Today's steelmaking is constantly challenged by increasing quality demand and the term “Clean Steel” has gained more and more ground. In many steel plants, slag carry over from the ladle into the tundish is negatively influencing the quality of steel. When the casting starts, the steel flows undisturbed through the defined bore of the seating block and inner nozzle, the whole cross section of the bore filled with steel, but due to the vortex-effect a slag core appears in the centre of the steel stream towards the end of the casting. The solution is the Clean Steel Block, a combination of seating block and purge plugs in the corners. First trials in different steel plants indicated that the installation of the Clean Steel Block will constantly suppress the vortex-effect and increases the quality of the semi-finished product.

For vacuum tank degassing, dynamic process models for dehydrogenation, denitrogenation, desulphurization, decarburization, the course of steel temperature and the removal of non-metallic inclusions were developed. They were validated by comparison of simulation results with measured process data from different vacuum tank degassing plants. The models are applied for on-line process observation, providing the operator with information on the current heat status, which is normally not available during the degassing process under vacuum.

In the mathematical model of the VAR process developed at Nancy, the coupled transport equations are solved in transient conditions, using an evolutive mesh for the ingot. The turbulent flow of the liquid metal is described by a k-ε method. The main physical phenomena included in the model are: latent heat dissipation, solute partitioning at solidification and liquid flow in the mushy zone. The model allows to represent the entire cycle of melting and electromagnetic stirring, and to relate directly the operational parameters to the metallurgical quality of the product. After validation, it has been implemented in a simulation software for an industrial sequence of triple VAR remelting. This software is currently used in industry.

Electric Arc Furnace (EAF) steelmaking generates fumes that must be captured for economic and environmental reasons. The fumes exhaust control at the EAF must be adapted to the process in order to fulfil the steel plant requirements and to meet the environmental regulations. It is in this context that Irsid has implemented, on 6 EAF (5 in France and 1 in Belgium), a strategy of advanced control associated to a representative instrumentation of the fumes emissions. An on-line defect detection algorithm is added to the pressure control in order to improve its reliability. Latest results obtained in Le Creusot have shown that the fumes exhaust control has a direct impact on the EAF ratios with a reduction of energy consumption, a reduction of electrode consumption and a reduction of the amount of dust recovered in the filters.

This paper describes various technological packages developed and implemented by VAI to help steel companies raise product quality, increase reliability and lower operating and maintenance costs for slab and bloom continuous casters.

Good control of steel flow through the submerged entry nozzle (SEN) during the continuous casting process is essential for improving surface quality and reducing cleanliness defects. Argon bubbles, biased flow and alumina deposits may all contribute to actual flow differing from the ideal case. The steel flow visualization project aims to penetrate the “black box”, which is the SEN, using electromagnetic techniques. A sensor array consisting of transmitter and receiver coils is positioned around an SEN and the resultant signals are compared to those from pilot plant measurements designed to simulate known continuous casting conditions.

Steel velocity measurement in the mould has been carried out using a Karman vortex flowmeter. The sensor is based on Karman vortex streets, which occur when a flowing fluid encounters a fixed body. A linear relation exists between the velocity of the fluid flow and the shedding frequency of Karman's vortices, therefore by measuring the frequency, the velocity of the fluid flow can be calculated. The system consists of two consumable sensor rods, which are placed at either side of the SEN. With the end plates instrumented with additional thermocouples, it is possible to relate the differential velocity measurement to end plate temperatures.

ACB was the first thin slab casting and coiling plant in Europe, using CSP technology and up to now is the only CSP that uses steel from an electric arc furnace. The evolution of process and products in these facilities are presented from the start up in 1996 to the present situation. Particular attention is paid to the development of microalloyed, electrical and weather resistant steels, the improvements of surface and internal quality and the modifications introduced in the plant to improve productivity. Furthermore, geometrical aspects and thin gauge rolling are discussed with a view to develop 1 mm hot rolled coils.

This article describes the study of the impact of aqueous discharge from the Fos-sur-Mer steelworks on the Gulf of Fos on the shores of the Mediterranean sea. Such a study provides information on which to base prioritization decisions for environmental action: for example, the eutrophication power of the nitrogen-bearing effluent from the coking plant led to the addition of a cleaning system operating by nitrification/denitrification.

Drying and curing procedures of both organic and inorganic coatings by high frequency induction heating have been developed on a pilot scale. The furnace has been integrated in a continuous coating pilot line that includes a decoiler, a welding machine, a roll coater, convection furnace and a wind up roll. Thus, the complete coating process, including post treatments can be simulated, in particular for automotive applications. The first results obtained on organic and inorganic coatings with this fast curing procedure are presented and compared to those obtained with convection furnaces.

The different ULSAB programmes offer steel solutions to the challenges facing automakers around the world today: increase fuel efficiency, improve vehicle performance and maintening affordability. In the ULSAB-AVC programme, the complete body structure consists of high strength steel with over 80% being advanced high strength steel grades. Application of advanced technology such as tailored blanks, tailored tubes, sheet and tube hydroforming, and extensive laser welding was also coupled with innovative design. The design and manufacturing features of ULSAB-AVC body structure are presented along CAE analysis and economic analysis results.