The VAI Variable Speed Descaler takes full advantage from the use of variable speed pumps powered by inverter driven AC motors. Integration with strip tracking and feed forward pump control, together with direct application, allow to optimize the energy savings, to improve pumps life and to simplify the layout. Integration with flow and pressure feedback measurements at headers allows headers pressure tuning, nozzle wear compensation, process control with different “descaling recipes” as function of steel grade and main strip parameters, bar-to-bar adaptation of descaling parameters in case in-line surface inspection is present. Specific “descaling recipes” and pumping station design, together with proper mill scheduling, result in a new maintenance concept allowing to run the system without a stand-by pump, saving investment cost. First two references of this new system are at the hot strip mills of Ilva Taranto (HSM No. 1) (Italy) and of Duferco La Louvière (Belgium).


The modernization of a wide-strip hot-rolling mill with the doubleobjective of reducing production costs and satisfying the increasingdemands of the market represents a lower investment than theconstruction of a new mill, but is connected with the considerationof highly complex aspects. The authors present three projectsshowing the approach used by VOEST-ALPINE Industrieanlagenbau (VAI) and the results obtained.

Slag splashing is a way of maintaining converters lining, started at the Fos steel plant in December 2003. Systematic slag splashing on converters lining, by nitrogen injection with the top lance, after tapping, protects refractory. The aim of the project is to disconnect the two converters, from the refractory point of view, and to reach a refractory lining lifetime of 5,000 heats.

No. 8 CGL of TKS-CS was the first continuous production line where a laser welder was installed to weld full-hard material. The presentation describes the requirements for welder and weld in such a line. Decision criteria and welding tests are reported. Differences between laser welding in a CGL and in the automotive industry are shown. Results of 2.5 years of practical experience are summarized.

The 3rd octave chatter in cold rolling mills is a major issue for theindustrial production of thin sheets with very tight tolerances, likepackaging steels for instance. In this context, an experimental andtheoretical approach, completed in partnership by Arcelor and VAI,afforded a precise analysis and innovative results, in the followingfields : global on-line tandem mill instrumentation and efficient signaltreatments implementation ; clear differentiation between brummer (non divergent mode) and chatter (divergent mode) ; modelling ofinteractions between chatter and technology (analytical and F.E.approaches) ; advanced chatter monitoring and industrial implementation.

A physical limit to the galvanizing speed exists over which the liquid film explodes completely and prevents any further wiping. This limit is presently estimated around 180-200 m/min. A dimensionless approach including the Weber and Reynolds numbers is proposed to be able to predict the occurrence of the phenomenon. Practically it comes out that nozzles tilted by 30° down to the pot can pushback the limit by 30 %. A maximal line speed around 220 m/min could thus be reached.

The latest developments of laser cutting machines have facilitated the implementation of tubular assemblies. High capacity machines allow to consider a new assembly method by pre-cutting chords of lattice beams. Research was undertaken to study the implementation and technical aspects of this new type of assembly in order to validate it. Many advantages of the technique, a reduction of the manufacturing costs in particular, have aroused the interest of the stakeholders in the construction sector. Applications that will take full advantage of this new technique are expected in the near future.

A real time synchrotron analysis of the breakdown of the inhibition effect of the Fe2Al5 layer is reported. Both δ and δ−ζ Fe-Zn phases grow simultaneously when inhibition is suppressed until the Zn layer is consummated. Then the δ phase grows at the expense of the δ−ζ phase. The same mechanism is observed both below and above the Zn melting point. Phase transformations kinetics obey an Arrhenius type law that is not affected by the liquid or solid state of the Zn layer.

Led by increasing stainless steel demands worldwide, Avesta Polarit Tornio, now Outokumpu Stainless Tornio, decided to extend its slab production capacity from 650,000 to 1.65 million tons per year of cast products. To supply 1.0 million tons of additional slabs, a complete new steel plant was successfully started up in September 2002. The process route includes a 140 MVA electric arc furnace, a 150 tons AOD, a twin ladle furnace and the world most advanced continuous casting machine. Technological highlights together with operational results are presented.

The DSR (Dynamic Shape Roll), a powerful flatness actuator developed by VAI Clecim, has been installed and commissioned on the No. 1 tandem cold rolling mill of Baoshan Iron and Steel in 1997 and more than 4 million tons have been rolled with this equipment. This long operation period allows us to quantify the first operational results in terms of performance, capacity and operation of this actuator on a wide range of products. This also allows us to confirm the potential gains induced by this innovative technology with regard to the market changes and requirements.

