The initial solidification in the continuous casting process can be controlled by imposing a pulsative AC electromagnetic field on the meniscus. The casting experiment of a steel billet has been conducted by using a commercial billet caster. The imposition of a pulsative AC electromagnetic field has greatly improved the surface qualities. This presentation provides the results of the electromagnetic casting project of JRCM which is supported financially by the Ministry of International Trade and Industry of Japan.

The works described previously, and summarized here, have already been applied under various forms, to be described hereafter: explanation of industrial observations, knowledge models, new ideas for lubricant formulation, which now have to be tested. Of course, not all the needs of industry have been fulfilled, so that perspectives for further research are highlighted.

A goniospectrophotometer is used to analyze the back-scattered light, in the visible range, by a 0.3 cm2 surface. The measurement is non-destructive, without contact and can be implemented in situ. For a metallic surface, the reflected intensity is measured as a function of the back-scattered angle. The probability density of the normal to the surface is then deduced. The ratio roughness r.m.s. / correlation length is calculated. The method is applied to characterize the different techniques for gold backgrounds in primitive European paintings. For a non-metallic surface, the reflected intensity is measured as a function of the wavelength. The spectrum is compared with a data bank of mineral pigment spectra. The comparison allows to identify pigments and, moreover, to deduce the surface state of the painting layer. Examples of Egyptian and modern paintings will be presented.

The main operating results of the European blast furnaces in 1998 are presented. The parameters influencing the productivity of blast furnaces are recalled. In Europe, actions have been taken to optimize blast furnaces operation: composition and quality of the burden, burden distribution, tapping practice, etc. Further improvements of the operating performances are expected.

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.

The pickling line and cold rolling tandem mill at the Parrows Point Works of Bethlehem Steel Corporation are linked in a continuous processing complex. This complex has been automated by VOEST-ALPINE Industrieanlagenbau (VAI) through the implementation of a comprehensive package of innovative solutions. This project has contributed to improve significantly the quality parameters of the strips produced by the cold rolling plant (thickness, flatness, etc.) and to increase its yield.

This paper describes the first industrial application of the new DYNAFLEX oscillator developed by VAI on the two billet casting machines at Lech-Stahlwerke (Germany). Its main features are : no servohydraulic components, a system of leaf-springs arranged in cascade, simplicity of adjustment of stroke, frequency and wave form during casting. These factors suppress the need for maintenance of the oscillator, prevent mechanical backlash and result in a significant increase in machine availability and product quality, as well as in reduced maintenance costs.

Frequently, it is desired to preserve the original tones of copper, brass and bronze surfaces which are used in decorative areas. This can be achieved by applying clear protective coatings, acting as weather barriers and surface protections against mechanical aggressions. The performance of two clear coatings and a hard coating is evaluated, using a linear scratch test and abrasion tests. The hybrid sol-gel coating greatly improves the wear resistance of brass. The corrosion-resistant varnish tested has very poor wear resistance. Too thin and porous hard-coating layers have poor corrosion and abrasion resistance. The hybrid sol-gel coating gives the best compromise in terms of aspect, properties and cost.

The objectives and the context of the major maintenance work carried out on Cockerill Sambre's BF B and 6 are presented. After preparation and dismantling operations, the hearth of BF B was cleaned and relined. Simultaneously, the stock was partly equipped with copper staves. Good planning and coordination allowed the work to be executed in safety, within the schedule and with the required quality. The same principles have been applied for the repair of BF 6.

As leader of a consortium, VOEST-ALPINE Industrieanlagenbau (VAI) has supplied the hot strip mill complex of HADEED (nominal capacity of 800,000 t/y) on the turn-key basis. This complex delivers a wide range of products. The installations are characterized by a series of innovative solutions in the areas of mechanical technologies and automation. Already during the start-up trials, the operational performances have partly been well above the values specified in the contract.

Oxygen consumption in the EAF continues to increase, partly due to the development of various technologies based on supersonic lancing. This paper discusses the characteristics of supersonic jets and their industrial implementation. Based on fluid mechanics, numeric modelling and laboratory measurements, physical parameters which can act on the quality of the jet are reviewed.Alarc Jet supersonic injection technology has been designed to provide, in addition to high-standard burners and postcombustion tools, the best global efficiency of oxygen in the EAF. Application to the 160-t furnace of SAM Neuves-Maisons is described.

