Irsid and DCPR from Nancy present an investigation on the generation and the abatement of organic molecules in the flue gas of an electric arc furnace. Investigated in detail are the environmental cleanliness of scrap, the mixed pyrolysis and combustion that generates these molecules, the solution to destroy them completely that a perfect post-combustion offers, as demonstrated in the laboratory and as extrapolated for industrial scale, and the condensation of dioxines in the flue gas collection system.

The coke making industry has seen substantial technological development over the last decade. Conventional coke ovens (slot type ovens) with raw gas recovery have reached dimensions of more than 8 m height and 90 m3 useful oven volume, boosting the capacity of a single battery to 1.3 Mt/y and the production of a single coke plant with one operating team to 2.6 Mt/y. At the same time, the emissions from batteries and gas treatment facilities have been reduced to the lowest amounts ever. A further increase in energy efficiency and environmental protection for conventional coke batteries is expected from the combustion of the hot raw gas with subsequent generation of electricity. The concept of a coke plant with direct combustion of the raw gas would omit the entire gas treatment plant and produce only coke and power. Aside from these achievements with conventional coke oven batteries, the non-recovery technology has also found acceptance. Coke plants of this type are in operation in the USA, Australia and India. One plant in the USA is a heat-recovery coke plant that produces power from the waste gas. Further improvements in plant efficiency and coke quality are achieved with stamping of the coal charge, which is now developed for non-recovery ovens, too.

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 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.

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.

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.

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.

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.

Many materials can only be recycled a limited number of times because of physicaldegradation (paper and board), chemical degradation (plastics), or impurities (severalmetals). Management of the quality of materials is a key to high long-term recycling ratesand, hence, to the sustainable future. This key includes several elements, such as:retaining the quality of materials in the production and use of products; retaining thequality of materials in the recycling processes; and using high-quality materials onlywhen it is required. Pinch analysis is a set of methods to optimize physical flows bytaking the quality into account. It was originally developed for minimizing the energydemand in process industries. It has been adapted for optimization also of water andsolvents flows. A Japanese research group applied part of the method on flows of steelwithin Japan and globally. We present a pilot study that illustrates how all the elementsof the basic pinch approach can be applied to global systems of material flows. Ourmaterial pinch analysis (MPA) distinguishes between three categories of steelapplications, each with its own requirements on the material quality: rolled steel,sections and re-bar. Copper in wiring etc. increases the copper content of steel recycledfrom machinery and eventually restricts the recyclability of the steel in a global systemwhere steel use does not increase. This is important because an MPA is mainly relevantwhen impurities or other quality aspects restrict the recycling rate. Our quantitativeresults should not be considered accurate reflections of the reality, because the pilotstudy is to a large extent based on assumptions and crude data. However, the model gives afirst indication that the maximum recycling rate of steel is approximately 80% in apotential future when steel use does not increase, unless technology is improved. A fullMPA with more thorough data collection would more accurately define the maximum long-termrecycling rate and the minimum quantity of ore-based material. In addition, a full MPAwould give information on for what applications ore-based material should be used, andwhat scrap flows should be discarded rather than recycled. Such information can beimportant for policy-making aiming at increased resource efficiency. If it is importantfor policy-making it is also likely to be important to industrial companies that can beaffected by policies.

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).

This paper describes a new approach for the functional characterization of the surface topography of metallic products. The aim is to determine in a quantitative and unbiased way the roughness parameter which describes best the property or the function of the material. To achieve this, a new numerical statistical treatment had to be defined and a specific software had to be designed and developed. With these tools, more than 100 roughness parameters can be calculated. The most pertinent one for the description of the relationship between brightness and roughness of cold rolled steel sheets is the fractal dimension.

LKAB's experimental blast furnace with a hearth diameter of 1.2 m and a working volume of 8.2 m3 produces approximatively 35 tons of hot metal/day and, not the least, valuable information. The furnace is used for the evaluation of burden materials and combinations as well as of modified or new blast furnace operational concepts and equipments. Nine campaigns ranging from 6 to 11 weeks have been performed since the start up in 1997.

Several ferritic stabilized and austenitic stainless steels were investigated under cyclic high temperature corrosion conditions in order to assist material engineers in the choice of materials assigned to automotive exhaust systems. Cycle conditions were chosen to be representative of an actual vehicle use. The importance of spalling phenomena was confirmed. Due to their low thermal expansion coefficients, the ferritic stabilized grades behave fairly well, even in these rather severe high temperature conditions. The influence of nature and concentration in stabilizing elements (Ti, Nb) on the cyclic oxidation behaviour is pointed out.

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.

The addition of boron to steel introduces the possibility ofsteel initially completely solidifying and then remelting inthe interdendritic regions at very low carbon levels. For allcarbon levels, a low melting Fe-B alloy exists as a liquiddown to around 1100°C. This liquid is found in steel with aslow as 0.0004% boron due to the boron segregation. Thepersistence of this liquid leads to hot shortness, breakouts,and other casting defects. Pseudo-binary phase diagramsfor low boron concentrations have been developed usingThermoCalc software and were confirmed using experimentaltechniques.

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.