The rotating lance, tested in the CaO-Mg and CaC2-Mg processes,promotes a 20% and 30% increase, respectively, in the desulphurizationrate, a 50% reduction of temperature drop, and a reduction ofmetal splash occurrences. A criterion was developed that takes intoaccount the equipment dimensions and the mass flow rates of gasand desulphurization material, with the objective of transposing theresults obtained at Usiminas steel shop n°1 desulphurization station,to other industrial plants. Furthermore, it allows simulations to bemade with the objective of optimizing the pig iron desulphurizationprocesses that use the above mentioned materials as desulphurizationagents.

Oxygen usage has played a crucial role in the ongoing EAF processimprovement and has enabled furnace operators to optimize thechemical energy input, reaching unprecedented efficiencies and productivity.This article will present the fundamental principles governingthe design of an optimized chemical energy system throughscrap oxy-cutting and melting, decarburisation, post-combustionand slag foaming. It will be illustrated with industrial results obtainedat the Vallourec Mannesmann Saint-Saulve site, where a PyreJetTM and ALARCTM PC system, using the newly designed DRAGON Panel, has been recently commissioned.

A new technique for automatic assessment of centre line segregationbased on image analysis is presented. This innovative tool candetect both centre line segregation and centre line cracks from digitalizedsulphur prints giving an objective result. A data base containingprocess data from the caster and the new index for segregationmeasurement have been created. First analyses of this data base bydata mining tools have been performed showing very promisingresults.

New manufacturing technologies have been introduced by JFE SteelChita Works to increase the availability of seamless pipes with loweras well as higher thicknesses. For rolling the thinner seamless pipes,new plug lubricants and cermet coatings have been developed andthe roll gap control technology has been implemented. For rolling thethicker seamless pipes, a new plug has been designed that allows anew pass schedule through all mills. The quality assurance systemhas been improved with lower frequency ultrasonic waves.

LABEIN and ACB have developed a model to predict the mechanicalproperties of the hot rolled products, considering as a first stepthe hot rolling of thin slabs on the 7 stands hot strip mill (thin slabdirect rolling) of the Sestao steelworks.
The thermomechanical model includes a thermal module and adeformation module. It is supplemented with a microstructuralmodule and a mechanical properties module. The model has beenvalidated versus industrial results. It also includes an optimizingmodule that makes it possible to define the most appropriate processevolutions to meet new product requirements.

Four hot rolled steel grades were produced by the thin slab castingwith direct rolling technology at Acciaieria Arvedi S.p.A. (Cremona)and were coiled at two different temperatures. The steels are featuredby different chemical compositions: one is low carbon Al killedand three are high strength low alloy (HSLA) characterized by thepresence of Nb, V. The aim of the study is to investigate the influenceof the different coiling temperature on the mechanical and formabilityproperties as a function of the different chemical compositionsin order to exploit the potential of the plant. The results about theinduced strain aging appear interesting and are presented in thispaper.