Process for the production of alloyed or unalloyed steels with a low content of non-metallic oxide inclusions

摘要

A process for the production of alloyed or unalloyed steel with a low content of non-metallic inclusions comprises adding a deoxidizing agent other than aluminium and then adding to the molten metal, at a temperature at least 150 DEG C. above the liquidus temperature, an amount of aluminium sufficient to give in the solidified metal an aluminium content of 0.5% to 0.50%. The deoxidizing agent may be Mn or Si and the Al may be added in liquid form to the metal at a temperature 180 DEG C. to 200 DEG C. above the liquidus, preferably during tapping. The Al content of the steel may be seven times the nitrogen content. It is stated that heat treatment of the metal does not produce any grain growth.