Regulating the dissolution of brittle nano-precipitated phase in FeCrAl alloy by pulse current to repair aging properties

Abstract

Usually, heat treatment is required to elevate the entire material to a higher energy state, thereby eliminating harmful precipitates and repairing the mechanical properties of aged materials. However, the energy utilization rate of this high-temperature treatment method is low, and the regulation of precipitates dissolution is overly dependent on temperature. In this study, an efficient and energy-saving pulse current method was used to control the brittle Cr-rich α′ phase dissolution in aged Fe-25Cr-5Al grade alloy (Fe-24.32Cr-5.67Al-0.043C in wt.%). Compared with conventional heat treatment, pulse current treatment significantly reduces the dissolution temperature and activation energy of the precipitate, and as the current density increases, the non-thermal effect promoting brittle phase dissolution becomes more pronounced. This study is of great significance for the microstructure control and performance design of materials using pulsed current.