INTERACTION BETWEEN REFRACTORY MATERIAL A ND STEEL, AND ITS EFFECT ONTHE PURITY OF THE STEEL .2. NITROGEN, HYDROGEN AND CARBON CONTENT, AND THE EFFECT OF FLUSHING

The development of metallurgical process technology within the domains of secondary metallurgy and casting today makes it possible to produc e highly pure steels containing ultralow concentrations of nitrogen, h ydrogen and carbon. In order to ensure such low concentrations, there must be no influence exerted by way of the refractory material. The mo lten steel must be protected against contact with the atmosphere to av oid any nitrogen pickup. The sources of hydrogen and carbon in the ref ractory material must be kept as few as possible to minimize any hydro gen and carbon pickup. Efficient and reliable stirring systems are add itionally required so as to accelerate the metal-slag reactions that t ake place.