Heat Treatment Effect on Multicomponent Nickel Alloys Structure

Superalloys are widely used in many industrial applications that require operating at elevated temperatures and pressures, applied static and dynamic stresses and aggressive environment due to their extraordinary mechanical properties and surface stability. Nickel-based superalloys have a face-centered cubic lattice, high values of Young' s modulus and coefficient of diffusion that provide to Nickel-based superalloys excellent physical and mechanical properties. In this paper is analyzed Nickel-based superalloy Hastelloy S. Mechanisms of strengthening are discussed as a function of chemical composition and vacuum heat treatments. Applied microscopic investigations were following the process of superalloy Hastelloy S structural degradation, with the main concern to observe the problem of cracking formation in material as well as structure ameliorisation after thermal processing in vacuum. The diffusion -interfacial mathematical model using Cahn-Hilliard equation that satisfactorily describes coarsening and phase-segregation kinetics is analysed in this paper.