This study concerns the inhibition of the corrosion of the aluminium alloy 3003 in a solution of 3% NaCl by Li+, Mg2+, MoO42-, NO2- and CrO42- ions. The methods used are the determination of the polarization curves and the metallographic examination of the surface condition. The results obtained show that the tested ions inhibit the corrosion process.The comparative study of the effect of these ions shows that the Mg2+ ions are the most efficient ones in the temperature range from 25 to 65°C. The inhibition efficiency increases with the concentration of these ions and reaches a maximum value of 86% for 5 × 10-2 alloy. As a consequence, the gap between pitting and corrosion potentials becomes larger. At 75°C, Mg2+ ions tend to stimulate corrosion of alloy 3003 in the chloride solution considered.

The efficiency of automatic flatness control systems in tandem cold mills is mainly based on the accuracy of the prediction models and on the selection of optimum control concepts. BFI, together with EKO Stahl, has recently developed and partly applied advanced flatness control strategies (providing online-adaptation of actuator action to thickness profile information and in-gap process condition towards a fully integrated flatness control of all stands) that are superior to conventional techniques and lead to significant improvements in strip flatness. The present article aims to demonstrate the principles, advantages and results of this work.

In horizontal continuous casting or in meniscus free continuous casting, the appearance of corrugations or marks at the surface of the cast products cannot be related with the partial solidification of the meniscus of the free surface of the liquid metal, like in the case of the classical vertical continuous casting process. In order to find their origin, an experimental work has been carried on with two different experimental devices. The first one provides solidified metallic samples to be observed and analysed. With the other one, it is possible to directly look at the formation of the skin on the mould during the solidification of transparent organic compounds. Here, we firstly present the results of the observation of the surface of samples cast in very different casting conditions. In a companion paper, we propose a description of the formation of the marks and corrugations in terms of basic phenomena which occur during solidification.

In the last few years, CPM developed a first generation of charging model for coke ovens to improve the uniformity of oven filling and to reduce charging emissions. A new charging model has been recently built to simulate all kinds of charging process with 3, 4 or 5 charging holes and to obtain a more reliable representation of the levelling operation. More particularly, coal accumulation in each compartment of the leveller bar is represented, in order to have a better idea of the gas free space during the levelling operation. By using this model, it is now possible to suppress or reduce coal accumulation in the oven free space during the levelling operation and to obtain a constant and uniform coal profile at the end of charging, without gas emissions.

Improvements have been made to slab, bloom, billet and thin slab caster secondary cooling systems giving better control of strand surface temperature and quality. This has been achieved by a combination of laboratory-based tests of spray characteristics and heat transfer coefficient (htc), innovative mathematical modelling and detailed on-plant measurements of temperatures and spray conditions.

Based on the balance equations of mass, partial mass,momentum and thermal energy, the pyrolysis processof non-coking coals using a counter-rotating twin screwreactor (TSR) is modelled by means of commercial CFDcode PhoenicsTM. In favour of good convergence of themathematical solution, a structured, cylindrical-polar gridis chosen. Variable filling and intermeshing degrees aretaken into account by blocking numerical cells in gasdomain and intermeshing domain instead of performingtwo-phase calculations in a body-fitted co-ordinate system.Viscous behaviour of the granular coals is expressed bymeans of a generalised Newtonian fluid and chemicaldecomposition is implemented with aid of distributedactivation energies.

Physical model experiments were performed to clarify the influence of orifice configuration on the volumetric mass transfer coefficient during ladle purging. Bubble behavior was recorded by a high speed video camera in the present study. And carbon dioxide desorption from an aqueous NaOH solution was used to measure the volumetric mass transfer coefficient. It is found that bubbles for multi-hole orifice are generally smaller than those for 1-hole orifice. However, when the hole distance in the multi-hole orifice is too short to avoid bubble coalescence, large bubbles will be formed. It is shown that there is a decreasing tendency of the volumetric mass transfer coefficient when the hole diameter increases. The volumetric mass transfer coefficient firstly increases with increasing the hole distance and hole number. Thereafter, it remains approximately constant with further increase in the hole distance and hole number.

Industrial trials were carried out at the ArcelorMittal Isbergues slab continuous caster with the HJN (Hollow Jet Nozzle) previously developed at CRM at the pilot stage. This nozzle allows the addition of fine metallic powders in molten steel right before its solidification. These tests showed the possibility to implement the nozzle in an industrial stainless steel slab caster. It was observed a full melting of the injected elements (Fe and Fe-Ti), a homogeneous distribution of titanium element in slabs and a drastic improvement of the addition yield of titanium.

The E911 steel grade has been developed from grade P91 to increase the creep properties at 600 oC through the control of vanadium, nitrogen and the addition of tungsten. Grade 911 shows a better creep performance than grade 91. Microstructure stability of both steels was investigated by isothermal ageing tests for up to 10,000 hours at 600 and 650 oC and their mechanical behaviour is compared. Results on welded joints have also been compared with base material.

