Recent developments
Refining of stainless steels

Since the early 2000s, we have witnessed a twofold evolution. This mainly concerns the K-OBM-S and AOD processes.

The AOD converter is now equipped with a three-nozzle oxygen blowing lance, and its capacity has been increased to 150-160 tonnes. Under these conditions, a steel mill equipped with such a refining tool is capable of producing just over one million tonnes of slabs per year .

This technological evolution has been accompanied by the use of less expensive raw materials. These include chromite (Cr₂O₃), which can partially replace the chromium filler of high-carbon ferrochrome (HC-FeCr) for common grades (Fe-Cr and Fe-Cr-Ni), and molybdenum trioxide MoO₃ for grades with 2% Mo and higher.

As for the K-OBM-S converter (associated, upstream, with two converters, one of which is "recycling"), it also enables the use of dephosphorized liquid...