Influence of heat treatment on phase and structure formation and magnetic properties of soft magnetic alloy 80NKhS manufactured by additive technology

The evolution of the structure and phase composition of the soft magnetic alloy 80NKhS, produced by selective laser melting and annealed at different temperatures, was studied by light and electron microscopy, X-ray spectral and X-ray structural analyses. It has been established that a weakening of structural anisotropy and an increase in the average grain size occurs only at temperatures of 1250°C, associated with the oxides of Al, Ti, Si, Mn, Cr and nickel silicide previously formed during additive alloying. These phases have high thermal stability and inhibit grain growth, limiting the magnetic permeability of the alloy. To achieve the required level of magnetic properties, the soft magnetic alloy 80NKhS, manufactured by the additive method, must be annealed at higher temperatures than specified in GOST 10160–75.