Knowledge

3 posts

Schlacke_ist_das Werkzeug_der_Stahlerzeugung

Slag – a tool for steel production

Slag is the tool of steel production. The lighter slag floats on the melt and can absorb and bind unwanted elements from the steel. By that, you can increase the so-called degree of purity of the steel. After the work being done the slag has different colorings (depending on the elements absorbed) and is nothing more than artificially produced rock.

Chemische_Zusammensetzung_Stahl_Rost

The wondrous world of chemistry

Depending on its chemical composition, steel changes its properties very strongly. If it contains more than 12% chromium, it is coated with a chromium oxide layer only a few atoms thick, which protects it from corrosion. An example of such stainless steel is cutlery. By immersing stainless steel in saline solutions, the salt eats wholes into the protective layer. This can happen, for example, when too much salt is used in the dishwasher.

Recycling_Stahl_Elektrolichtbogenofen

Electric arc furnace, steel and recycling

As of today, the most efficient way to recycle steel is the electric arc furnace (EAF). The steel is produced by passing high currents through huge graphite electrodes into the scrap. Between two of our graphite electrodes flows about as much current as through 200,000 light bulbs.