Study of Processes of Decomposition of Saturated Solid Solution of Austenitic Steel

Abstract

Recently, in mechanical engineering, particularly in rocket and aircraft building, there has been an increasing use of austenitic steels of the "fermanal" Fe-Mn-Al system, which do not contain relatively deficit components such as chromium and nickel. These alloys have also become of significant interest to the defense and automotive industries because they can maintain high strength and ductility, as well as contribute to weight reduction in structural applications. Additionally, these materials are suitable for producing powders used in additive manufacturing [1]. The stability of austenite over a wide temperature range is achieved by adding up to 30% manganese and up to 10% aluminum. These steels are characterized by high impact toughness, strength, and the ability to harden during deformation. Research [2] has shown that these alloys exhibit high plasticity in combination with increased strength with an increase in manganese content, indicating good technological properties in terms of machinability. The necessary high level of strength characteristics is achieved through the precipitation of second-phase particles during heat treatment [3]. However, the processes of decomposition of the saturated solid solution in these steels are not sufficiently studied, and the known heat treatment regimes do not fully realize the high potential laid down by the developers of these materials.

In light of the above, an important task is to determine the dependence of the mechanical properties of such nickel-free austenitic steels on temperature and duration of isothermal aging. Developing recommendations based on the study of strengthening mechanisms will undoubtedly have practical significance regarding the designation of heat treatment regimes.