Salzgitter AG has a crude steel production capacity of more than 8 million tons. Its subsidiary Salzgitter Flachstahl GmbH produces hot strip, thin sheets and surface finished products as well as input stock for heavy plates and sectional steel. In February 2003, Salzgitter Flachstahl GmbH awarded a contract to SMS Demag AG for the supply of a single-strand slab caster including the building portion and all ancillary equipment under SMS leadership. A range of as many as 400 steel grades is cast on the two already existing bow-type continuous casters. The new caster has enhanced the grade range by adding in particular phosphor-alloyed and high-tensile steel grades, including HIC resistant as well as IF and C steel. This caster had to be designed in such a way as to be suitable for taking over production of one of the two existing casters in the longer term. Other goals of constructing a new, third slab caster were to increase the annual production rate of all three casters to a total of 4.7 million tons, to cut production costs, to improve the product quality and to safeguard slab production during the standstill and scheduled maintenance of one of the existing casters.

The coefficient of friction is one of the tribological factors that characterizethe process of multi pass hot rolling. Friction is strongly dependenton inter-pass and in-pass rolling and cooling processingparameters. It can be improved by application of hot lubricationunder specific conditions. This paper builds upon previous studies onthe application of a Coulomb-Norton friction mathematical model, tostudy the influence of hot lubrication for a range of rolling conditions,with a view to define conditions where lubrication is most effective.

The observation and Raman analysis of the surface of a PET polymer after the impact of an aluminium particle, combined with thermal modelling, have shown the presence of a zone with modified crystallization. This heat affected zone, with a thickness of a few microns, has different shapes depending on the geometry of the splat particle which is at its origin. This is the sign of a sharp temperature increase followed by a very rapid cooling. As a result, the proposition of crystallized phase is gradually decreased, and an amorphous phase is formed in a thin layer close to the surface. These results have been used to develop a protective plasma spraying technique for the coating of organic parts.

Ce travail est dédié à l’étude de l’endommagement en fatigue polycyclique soussollicitations multiaxiales de matériaux métalliques, suivant deux objectifs. Le premierest la caractérisation expérimentale de cet endommagement, pour des sollicitations simples(traction et torsion), mais également pour des blocs de sollicitations différentes. Lesecond objectif est la modélisation des phénomènes observés incluant l’usage de lamécanique de l’endommagement.

Cette modélisation est établie dans un cadrethermodynamique, suivant une description mésoscopique de la plasticité cyclique, avec uncouplage fort des variables décrivant le dommage cristallin. La version isotrope présentéeici utilise deux variables distinctes pour décrire l’endommagement du cristal. La premièrevariable permet de considérer les effets de la dégradation du cristal sur ses propriétésplastiques, alors que la seconde est une mesure équivalente de l’usure du cristal.L’évolution relative de ces deux variables dépend en premier lieu de la part hydrostatiquedu tenseur mésoscopique des contraintes.

The mechanism of cleanness improvement with bubbles isreviewed. Bubbling through the down-leg snorkel of a RHhas been modelled. This process was then experimented ona RH in POSCO, allowing a significant reduction of theinclusion content of slabs.

A closed-loop blast furnace automation system was jointly developed by VOEST-ALPINE Industrieanlagenbau (VAI) and VOEST-ALPINE Stahl Linz (VASL). The system, with the tradename VAiron, makes not only the operation of the blast furnace entirely transparent, but stabilizes it also, and permits therefore significant improvements in the regularity of hot metal quality and substantial reductions in production costs. The final goal of the development is the "fully automatic blast furnace" .

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.

This paper describes innovative solutions developed by VOEST-ALPINE Industrieanlagenbau (VAI) for bar and wire-rod mills and concerning mechanical equipment as well as automation systems. Among them, the Precision Rolling System (PRS) was first implemented at Chaparral Steel (USA) and the Minimum Tension Control is applied at BMZ (Belarus). Benefits are: improved product quality, greater mill availability, increased flexibility and productivity.

After presentation of the history of oxygen steelmaking, with special emphasis on the LD process, the numerous further developments and variants of the converter process are discussed. Finally, a tentative synthesis between electric and converter steelmaking is proposed. The article ends with considerations on the future of oxygen converter technology.

