The Arcelor plant in Dunkerque depends on external coke for onethird of its total coke consumption. A global approach has been carriedout:
To assess the effect of coke properties on the blast furnaceperformance.To specify the requested coke properties.
Appropriate coke characteristics have been defined, aiming at highblast furnace productivity (63t/m2/d), at high PCI rate (210kg/thm forall three blast furnaces) and at low consumption of large coke(230kg/thm).

Aceralia blast furnace A suffered a 28-days emergency repair inSeptember 2004, due to accelerated wear of the hearth walls andsevere damage of the cast iron staves at the bosh area. Consideringthe shortage of supplies, Aceralia resorted to non conventionalrepair methods in order to prolong the campaign by one year, untilfull relining: small format carbon bricks and carbon ramming massfor the hearth and tapholes and steel staves at the bosh.

Standard EAF operate with a large amount or air ingress (on theorder of 30 000 Nm3 for 150 t of steel). This air is at ambient temperaturethus, the nitrogen content and the non-reactive oxygen areonly heated through the furnace and exit with the fumes at high temperature(1000°C). This brings about significant thermal losses.Reference and airtight trials were carried out with the 6-t EAF ofArcelor Research for assessing the gains related to airtight furnaceoperation.

Transverse cracking may occur in high strength low alloy CC slabs.This phenomenon is associated to a hot ductility trough resultingfrom intergranular ferrite that forms at the beginning of the γ-α transformation. Sumitomo has developed a hot tensile machine and aunique slab surface microstructure control process to improve hotductility. The process based on controlled accelerated secondarycooling has been successfully implemented on Kashima n°2 caster.

Medium-slab casting combines all of the benefits of conventionalthick-slab casting and some of the benefits from thin-slab casting.The medium-slab caster incorporates the proven equipment design,operational aspects and automation features from conventional casting.

The features of dynamic transformation for grain refinement of lowcarbon steels are presented and representative results of trial hotstrip productions are reported. Laboratory experiments have establishedthat dynamic transformation occurs in under-cooled austeniteunder suitable deformation conditions. Trial production resultsshowed that utilizing the dynamic transformation concept, grain refinementof ferrite is feasible in commercial hot strip mills: a ferritegrain size of 2~3 μm can be obtained, along with various controlledsecond phases.

The origins of environmental issues are presented with an analysis oftheir influence on French regulation for the building sector. The environmentaladvantages afforded by steel are described for all stepsof the building life, design, construction, service, dismantling, alongwith the essential aspects of steel recycling and steel making.