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.

The coupling effects between mechanics and corrosion which are involved during corrosion-fatigue of metallic materials are analyzed through significant examples. Quantitative approaches for crack initiation and crack propagation are given and discussed in terms of micromechanisms. The introduction of localized corrosion- deformation interactions in damage modellings is proposed and further trends for numerical simulations are introduced.

Thanks to many technological developments, modern Steckel mills are not only characterized by increased capacities and extended product ranges, but can also deliver plates in addition to hot-rolled strip. Some recent examples of supplies by VOEST-ALPINE Industrieanalgenbau (VAI) show possible Steckel configurations and introduce the innovative solutions developed at these occasions. These examples demonstrate the flexibility and economical efficiency of this technology.

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.

A new method for controlling the BOF process is proposed thatinvolves the use of an original in blow heterogeneous sampler and adedicated laser analytical method. The aim is to deliver a fast andcomprehensive analysis of steel and slag collected by the heterogeneous-samplings. Combined with a metallurgical model, the dataobtained with the heterogeneous samples make it possible to dynamicallyassess the refining progress in order to allow a safe directtapping practice.

This paper deals with the influence of thermal strains/stresses causedby braking on the fatigue life of cast nodular iron disc brakes forrailway vehicles. The thermal stresses have been experimentallyderived and the durability has been assessed for a breaking loadspectrum comprising 6000 stop brakings from 200 km/h, 3000 stopbrakings from 160 km/h, 1500 stop brakings from 120 km/h and30000 usual brakings periods slowing down from 90 km/h.The fatigue critical areas have been identified and a redesign of thediscs made it possible to afford the requested service life of3×106 km.

Poly(vinylidene fluoride) (PVDF) thin films were subjected to tensile tests in plane strain over the temperature range from 65 to 115°C. At different elongation velocities using video real stress and strain, it was observed that, under such strain regimes, the neck-in starts perpendicular to the tensile axis and propagates towards the sample ends. The propagation kinetics was carefully recorded during the tensile tests. It was shown with simple hypotheses, that essential plasticity equations of the material can be determined via this method in terms of local effective stress (σeff) as a function of local effective strain (εeff) for every investigated temperature. The X-rays diffraction shows that the stretching of the sample of PVDF at a temperature lower than 72°C causes the transition from phase II to phase I.

The main components of the Castrip facility at Nucor are presented and the specific features of the twin-roll casting are highlighted with reference to conventional and thin slab casting.Nucor expected in February 2005 a monthly production of 25,000 tons of strips with an average thickness of 1.4 mm and a minimum thickness of 0.84 mm. Most products are utilized in construction application as light gauge hot rolled low carbon steel grades.
Nucor is now in the planning stages for a second Castrip facility in the United States and is exploring opportunities for utilizing the technology internationally through joint ventures.

The steel industry in Europe has demonstrated a major commitment to reduce the environmental burden of its activities. The investments in environmental protection can be estimated between 5 and 15 % of the total capital expenditures to improve the individual operations. These efforts are strengthened by the technological evolution of the steel making sector and by an increase of the recycling route. The new development of viable techniques is still required to further reduce the emissions to the air, mainly from sinter plants and to decrease the amount of waste. Finally, it will become necessary in the future to fundamentally rethink the use of reducing agents to reduce the CO2 emissions.

The hydrodynamics in an electrolysis pilot-cell has beenmodelled with the aim of upscaling the direct iron productionprocess based on the alkaline electrolysis of an iron oxidesuspension. Two dispersed phase flow involved in this threephaseprocess have been evaluated: the solid and the gasphase hydrodynamics.The suspension flow characteristics areevaluated from existing litterature, and available correlationsare applied to the case under study. The minimum velocityrequired for transportation of finely ground iron oxide alongthe cathode surface is fairly low, in the laminar regime,corresponding to minimum pressure drop.The behaviour ofthe oxygen phase produced on the anode is evaluated in attwo scales. First, the trajectory of a single bubble sliding onthe anode is depicted, predicting possible rising or draggingof the bubbles as a function of its diameter. The gas-phasepattern is then studied from litterature results for gas-liquidflow in pipes. A separation of the gas phase from the liquidis predicted, the lightest phase being in contact with theupper part of the cell. Obtained results confirm the potentialof the selected design for transportation of particles and gasrecovery with low energy consumption.

