Steel and steel composite bridges share a rather small part of the total bridge market. Nevertheless they are unbeatable for very longspan, extremely slender and/or movable bridges or in the replacement and/or widening of existing bridges. The reduced weight of steel bridges and of the steel structure of steel composite bridges allows a quick and cost effective erection by launching, lifting, a combination of both, rotation and the like.

PSA., leader in the fabrication of Diesel engines, aims at increasing its productivity for the manufacture of forged steel crankshafts and controlling perfectly their quality. All industrial partners of PSA are contributing to the achievement of this goal. Detailed metallurgical studies and numerical simulation have been used internally to describe the microstructural transformations involved. It has been shown that numerical simulation allows to identify trends for the effect of the modification of various parameters without the need for expensive and time-consuming prototype studies.

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.

An efficient way to increase the operational performance of hot strip mills is to lubricate the work rolls. A series of tests have been carried out at the hot rolling mill of Chertal (Cockerill-Sambre - Usinor). The main benefits which have been observed when using lubrication concern the reduction of friction and of rolling force.

The impact of the ferritic rolling schedule on oxide scale formation and on pickling rate has been compared to its austenitic counterparts. The effect of thin hot strip development on pickling plant productivity and on pickling cost price was also analysed. Different potential improvements to increase pickling rates were investigated and economical solutions are proposed.

Kawasaki Steel Corporation carried out a modernization project at the Chiba works No.2 continuous annealing line by linking the CAL with the existing skinpass mill and newly constructed facilities in the downstream area. Because the No.2 CAL and the skinpass mill are arranged in parallel, Kawasaki developed the world steel industry's first non-contact air floatation type strip turning device, called the "Helical turner".

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.

In Japan, automobile and steel engineers are working together for automotive body weight reduction. They are focusing on weight reduction from the point of view of both body structure and material. In order to meet the increasingly severe requirements for weight reduction, aiming at the limitation of the fuel consumption, an expansion in the range of application of HSS is vital. To realize further reduction, joint research by steelmakers and automobile manufacturers will become increasingly important.

The oxidation behaviour of a β-NiAl material (produced by powder metallurgy) was investigated in the temperature range 1200°C < T < 1400°C. In isothermal runs at 1200 and 1400°C, an alumina scale grew according to a parabolic growth law. At 1300°C, catastrophic oxidation was observed, but a short anneal at low oxygen partial pressure at 1200°C, prior to the oxidation at 1300°C, initiated a parabolic scale growth. Further, cyclic oxidation tests were carried out and the growth mechanism of the scale was identified by two-stage oxidation (16O2/18O2) in combination with SNMS isotope profile analysis.

Galtec, the subsidiary of Hoogovens and Sidmar, started the commercial production in February 1998. The CGL, located in Sidmar's cold rolling mill, is designed for applications in the building and white goods sector. The start-up curve was very steep ; more than 370,000 tons were produced during the first year 1998.

The restoration and preservation of metallic archaeological objects made of ferrous materials require the elimination of the chlorinated components contained in the corrosion products. Otherwise, after excavation of the artefact, corrosion will continue, sometimes at an accelerated rate. Different treatments may be applied for that purpose: electrolytic or alkaline sulphite baths, cold hydrogen plasma. This paper describes the hydrogen plasma treatment reactor in use at the Archaeological Museum of "Val d'Oise" , in France. Results of plasma treatments on artefacts are presented, together with optical measurements made at the reactor during the treatments.

Progress in bridge construction is partly due to the availability of improved steel products. In particular heavy plates, which can today be delivered in a wide range of dimensions and steel grades, enable bridge designers to achieve an efficient cost- and time-saving construction under simultaneous consideration of high architectural demands on aesthetics and elegance. Several examples will be presented which demonstrate the impressing opportunities of modern steel.

A very great number of arrowheads and arrows of catapult was excavated from "Le Puy d'Issolud" , probable site of the fight of Uxellodunum, given by Caesar, in 51 B.C. Till now, only a typological study was devoted to them. Here are gathered the first data about microstructure and local analysis (OM, SEM, EDXS, XR, microhardness HV) of weapons selected for their archaeological value. In the same time were made: examination of metal (Fe-C alloys, between pure enough iron and quasi-eutectoid steel), of corrosion layers and of the two types of residual slags, produced during direct reduction or forging. This contributes to reach a better approach of treatments and forging practice, during the Roman period.

An expert system model for a fume extraction system has been developed and installed at an electric arc furnace steelplant. Expert rules advise plant engineers of plant abnormalities that could result in fugitive emissions to atmosphere and/or result in excessive energy consumption. Neural network algorithms are incorporated into the model to mimic instrumentation and to analyse general trends. Since the installation of a prototype, significant financial savings have been made.

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.

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.

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.

Linked with the modernization of the steelmaking plants and the hot rolling mills at Chiba Works, the No.1 continuous pickling line was constructed, as a replacement of two old pickling lines and started its operation in January 1994. For efficient processing of material strips, which are getting increasingly thinner on market demand, the pickling line was equipped with a newly developed high speed pickling method, using a box dam-spray descaling, and various automated facilities, realizing the highest line speed in the world.

In view of the weight reduction strategies required and increasingly implemented by the automobile industry, growing importance is being attached not only to the materials but also the forming methods used. Forming processes using hydraulic media in particular offer the potential to produce more complex parts economically while optimizing component properties. The tube hydroforming (IHU) and hydromechanical sheet forming (AHU) processes are ideally suited for the production of automotive components in line with these requirements.

This paper aims to show different ways the original surface of archaeological metal artifacts can be preserved in the corrosion products. Depending on the corrosion mechanism, the original surface can be located thanks to some features used as clues: remains of metallurgical structure fossilized in the corrosion products, content of elements either coming from the soil or from the original alloy, cleavage occurring at some corrosion interface. Moreover, some of the features of the corrosion layers can be compared to what happens at the very beginning of the corrosion, despite a relative gap in knowledge regarding the very long-term corrosion mechanisms.