Metal Melting and Casting Technology :
The steel for the hot-rolled sheet is produced according to the blowing Metallurgy; process in basic oxygen steel plants with converter capacities of 260 t and 380 t. In the course of the refining cycle, argon is additionally injected through the converter bottom, thereby creating the precondition for keeping within very tight target analysis limits without over refining the heat. A good level of steel cleanness is achieved.
Vacuum treatment and additional ladle metallurgy measures make it possible to produce steels with extremely low carbon levels (< 0.003 00). These steels form the basis for special deep-drawing qualities, including IF (Interstitial Free) steels in which carbon and nitrogen are no longer dissolved as elements in the steel matrix, but are fixed by means trolled and fully automated.