Normalized steels are widely used in the pressure equipment industry and most of the safety rules have been established based on the properties of these steels. In the past, the use of quenched and tempered steels was limited to the biggest pressure vessels to achieve the mechanical properties at quarter or mid-thickness. The paper describes three examples of use of QT steels manufactured by Industeel and used in PWHT or in as-welded condition: the use of CARELSO 355 HRS (P355QL type) for pressure vessels operating in sour service and resistant to the SOHIC phenomenon; the use of SUPERELSO 500 HR (P500QL type) for pressure vessels operating in sour service (separators, scrubbers...) but when weight saving is of major importance; the use of SUPERELSO 702 for the racks of jack-up platforms and the results of P690QL steel grade in ECOPRESS research.

For pre-painted surfaces, contamination comes essentially from the air and it is important to have a relevant test to characterize the surface behaviour towards bacteria according to its conditions of use. A colour test is introduced that enables to detect active or dead bacteria directly on a contaminated surface. Means to avoid the proliferation of microorganisms are presented. The behaviour of two pre-painted topcoats doped with organic and inorganic bactericidal additives is described. On fresh and clean surfaces, the organic coatings have a very slight biocide effect. The weakest bacteria are rapidly destroyed whereas the more resistant ones are only inactivated several days later. On fouled surfaces, the bacterial destruction is very limited. In the selected experimental conditions, the standard pre-painted topcoat has the same behaviour as the doped ones.

The effect of a high magnetic field on the isothermal ferrite formation in Fe-0.15 wt.% C alloy has been evaluated by quantitative microscopy analysis. The isothermal ferrite transformation is accelerated under magnetic field, mainly because of an increase in the nucleation rate of ferrite.


Several investigations and developments have been made for automotive fuel tanks considering the demanding environmental situation. At Nippon Steel, hot dip tin-zinc coated steel sheet has been developed as alternative material for terne sheet for automotive fuel tanks. Tin-8wt%zinc was selected in view of its corrosion resistance, which is strongly influenced by the morphology of the zinc phase. Tin-zinc coated steel sheet has been widely used by Japanese automotive manufacturers because of its well-balanced characteristics.

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 high corrosion resistance afforded by Zn + 5wt.% Al coatings isfurther improved by low level additions of Mg in the galvanizing bath.The effect of Mg additions on the microstructure and on the properties of the coatings has been investigated. Phase field modellingwas used to simulate the influence of Mg on the eutectic microstructure. Experimental results on the effect of Mg on the ductilityand on the corrosion resistance of the coating are also reported.

A portable system to measure strip vibration at the nozzles level on continuous galvanizing lines is presented. It consists of three inductive sensors: two sensors are located near the strip edges and the last one is at the centre of the strip. This system has allowed reproducible results, provided the appropriate calibration procedure is used. The device has been successfully implemented on three lines of Arcelor. Considering the effect of strip tension and size, the frequency and amplitude measurements confirm the trends that can be expected from numerical modelling. Amplitude is always increased by the gas cooling power in the tower. Strip tension has a predictable effect on the frequency peaks; however its effect on amplitude is more ambiguous. Other observations have been made concerning the effects of pot roll bearings and roll intermesh.

Today, newly developed 9% Cr-steels, such as T/P911 and T/P92, are used for power plants with advanced steam parameters, thanks to their high creep rupture strength values. They show an increase of creep values by around 10 to 25 %, compared with T/P91. Nevertheless, their range of use is limited for high temperature because their oxidation resistance is lower than that of the classical 12%Cr-steels, such as X20CrMoV12-1 or the austenitic steels. In order to meet higher design parameters, a new steel, named VM12, has been developed by Vallourec and Mannesmann Tubes (V&M). The aim was to keep the high creep level of the T/P92 together with improvement of the steam oxidation resistance to fit with design steam temperature up to 650°C.

XPS and Auger spectroscopies are oflen used in several fields ofactivity of the steel industry that may be sorted into three items :defectology and expertise, research and development on productsand process, study of metallurgical mechanisms. In these fields ofactivity the results, that we provide our customers with, are obtainedwithin the frame of a "Quality insurance - Certification" approach.This approach is based on the appropriate measures taken byArcelor Research to give customers every confidence that any errorof measurement will be prevented. The few examples in this paperdemonstrate how XPS and Auger analysis, performed on samplesof small size to study phenomena at a nanometer scale, can be agreat help to the industrial line management.

The projects of Arcelor innovation R&D aim at developments having a time to market from a few months, for the most advanced, up to the end of the decade, for the most futuristic. They are carried out in partnership with the automotive industry. Ultra-high strength steels are a recent major innovation. They offer an effective answer to the request for improved safety and reduced energy consumption and contribute to sustainable development. The author introduces three major innovative developments: new technologies for high strength steels implementation, new openings for an improved cost/weight saving balance, new surface properties, based on nanotechnology. It is the ambitious claim of Arcelor, now and for the future, to afford steel solutions for all purposes, in particular for the automotive industry. The Arcelor-Nippon Steel collaboration makes it possible to bring an even better answer to the request of customers for further developments.