INVESTIGATION OF THE EFFECT OF THERMOPLASTIC DEFORMATION ON THE MICROSTRUCTURE OF THE ХН56МВКЮ ALLOY

This review examines the mechanisms through which thermoplastic deformation can influence the microstructure of the ХН56МВКЮ alloy, with particular emphasis on the general behaviour of nickel-based heat-resistant alloys. The discussion focuses on the effects of deformation temperature, strain rate, and accumulated strain on work hardening, dynamic recovery, dynamic recrystallisation, grain-boundary evolution, and the stability of strengthening phases. The Zener–Hollomon parameter is introduced as a framework for describing the combined effects of temperature and strain rate. Published studies indicate that the response to hot working is alloy-specific; therefore, the deformation behaviour of one nickel-based superalloy cannot be quantitatively extrapolated to another without verifying its composition, initial microstructure, and processing history. An issue concerning alloy nomenclature is also identified: the designation ХН56МВКЮ provided for this manuscript could not be confirmed in the standard reference consulted, whereas a closely resembling grade, ХН56ВМКЮ (ЭП109), is listed in historical alloy-grade data. Consequently, composition-specific statements and numerical processing windows are not assigned to ХН56МВКЮ in the absence of a material certificate. The review provides a theoretical foundation for planning material-specific hot-compression tests and metallographic assessments.