Recycled steel accounts for 46% of the iron resource of the steel industry in the world and has generated a new production route, based on the electric arc furnace, that produces 33% of the world steel output. Recycling is fully integrated in the market economy and has gained experience and technologies that allow 75% of the steel of end of life products to be effectively recycled. Furthermore, allowing for a modicum of cautions, this recycling is sustainable, which means that it may be repeated indefinitely, a feature that can be claimed by few materials. The use of scrap to produce steel requires 75% less energy than the integrated production route, that means 92% less energy than what is required to produce the same amount of aluminium. The electric arc furnace also allows the recycling of zinc, which is easily separated from the galvanized steel sheets used in construction and automotive industry. A large project federating the contributions of industry and academia, led by USINOR, has been carried out from 1995 to 2000 to support the sustainable recycling of steel: the main results of the “Iron Cycle” are reported in this paper.

Nippon Steel Corporation started the operation of a dust recycling plant based on technologies of the rotary hearth furnace. The Kimitsu plant has a large 180,000 ton-per-year capacity. New technologies of pellet making, zinc recovery, iron oxide reduction, DRI pellet sintering, etc. are developed and adopted. The dust and sludge are reduced and transformed in almost zinc-free DRI pellets that are strong enough for the BF charge. This plant has solved the problem of the increase in zinc load of the BF when charging dust and sludge.

Shredder residue is an unavoidable by-product of the treatment of end of life vehicles and household appliances. NKK has developed a new post-treatment process in which the residue is introduced in a bath of solvent made of hot tar and gives an overflow of plastics and metallic sediments. The recovered plastics can be injected into the blast furnace and the metallic parts recycled in the steel shop. This new process allows a high recycling rate of treated materials.

This article reviews the major aspects of the historical success of the LD process developed in Austria exactly fifty years ago. At the start there are the fundamental considerations of Henry Bessemer and their successful transposition into an industrial steelmaking process. The evolution led to several modern variants of the process, which account presently for a significant part of the world steel production.

Starting from known linear models for calculating the electric energy required to elaborate a heat in an electric arc furnace, new approaches based on artificial neural networks (ANN), have been studied. The effects of strongly non-linear relations between critical furnace process parameters, and other variables, not taken into account in an equation based model, have been integrated in the ANN models. Both the off-line and on-line use of models based on time series and a new system of interconnected ANNs are described. The on-line model is designed to accurately predict the end of the heat.

Two different approaches are available to reduce the mass of automotive steel wheels. The traditional approach is based on the use of high resistance steels that allows a thickness reduction of the rim and disc. A mass reduction up to 25 % can thus be obtained. A different approach allows a larger mass reduction with a more drastic change in the wheel production technology. One possibility is to use laser welded blanks to feed the existing manufacturing lines. Another possibility is to implement a combined spinning and rolling of the rim. These new steel solutions allow a mass reduction up to 50 %. Indeed they allow adjusting precisely the steel thickness and properties to the local service conditions. Finite elements calculations have been carried out to assess the static and dynamic behaviour of the new wheels.

This new process of die necking for beverage cans consists in exploiting advantageously two properties of metal: the thickening during the shrinking and principally the decrease of the flow stress during the process, improving the metal formability. The increasing die necking process rates harmonize the diameter reduction of the consecutive stages with the aptitude of the can wall to be shrunk. This new kind of necking route with increasing rates makes possible to limit the number of stages especially to neck thinner cans, and to make the dies more tolerant towards the imperfections of the cans.

All over Europe, multi-storey car parks represent an increasing market for steel construction. In France, fire safety regulation imposed structural stability requirements, which diminished dramatically the competitiveness of steel solutions. During the last 5 years, CTICM and other European partners have demonstrated the remarkable behaviour of composite steel and concrete structures under natural fire conditions. As a consequence, and with the authorities approval, a first steel frame open car park has been erected late 2000 near Paris.

The properties of the well known enhanced steel 12 Cr Mo9-10 are compared with those of the most recent generation of modified CrMoV steels who are characterized by the addition of vanadium. The comparison concerns the base material properties before and after heat treatment, as well as the influence of hot forming and welding with and without step cooling. Creep data are also reported.