Flat steel products from Salzgitter with significantly lower CO2-Footprint thanks to electric steel production
05.05.2021 | Salzgitter Flachstahl GmbH
The continually rising environmental awareness in the markets is resulting in customer demand for steel products with the lowest possible CO2-footprints.
Over the long term, the SALCOS® innovation project will enable Salzgitter Flachstahl (SZFG) to switch its steel production to a climate-friendly production route that is low in CO2 emissions.
In order to meet today’s demands for rolled products with a lower CO2-footprint, work is currently underway to reduce CO2 emissions in steel production by harnessing the resources already available in the Group.
The steelmaking process in place at Peiner Träger GmbH (PTG) in Peine is based on the electric arc furnace process. By comparison with the blast furnace-blast steel mill route traditionally employed in Salzgitter, this has the advantage that the feedstock involved in slab production consists of 100% scrap. In the scrap, the iron is already present in metallic form and does not have to be separated from the bound oxygen in an initial step, as is the case with the ore in the blast furnace. The extraction of oxygen, technically known as reduction, is carried out in the blast furnace by carbon. By opting for the electric arc route, the amount of CO2 involved in slab manufacturing can be reduced to around a quarter compared with the blast furnace route.
In close teamwork between Peiner Träger and Salzgitter Flachstahl, a concept was drawn up in the second half of 2020 for supplying SZFG with Peiner slabs of electric steel, thereby enabling the production of flat steel with a significantly reduced CO2-footprint.
After upgrading the casting equipment for slab production, the first slabs were delivered to Salzgitter as early as November 2020.
The Peiner steel mill is designed for the production of crude steel for long products. Consequently, input materials, as well as melting and casting aggregates are not comparable with those in place at the Salzgitter Flachstahl steelworks. In addition, PTG only has limited production capacity available for slab production for its sister plant in Salzgitter, as the Peiner crude steel is primarily required to supply the beam lines there.
Therefore, PTG can currently only provide a limited quantity of slabs for Salzgitter Flachstahl. With the existing casting equipment, slabs can be produced in thicknesses of 250 mm and in widths of 800 - 1100 mm. This enables the production of hot-rolled strip with widths of 850-1080 mm.
In order to embark on environmentally friendly, low CO2 steel production based on Peiner slabs, a selection of grades was worked out between Peiner Träger and Salzgitter Flachstahl with which a selected segment of flat steel production can already be served. Given the melting metallurgical orientation of PTG's electric steel plant towards long steel products, the complete implementation of Salzgitter Flachstahl's product range is currently not feasible.
Currently, both mild and a number of microalloyed steels are produced from Peiner slabs.
As part of the process and product launch, newly produced PTG grades are inspected in Salzgitter after each production step and only passed on to the next process stage if they pass quality assurance standards.
The first low CO2 footprint products are already being processed at customer locations, and the knowledge gained to date is being used to incrementally expand the portfolio of grades that can be produced by the low CO2 production route outlined here.
