In Europe, like elsewhere, the share of steel produced by electric arc furnaces from scrap increases. As the amount of internal scrap has decreased considerably, the steel plants recycle more and more collected obsolete and capital scrap. This source of iron has increased rapidly and will continue to increase. In spite of that, some plants may have to include in their EAF charge prereduced iron coming from countries where natural gas is available at low cost.

A better control of the scrap basket charging operation by measuring the real scrap density, a direct visualization device viewing inside the furnace to follow-up the melting progress, an assessment of the liquid bath height by means of a gas blown through a porous brick: three original techniques providing to the furnace operators new tools allowing an optimization of the working practice are described.

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.

The efficiency of automatic flatness control systems in hot rolling mills is based mainly on the capability of the installed instrumentation to provide accurate flatness measurements, on accurate prediction models, and on the selection of an optimum control concept. BFI, together with Thyssen Krupp Stahl, has recently developed a new topometric flatness measurement device (called TopPlan) and advanced flatness control strategies (providing time delay compensation, systematic analysis of shape errors and exact distribution of shape coefficients to be controlled by actuator sets) that offer advantages over conventional techniques and lead to significant improvements in hot rolling processes and strip shape. The present article aims to demonstrate the principles and advantages of these technologies.

The generation of ultrasound by pulsed laser and the detection of these waves by interferometry, shortly called laser ultrasonics, presents many advantages for steel applications because it permits the transduction of ultrasonic waves at a significant distance. Nowadays, this technology is well established in the aeronautical field and is beginning to be used in metallurgy and in the steel industry. This paper describes the physical principles and the technological features of laser ultrasonics. Different examples of present and future applications in the steel industry are presented. They concern different fields, the most important are the monitoring of microstructure in real-time and at high temperature and the on-line measurement of thickness.

The paper presents the work done to assess the usefulness of the thermographic analysis in the design of a detection system for longitudinal defects in coils manufactured by a tandem cold mill. The approach started with a first phase devoted to the development of a computer system for the acquisition of high resolution thermal maps of the whole strip. In the second phase the thermal maps are classified and related to the process variables.

In the context of an ever increasing demand for best surface quality of cold rolled strip, the efficiency of visual inspection is becoming more and more important. VOEST-ALPINE Mechatronics has already developed several combined systems based on automatic inspection followed by the inspection by a human inspector. Such systems are operated successfully on different lines at voestalpine Stahl. In this paper, the design features and the operation mode of these systems are described.

Since about 10 years, Usinor has been extensively developing and implementing automatic surface inspection systems (designated as ASIS). Research work enhanced by industrial developments in partnership with Matra, has produced systems capable of detecting and classifying defects according to the expectations of the users. The data obtained are transformed by a computer-aided post-treatment into automatic grading of coil quality and into guidelines to the operator for the evaluation of its compliance with specifications.

In this paper, two techniques allowing in-line control of the surface cleanliness of steel sheets are presented. Surface pollution is produced during cold rolling and temper rolling. It consists roughly of oil and iron fines. The residual iron content can be measured by a first system based on infrared light reflection. The second system developed for the determination of oil pollution is based on an UV photoemission technique.

Improvements of hot-dip galvanized products in metallurgy, coating quality and surface characteristics have led to coated products usable for automotive outer panels. With adaptation of processing parameters, if necessary, galvanized products give excellent results in forming, assembling and painting, as well as for functional properties (paint appearance and adhesion, corrosion resistance). This is particularly the case for ExtragalR, which is a pure zinc hot-dip galvanized product (GI).