The denitrogenation technology and mechanism of a new kind of Ni-base superalloy during vacuum induction melting (VIM) were studied. The nitrogen content could be reduced from 0.0005% to 0.0002% by this technology. The calculated interaction coefficient of Ti with N () is about -0.38, and the activity coefficient of N () is 0.714. The denitrogenation mechanism was discussed through the calculation of the reaction ratio constants and .

By adding FeNCr6-A, K417G alloys with different nitrogen content from 4 to 32ppm were prepared by using the vacuum induction melting (VIM). The precipitation of the carbonitrides in the virgin alloys was studied. The results show that N mainly exists in Ti (N, C) phase which sometimes served as heterogeneous cores for the carbides in the alloy. Besides, a few isolated regular square blocky Ti (N,C) particles were also found in alloy with 10ppm N, and these isolated particles became larger in the alloy with 21ppm N. Moreover, as N level reaching 32ppm, the Ti (N,C) phase did not grown but these particles usually gathered together and formed many clusters. For the alloy with 4ppm N, the content of N in Ti (N,C) was lower, but for the alloys not less than 10ppm N, the N content of Ti (N,C) was higher and relatively stable.