During 1999 and 2000, the six lines of the continuous billet casting machine of ISPAT Unimétal at Gandrange (France) have been equipped with the DIAMOLD moulds developed by VOEST-ALPINE Industrieanlagenbau (VAI). This transformation required no constructional change of the machine and represented only a minimum investment. The new mould technology allows to cast at very high speeds (above 3 m/min) and to comply with all quality requirements for a wide range of steel grades.

The hardness and wear resistance of 304 stainless steel have been increased by electric arc charging with two hyppereutectic alloy coatings. Oxidation tests have shown that, thanks to the presence of silicon in the coating, a protecting layer of Cr2O3 can develop, which leads to an oxidation rate similar to that of the substrate.

In the context of the development of a new concept of electromagnetic continuous casting of slabs, in which an alternating magnetic field (AC) with middle range frequency is combined with a continuous magnetic field (DC) in the vicinity of the mould meniscus, the study carried out by Irsid and EPM Madylam made it possible to develop numerical simulations for both the alternating and continuous magnetic fields. The calculations have been developed for the middle frequency range of alternating fields. They made it possible to correctly describe the average deformation of the free surface and the recirculation speed patterns in various AC configurations, as well as a good prediction of the damping effect of the DC magnetic field on the recirculation speed of liquid steel and the modification of the free surface deformation.

The limit condition for the flow rate at the wall for a Newtonian fluid with various solid/liquid interfaces was studied experimentally using an original high resolution technique. A notable interfacial slipping was shown for the hexadecane flowing on a surface with low roughness and covered with methyl groups (non wetting surface for the hexadecane). The systematic study of various modified surfaces made it possible to identify two key parameters fixing the amplitude of slipping at the wall and acting in an antagonistic way on the roughness of the surface (geometric and chemical) and the fluid/surface interactions.

In order to find the origin of the surface marks in meniscus free continuous casting, an experimental work has been carried out with two different experimental devices using metallic alloys and transparent organic compounds respectively. In a first companion paper, we showed the results of the observation of the samples obtained with the two devices. Here, we present the results of the direct observation of the solidification phenomena. These results permit us to propose a microscopic model of the formation of the marks.

Statistical methods have been used to analyze the thickness variations in coils of packaging steel. A sampling procedure has been defined in order to characterize the thickness variations in length and width directions for a given coil and from coil to coil. The analysis has allowed to evaluate the respective contribution of the various sources of scatter in relation with the production sequence and to define a strategy for the improvement of the results in this area.

C-Mn steels and associated welds are susceptible to Dynamic Strain Ageing (DSA). In this case, fracture toughness shows a minimum when the temperature increases from 20°C to 300°C. After a literature review, the results of J - R tearing resistance tests, characterized by crack initiation resistance J$_{0,2}$ and tearing modulus dJ/da relative to a base metal (A48 French standard steel) and Manual Metal Arc deposited metals are presented and discussed. The decrease of both crack initiation resistance J$_{0,2}$ and tearing modulus dJ/da is related to the DSA sensitivity of the material. A simplified engineering method based on the evolution of the Ultimate Tensile Strength versus temperature and a method of J$_{0,2}$ determination according to a local approach model of ductile fracture are proposed to predict the maximal drop in tearing resistance exhibited by the materials around 200°C as a function of ageing sensitivity of the product.

When producing ultra-thin hot strip, the yield and economy depend on achieving narrow geometrical and material properties fulfilling the increased customers demand. In production, the correct measurement of the strip properties is necessary. This paper gives advanced measuring and control techniques for the parameters concerning thickness profile, flatness profile, coil face profile, temperature profile, surface finish profile of ultra-thin hot rolled strip.

In May 1998, Muroran Works installed a near-net shape casting and compact high reduction (NCR) process in its steelmaking plant. The No.3 continuous casting machine was rearranged to cast middle cross section blooms, and a reheating furnace and a 2-passes high reduction breakdown mill were newly equipped. No.3 CCM casts square 220 mm mould size blooms and the breakdown mill reduces their cross section to square 162 mm. This combined process improved the quality of the cast billets and achieved high productivity.