Calculated phase equilibria for the CrFeNiSi system— I Ternary equilibria

Abstract

A set of thermodynamic data for the calculation of phase equilibria for the OrPeNi rich portion of the CrFeNiSi system over the temperature range 650 to 1000 K has been provided. The equilibria are required to aid the interpretation of the structural behaviour of 18/8-type stainless steel fuel-cladding alloys during neutron irradiation. Themodynamic and phase diagram data for the stable phases in the CrSi, FeSi and NiSi systems have been critically assessed, and data for the unstable sigma phases in these and the CrNi and FeNi systems estimated. Provisional values for the lattice stabilities of the sigma form of the elements Cr, Fe, Ni and Si have also been provided. Isothermal sections for the CrFeNi system and the low silicon portions of the CrFeSi, CrNiSi and FeNiSi systems have been calculated for the temperature range 700 to 1173 K, and experimental phase diagram data for these systems critically assessed.