Denitrifying slag for molten ferrous alloy contg. chromium - contains alkali metal carbonate, oxide, and/or hydroxide, together with fluoride and/or chloride, and iron and/or nickel oxide

摘要

Method is described for removing N from a molten Fe alloy contg. 3% Cr without causing oxidn. of Cr in the melt. In the method the carbon content of the alloy is adjusted to 2%, and the melt treated with molten slag which is composed of =1 of alkali metal carbonate, alkali metal oxide or alkali metal hydroxide 1-30 (pref. 3-20)%, together with =1 of alkali earth metal fluoride or alkali earth metal chloride 30-70(pref. 35-60)% and Fe oxide and/or Ni oxide 1-50(pref. 20-40)%. Alkali earth metal oxide and/or alkali earth metal carbonate in an amt. 40% may be further contained in the molten slag at 1500-1850 degrees C. The Fe alloy may be stainless steel etc.