Oxygen usage has played a crucial role in the ongoing EAF processimprovement and has enabled furnace operators to optimize thechemical energy input, reaching unprecedented efficiencies and productivity.This article will present the fundamental principles governingthe design of an optimized chemical energy system throughscrap oxy-cutting and melting, decarburisation, post-combustionand slag foaming. It will be illustrated with industrial results obtainedat the Vallourec Mannesmann Saint-Saulve site, where a PyreJetTM and ALARCTM PC system, using the newly designed DRAGON Panel, has been recently commissioned.

Because of the effects that they produce, grinding operations may modify significantly the surface of a material and change its properties. The major part of the plastic work of cutting is tranferred to the part being ground as heat. In the case of the austenitic stainless steel studied here, grinding leads to an increase in hardness which can be attributed to the superficial plastic deformation of the material. However, for the most severe grinding conditions, a change in the deformation process is observed leading to dynamic recrystallization. This process is characterized by grain growth and dislocation rearrangement under the combined effect of the temperature and the stress level reached during grinding.

1 GHz very high frequency acoustical imaging displays a micronic resolution. Owing to its nature of sub-surface imaging, it is well adapted to the characterization of porosity. Used as a means for quantitative measurements through acoustic signature processing, it provides sufficiently localized information to characterize the elastic properties proper to each component of a SiC/SiC minicomposite, the fiber and the matrix.

A neural network model, trained by a genetic algorithm, has been developed to study the thickened ends of the pipes rolled by means of two stretch-reducing mills. The forecasting of the model showed a good performance that avoids other complicated developments based on precise structural approaches that generally take a great amount of elaboration time. The neural network can be applied to build an automatic procedure for the definition of the production parameters to minimize the discarded material of the pipe that is not in the limits imposed by the geometrical specifications.

Fugitive dust emissions from open sources are difficult to quantify owing to the extended area covered by such sources and the range of activities that contribute to such emissions. In a novel approach, a network of continuous monitors was used to obtain real-time local PM10 data on an integrated works and these data were used in conjunction with a reverse-dispersion modelling technique to quantify stockyard PM10 emissions. The results obtained are discussed and other potential applications of this approach are outlined.

The scientific investigation involves the examination of copper alloy nails dated back tothe Roman Age. The artifacts were retrieved from a shipwreck discovered offshore Elbaisland (Italy). Further carbon dating measurements indicated the origin between 140 and300 AD. This work includes a brief overview of the ship’s routes and fortunes in order togive some context to the metallographic investigations. The experimental procedureinvolves the use of both Optical and Scanning Electron Microscopy (OM and SEM) coupledwith EDS and EBSD probes. The attention has been focused on the metallurgical features ofthe nails with the intent of casting some light on the metalwork processes of the RomanAge. The scientific trials revealed a “brazed” joint, which allowed to learn more aboutthe applications of this technique during this historical period. In addition, thetextural analysis yielded a strong work-hardening, evidence of an intense cold shapingprocedure in use by the Roman blacksmiths.

The FSBA (Flexible Shaft Backing Assemblies) has been developedfor a 20-high Sendzimir mill. This new shape control actuator wassupported by a shape analysis model based on the distribution ofgeometrical moment of inertia in the roll axial direction. The shapecontrol range was doubly extended by the introduction of FSBA. Itwas confirmed on an industrial mill that quarter buckles are suppressedunder a wide range of rolling conditions by shape control withFSBA and concave rolls.

ThyssenKrupp Stahl operates four blast furnaces with a hot metal production of up to 12 million tons per year in total. To minimize the costs in the cast house operation and to optimize the tapping performance, measures were taken to prolong the lifetime of the refractory lining of the troughs by a supreme effort. Extensive technical measures in the total cast house area with the aim of best economical efficiency were taken. This report shows the effects for the cast houses of the big Schwelgern furnaces.

Dans les secteurs industriels de l’énergie et du transport, les structures mécaniquessont soumises à de forts niveaux de contraintes dynamiques qui impactent grandement leniveau de durabilité de ces dernières. Dans un contexte de réduction de coût de possessionet d’extension de durée de vie, les industriels sont conduits désormais à bien maîtriserla fiabilité mécanique de leur produit. Pour ce faire et de part la nature stochastiquedes chargements dynamiques, les méthodes utilisées sont celles de la fatigue vibratoire,basées sur des représentations fréquentielles, tant au niveau du schéma modal de lastructure, qu’au niveau de la définition de ses processus d’excitation et de contrainte.De ces considérations techniques, le présent article fait le tour des méthodes de calculutilisées en fatigue vibratoire et compare les méthodes de comptage Peak-Valley (PV) aveccelles du RainFlow Counting (RFC), reconnues comme les moins conservatives et donc lesplus pertinentes, en terme de prédiction de durée de vie. En ce qui concerne les méthodesPeak-Valley, les modèles historiques de Rice [S.O. Rice, Bell Systems TechnicalJournal 23 (1944) 282-332; 24 (1945) 46-156] et deMiles [J.W. Miles, J. Aeronautical Sci. 21 (1954) 753-762],développées en 1944 et 1954, sont pris comme référence et comparés aux modèles RainFlowCounting de ces dernières années. Pour ce faire, l’étude comparative se basera notammentsur les approches empiriques de Wirsching-Light [P.H. Wirsching, M.C. Light, J.Structural Division ASCE 106 (1980) 1593-1607], et semi-empiriquesde Dirlik [T. Dirlik, Application of computer in fatigue analysis, Ph.D. thesis,University of Warwick, 1985], développées respectivement en 1980 et 1985.

