The adding nitrogen processes by added nitrided ferrochrome (56. 2%Cr
7. 33% N) with (0. 1 ~0. 6) x 10
5
Pa argon or nitrogen atmosphere in 200 kg vacuum induction furnace for melting nitrogenous stainless steel Crl3 (0. 04% ~0.06%N)
Cr23Nil9 (0. 22% 〜0.28%N) and Cr22Ni9 (0. 15% ~0. 19%N) have been tested and studied. Results showed that with added nitride alloy in nitrogen atmosphere the yield of nitrogen was more than 80%
while with added nitride alloy in argon atmosphere the yield of nitrogen only 10%. With increasing nitrogen pressure in furnace
controlling suitable adding temperature and adding smaller size nitride ferrochrome