Strengthening and control of second-phase particle precipitation in ferritic/austenitic/martensitic heat-resistant alloys: a review

Heat-resistant alloys with excellent mechanical properties are widely used in various fields, and further improvement in their properties is essential to meet the requirements in new-generation advanced supercritical boilers, nuclear reactors, superheaters, and other new materials applications. To effectively enhance the comprehensive performance of heat-resistant alloys, second-phase particle strengthening has been widely studied, and in the face of different service environments of advanced heat-resistant steels, the selection of suitable second-phase particles is essential to maximize the performance of these alloys. To this end, three major types of reinforcing phases in heat-resistant alloys such as carbides, rare earth oxides, and intermetallic compounds are summarized. A comparative analysis of the precipitation behavior of the reinforcing phases with different types as well as the risks and means of controlling their use in service, is presented. Key parameters for the application of various types of second-phase particles in heat-resistant alloys are provided to support the design and preparation of new ultrahigh-performance heat-resistant alloys.