The Production of aluminium is one of such industrial processes that have the potential to release great quantities of dangerous toxic material into the atmosphere. To protect the environment, the Alucam Company has put in place two collection and treatment stations. The main indicator of performance of this system is the collection and treatment efficiency. All other parameters kept constant, this efficiency is proportional to the fume flow rate at the chimney. But the key parameters to control in case of variation are poorly mastered. The collection efficiency of the treatment stations can deteriorate at any moment without any successful intervention to bring back the situation to normal. This article presents the first part of a research work which intends to solve this problem of variations in the flow rate by increasing the fume flow rate and controlling the system within specified limits. We use a Continuous Improvement Methodology which involves the use of Six Sigma tools at the completion of the analysis phase of which we get the fundamental causes of the low performance.

Classically, the simulation of primary recrystallization and grain growth starts from a theoretical microstructure defined numerically and characterized by a random texture distribution. The results obtained in this way represent well the overall behaviour of the material during annealing, but do not allow to obtain a local description, consistent with reality. In such procedures, a perfect homogeneity is assumed both for microstructure and for texture, which is generally not observed experimentally. For this reason, the authors have proposed in recent years to combine simulation and experimental observations; the calculation starts from the real microstructure characterized by TEM or by OIMTM. The first simulations of this kind carried out have shown that such an approach is feasible and has a great potential. These results are summarized and discussed in this paper. There are limits to this approach, related in particular to the lack of experimental data on the strain energies stored in the grains after deformation and on the energies and mobilities of grain boundaries.

The development of steel refining operations at ArcelorMittalFCWE for the production of ULS steels is reported. Several plants with different equipments produce grades with S <30 ppm, thus permitting to identify the most efficient process, from hot metal desulfurization to secondary metallurgy. For sites producing steels with S <30 ppm, four secondary metallurgy routes coexist in ArcelorMittal FCWE. The Vacuum Tank Degasser makes it possible to reach very low S and N contents simultaneously. To face the increase of the share of Ultra Low Sulfur products, it is necessary to further enhance the kinetics of desulfurization by steel - slag stirring at the atmospheric pressure.

The recent projects and the new EAF orders indicate a newtrend in the furnace design proposing very big electric arcfurnaces. Concast, after the first successful installation in2003 of the 180 t EAF in Icdas, wants to reproduce the reallyoutstanding performances of this EAF with the new 220 tEAF producing 320 t/h. The equipment installed and thefurnace design will follow the “Ultra High Chemical Power”EAF indexes.
An analysis on the basic engineering parameters and theextrapolation of its performance are presented.

Examples of high cycle thermal fatigue (HCTF) damage cases onPWR austenitic stainless steel components are reported. High cyclethermal fatigue risk is primarily due to mixing of cold and hot water,unexpected leaks of cold water through check valves or to turbulentpenetration of hot water running in a main pipe into a connected line.When such thermal fatigue issues are identified in PWR powerplants, manufacturing improvement such as inner surface polishingof austenitic stainless steel parts can be performed to increase thefatigue resistance of the components.

VAI-Q Strip is a quality control system, based on physical-metallurgical models, for hot-rolled strip. This joint development of VOEST-ALPINE Industrieanlagenbau and VOEST-ALPINE Stahl Linz allows the automatic on-line control of the mechanical properties using very accurate prediction methods. Since the beginning of 2000, an extended version of the system is in operation at VOEST-ALPINE Stahl Linz and very good quality results, as well as cost savings, have been achieved.

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.

The attachment mechanism of inclusions to bubbles hasbeen studied with water model experiments under turbulentcondition. Change in particle-number concentration indicatesthat the removal rate follows first order kinetics. It increaseswith particle diameters and particle contact angles.

Production processes of integrated steel plants, mostly based on coal as an energy source, produce about 2 tons of CO2 per ton of steel. As specific CO2 production has to be decreased by 20% in the mid-term (2020), immediate action is required to further decrease the specific energy consumption. The integrated plant is not energy self-sufficient as extra electricity must be bought from outside, but on the other hand, produces an excess of process gas that has to be used within the plant. Optimisation of the use of the internally produced gases is a key issue as either they are burned at the power plant with a conversion yield to electricity of about 40% and often much lower, or might be valued in the plant internal heat exchangers with a much higher efficiency such as  ~90% in the hot stoves or  ~65% or more in the present reheating furnaces. This paper shows that using the high-value coke oven gas as a chemical reactant (for DRI production) leads to significant extra metal production. From a global viewpoint, this extra metal production is almost carbon-free, as it requires only electricity for its manufacture.

Copper single crystals with the {110}[001] initial orientation were cold rolled and subsequently compressed in a channel die with the new direction of plastic flow parallel to the former transverse direction of rolling. The texture formed during subsequent recrystallization showed components which were not characteristic for the texture of the deformed matrix. Shear bands were formed after the change in the direction of plastic flow. Recrystallization commenced within shear bands and proceeded by the growth of selected grains into the deformed matrix. Measurements of the local crystallographic orientations indicated that the processes predicted by the theory of oriented growth played an important role in the formation of recrystallization textures. The orientations of the fast growing grains could be produced as a result of the formation of recrystallization twins.