Since its construction in 1979, the Steckel mill of the Brazilian steel producer Acesita has been modernized in successive steps in cooperation with VOEST-ALPINE Industrieanlagenbau (VAI). This continuous cooperation between the equipment supplier and the steel producer serves as an outstanding example of a life-cycle partnership.

The acoustic near field method consists in studying the alteration of the resonance curve of a horn whose tip, the probe, is immersed in the sample. The operating mode in a medium in which strong variations of the rheological properties take place, is modelled for two horn shapes, one with a conical probe, the second one with a stepped cylindrical probe. The experimental curves obtained during the cement setting prove the validity of the simulations. The sensitivity of the horn to a given step of the setting is achieved by adjusting the probe shape.

VOEST-ALPINE Industrieanlagenbau (VAI) has developed the VAI-CON Temp system for the continuous temperature monitoring in metallurgical vessels. The system has been tested for a variety of installations and has reached industrial perfection. It has many potential applications (from the electric arc furnace to the continuous casting tundish) and, thanks to the highly accurate results it provides, it allows a substantially better process control than the conventional, discontinuous measuring systems.

Stainless steels have sustained a continuous growth for these 50 years, based on their outstanding corrosion resistance properties. Their corrosion performance has been ever improved for a large range of environments. New grades with higher static or dynamic mechanical properties afford high quality parts at lower cost with modern fabrication technology. In the future, stainless steel should find further application in the transportation and in the water distribution industries. This growth might be impeded by the EU classification of alloys with over 1% nickel. Attention that is focused nowadays on nickel, may later on be drawn upon all metallic alloys, whose distinctive features should rather be acknowledged and which should benefit from the support of a common strategy to be agreed upon by all stakeholders.

The control of oxygen and fossil fuels injections, taking into accountreal furnace conditions at each step of the melt, is essential for EAFimprovement. Based on near IR Laser- diode spectroscopy, a systemenabling dynamic and continuous CO and CO2 monitoring of EAFfumes during the whole melt for long-term operations has been developed.Several industrial trials are reported, the technology is describedand the results are discussed.

The influence of long-term ageing in NaCl on the passivity and electrochemical behaviour of UNS S32304 was studied. The passive film thickness, the Cr/Fe ratio and the chloride content were significantly increased after ageing. The chloride distribution depends on residual stresses, the sample microstructure and surface preparation. Local electrochemical measurements revealed that pitting potentials are between 250 and 550 mV vs. SCE after electropolishing. The higher the chloride content, the lower the local pitting potential. It was also shown that the presence of chloride was balanced by the enrichment in chromium after ageing. Then no pitting potential could be measured.

A novel web-based Decision Support System (DSS) for condition monitoring and continuousimprovement of steelmaking production efficiency is presented in this paper. Productionefficiency was measured and modelled through Key Performance Indicators (KPIs), which areassigned on-line to a single product (coil) and identified at different facilitiesthroughout the integrated route. The systemic nature of the DSS system boosts theintegration of every agent included in the decision chain of the company. It assuresmulti-agent decision convergence and the transformation of process information and expertknowledge into profitable results. The first case study is presented.

Dynamic modeling, as an effective decision support tool, is illustratedby the coupling of two continuous lines. The method stands outas general and easily transferable. Modeling makes it possible toassess the impact of various managerial decisions within a globalindustrial environment. Modeling is a preferred tool to extract knowledgefrom data bases, to formulate and to test new ideas.

The production of new steel grades - such as dual phase and TRIP steels - requires improvements to both process and equipment of continuous galvanizing lines. In particular, progress has to be obtained in cooling technology in order to get the desired mechanical properties. This paper presents a study of design parameters allowing the optimization of fast gas multi-jet cooling systems. The thermal study involves the application of infrared thermography and three-dimensional numerical simulations. Furthermore, a dynamic study is performed in order to reduce steel strip vibration.

Une démarche de développement d’un modèle probabiliste à deux échelles pour la fatigueHCF des aciers est proposée. Elle est basée sur l’utilisation de mesured’auto-échauffement sous chargements cycliques et est validée sur la base de la prévisiondes courbes de Wöhler d’un acier dual-phase pour différents rapport de charge.

The accuracy of the parameters is of great importance in the calculation and simulationof the COREX process. Therefore, it is necessary to measure some parameters, especiallythe heat loss and its distribution, which have not been reported before. Based on thecharacteristics of the two sets of the Baosteel COREX-3000 process, a method and standardare established for the heat loss and its distribution. Then the heat loss anddistribution are calculated based on the measured parameters. The results show that thetotal heat loss of the two COREX processes is 495.4 MJ/tHM and 413.7 MJ/tHM. The heat losscaused by cooling water accounts for more than 93% of the total heat loss while the heatloss of furnace shells is less than 7%. The main heat loss caused by cooling water takesplace at the tap hole zone, which is also the part of the COREX system with the most heatloss Its heat loss is about 30% of the heat loss caused by cooling water and 28% of thetotal heat loss of the COREX system. The main heat loss of furnace shells takes place atthe dome of the melter-gasifier and the reducing gas entrance position of the shaftfurnace, where the heat loss accounts for nearly 90% of the heat loss of furnace shells.It is also found that the energy utilization efficiency of the 1# COREX system is muchlower than that of the 2# COREX system after comparison.