For advanced high strength steels for automotive application, the time between materials development and regular use in cars, trucks and similar vehicles is rather short. In contradiction to this, hot rolled plates made of high strength low alloy steels which have been developed many years ago still do not find application fields in structural steelwork although they offer impressive mechanical properties. In this paper we argue that inadequate design rules in civil and mechanical engineering prevent such modern high strength steels from displaying their lightweight potential. A technological approach to the problem presented in this paper is to apply damage mechanics models together with probabilistic safety concepts for derivation of new improved safety factors. However, a major obstacle in this process is that these new safety factors will have to be included in the design standards. The development of such standards contains both institutional and epistemic obstacles to including alternative safety models. Taking standardization in Europe as an example, the standardization committee is characterized by both national interest representation and attempts to stimulate European integration and competitiveness. At the epistemic level, different understandings of what counts as evidence for material safety may challenge and postpone adoption of new calculative models. Institutionalization and epistemology thus contribute to a framework for standardization that needs to be questioned in order for new approaches to be accepted. Such questioning cannot be done on the basis of developing new calculation models alone, but needs a clear social component of building coalitions around the inclusion of new considerations, for example those related to sustainability.

Steel slag is a steel-making industry by-product, currently used forseveral applications in substitution of non-renewable natural resources(e.g., crushed stone and sand). The major reason for conductingthis study at CST ArcelorMittal Brasil was to verify if any of the currentuses of LD and NP slag presented significant risks to the environmentand/or human health.

In this article, we briefly recall the physical mechanisms at the origin of the Barkhausen effect in ferromagnetic mediums and the thermoelectric power in conductor metals. We then present, for each of these phenomena, the measurement principles and their sensitivity to the microstructural state, notably in the case of precipitation phenomena and in the ones linked to plastic deformation. Finally, in the case of the formation of precipitates in an iron-based alloy, we show the complementarity of both techniques.

The rate of air oxidation towards 1,000°C of the Si3N4-bonded silicon carbide refractory is low. It is found that the porous nitride-bonding phase oxidizes mainly and that the SiC oxidation is negligible. The decrease of specific surface area, due to the growing of a dense silica layer, induces much slower kinetics.

This paper describes a simple and efficient method to identify Young's modulus of thermally sprayed coatings. The mechanical method is based on the cantilever beam test, without the use of a strain gauge, combined with a finite element numerical modelling and optimization technique. The influence of coating roughness was taken into account in this work. Several types of coatings were tested and their Young's moduli were calculated. A sensibility analysis was also performed.

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.

Bulk metallic glasses foams are under consideration as highly functional material, such as energy absorbers or ultra-lightweight parts, due to their porous structure combined with desirable strengths at relatively low densities. Also, the characteristics of high surface area of foams synthesized from metallic glasses make them viable candidates as emerging materials such as high-sensitivity sensors, catalysts or hydrogen storage media. In current study, bulk metallic glass foams were fabricated by extruding powder mixtures comprised of metallic glasses blended with various kinds of fugitive phases followed by dissolution of the fugitive phases in an aqueous chemical solution, for example HNO3, to yield the final porous structure. As a result of dissolution process, porous metallic glass having uniformly distributed micro-scale porosity was fabricated using a sequential synthesis technique beginning with composite particles comprised of composites of MG and a fugitive phase followed by consolidation of the composite powders via warm extrusion.

In continuous hot dip galvanizing, in particular with galvannealing baths, competitive reactions occur between iron, zinc and aluminium that may be affected by other elements such as chromium. Based on thermodynamics modelling and experimental descriptions, the zinc rich corner of the quaternary Fe-Zn-Al-Cr system is investigated at 460°C. The results obtained contribute to a better knowledge of the reactivity of steels in industrial galvanizing or galvannealing baths.

To control the generation of dust in a steelmaking reactor, it is necessary to understand the underlying physical mechanisms. An experimental device has been developed to study the main emission mechanism, i.e. the projections from bursting bubbles. We visualized the burst on liquid steel and quantified the subsequent emission. The chemical evolution inside the fume exhaust system is simulated by thermodynamic calculations : the key parameters for controlling dust mineralogy are the Fe/Zn ratio, the oxygen activity (p$_{{\rm CO_2}}$/p$_{{\rm CO}}$) and the temperature evolution.

Good stability of the steel strip is essential in galvanizinglines, especially in the rapid cooling section before the zincbath, where the strip is cooled and excited by high-speedgas jets.
The process parameters and the design have beeninvestigated in order to characterize the strip vibrationsphenomena and to define optimized solutions for improvingthe cooling performances of present and future galvanizinglines while reducing the strip fluttering in the rapid coolingzone as well as in the cooling tower.