Silicon effect on the phase composition of nickel base alloys

Phase transformation processes in three EhI929, EhP220, EhP109 nickel base complexly alloyed alloys with silicon additions have been studied using the method of physicochemical phase analysis. The nature and number of phases being formed in the temperature range from 800 to 900 deg C with silicon content from 0.2 to 2.0 % in mass have been determined. It is shown that silicon accelerates the precjpjtation of carbide phases and enters into their composition. eta-carbide of M6C type with a smaller period of lattice than in alloys without silicon, eta-carbide of M12C type and Laves intermetallide phase are formed in alloys with silicon. The silicon effect degree on alloy phase composition is determined by its general alloyage