolution or damage resistance. Complementary data from various laboratory tests and industrial mill and roll shop data have been collected. Models have been developed for damage evolution in a roll, and for roughness evolution of the roll surface. In addition, novel non-destructive detection systems and sensors have been designed and tested. This paper provides a concise overview of the results achieved.

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).

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.

This paper reports on some aspects of a ENI Group feasibility study of high pressure (> 100bar) - high strength pipelines designed for transportation of large quantities of naturalgas over long distances (> 2500 km). The experimental results obtained in collaborationwith Centro Sviluppo Materiali (CSM) and ILVA L.T. clearly showed the full reliability ofmodern high strength linepipe materials of X70-X80 grade, with respect to fracturebehaviour, even at low temperature, in very high pressure regimes.