Simulated calculation and analysis on equilibrium precipitated phases MBC6 and ferrite as well as non-equilibrium solidification of martensitic stainless steel 9Cr18Mo ( % : 0. 95 〜1. 10C
16. 6 ~ 18. 0Cr
0. 4 - 0. 7Mo) have been carried out by using Thermo-Calc thermodynamic calculation software. Results show that during solidification the segregation of C
Cr
Mo and Fe in steel 9Cr18Mo is rather serious
the C and Cr content in steel have definite effect on the precipitated amount of M
23
C
6
and the elements such as Cr and Fe content in M
23
C
6
and in matrix
while the change of Mo content in steel only effects on the precipitated amount of M