At the design stage of engineering structures, the fatigue behaviour is generally not included in the analysis. Shoulder reinforcements may be machined with too small blending radii. Even if fatigue is taken into account, the influence of the environment is almost always ignored. This paper shows that corrosion-fatigue is not an uncommon cause of failure in industry and that it may result in significant damages. The survey of such failures and the observation of the fracture surfaces allow to identify the typical features of this phenomenon.

Life Cycle Assessment is a powerful method to compare thefull environmental burden assignable to products, services orprocesses. In the framework of ULCOS project, this methodwas chosen to assess the environmental burden of futureiron and steel making processes. We propose here a novelmethodology which consists in replacing the traditional datacollection by a rigorous physico-chemical calculation. Suchan approach allows precise environmental assessment ofexisting or future processes.

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 newly developed VAI-CONR Chem system allows to determine continuously the chemical composition of liquid steel in any metallurgical vessel. It represents an enormous potential for process improvements. After extensive laboratory testing, the system was sucessfully tested at an industrial vacuum degassing plant. At the beginning of 2003, it will be installed at a new AOD converter.

Homogeneity methods are very helpful in the interpretation of X-ray line shift and broadening. The use of self-consistent models becomes general, but the information given by these models, which is shown to be strongly linked with diffraction measurements, can not yet be completely exploited. It is in particular shown that the intra-phase heterogeneity of strains should in certain cases be reflected by the line broadening behaviour.

Sun Coke Company's heat recovery cokemaking technology has been developed over the past 40 years, and is now poised to become the dominant technology to meet future global cokemaking needs. An extensive data base regarding coal blends tested and resultant coke quality will be presented. On the environmental front, extensive air emission data has been collected and will be compared to by-product coke plant air emission data.

Steam ejector vacuum pumps (SVPs) are mainly used on larger melt sizes up to 350 t inintegrated steel plants because of the availability of steam. The use of dry operatingmechanical vacuum pumps (MVPs) for steel degassing has made a tremendous step forward inthe past 10 years but is still confined to melts below 150 t while its progress towardslarger melt sizes is not completed. Besides the consideration of investment and operatingcosts there is no restriction in using any type of modern vacuum pump system for allvacuum processes and plant designs. Both systems fulfil all metallurgical requirements.Considering the significant savings in operating cost offered by MVP systems it is worthreconsidering the efforts for reducing air leaks, the use of protective gases and pressurelosses between the pump set and the metallurgical reaction vessel. Both systems have madeprogress in energy optimising but the MVPs have a striking energy advantage. Only theoverall costs should be considered, including those necessary to meet emission constraintsand safety standards, and only the pressure prevailing at the reaction vessel is to beconsidered when comparing vacuum pump systems. Also, the means and use of dust abatementsystems should be reconsidered since they offer cost savings by reducing the frequency ofcleaning, less wear, little sludge handling and the significantly lower design suctioncapacity of SVP systems. The SVP mass flow need is to be corrected by a specialcoefficient before being applied to the volume conveying MVPs. Depending on theoperational pressure required for the pump design, MVP systems can reach the sameperformance at the reaction vessel with much less mass flow capacity than that needed by aSVP system.

Since 1953, under successive 5-year development plans, the structure and the production level of the Chinese steel industry has considerably changed. Although the share of flat products has increased, China remains a net importer of these products and other high value added products. In connection with the development of the consuming industries, the Chinese steel industry is undergoing important transformations, in structure, technology, capacity and efficiency.

The principle of mass flow AGC of tandem cold mill as wellas advanced mass flow AGC are introduced and analyzed.Based on advanced mass flow AGC, the effect of laservelocimeters to jointly control strip's thickness is analyzed.On the basis of the advanced mass flow AGC systemof tandem cold mill in Baosteel, the characteristics andmerits of advanced mass flow AGC in application of laservelocimeters are analyzed in detail.

The technology of slag processing by rotary cylinder at Baosteel has many advantages, such as short flow, higher efficiency, more safety, lower consumptions etc. Processed slag has stable properties and small but symmetrical granules, lower contents of free-CaO, and it can be used directly in many areas.

The Business Intelligence (BI) aims at providing the operational, tacticand strategic levels with information in order to support managersand specialists through the practice of analysis and decisionmaking. The results of the project pertaining to the steel makingplant are reported.