EFFECT OF ALLOYING ELEMENTS ON THE FORMATION OF LAVES PHASE, SIGMA-PHASE, AND R-PHASE IN MULTICOMPONENT BCC FE-BASED ALLOYS .1. EXPERIMENT

The experimental and calculation method fbr the determination of the m echanism of the effects of alloying elements on aging in the bcc Fe-ba sed Cr-Mo-Co-Ni-W and Cr-Mo-Co-Ni alloys with the formation of multico mponent (Me(A), Me(i))(m) (Fe, Me(i))(n) intermetallic compounds is pr oposed. The method combines a physicochemical analysis of the determin ation of the amounts and compositions of phases and the calculation of the thermodynamic activity of a Me(A) element forming the phase and o f the excessive Gibbs energy of binary compounds. The intermetallic ph ases with tetrahedral close-packed lattices are the subject of the stu dy. The dependences of the minimal Me(A) concentrations necessary for the formation of binary Laves phases on the enthalpy of their formatio n. are constructed for the estimation of the effects of Me(A) elements on the Gibbs energy of the formation of multicomponent intermetallic compounds.