Structure and Phase Transformations in High Nitrogen and High Interstitial Steels of Different Alloying Systems - Short Review

Abstract

The features of the structure evolution under thermal effect of Cr, Cr-Ni, Cr-Ni-Mn, and Cr-Mn-austenitic stainless steels with high nitrogen content and a total high content of carbon and nitrogen are analyzed. When studying the structure, we used light and electron microscopy, X-ray diffraction, dilatometry analysis and electrical resistance measurements. Fine structure and aging processes of austenite, nature and morphology of excess phases, as well as character of phase transformations and their relationship with the properties of steels have been studied. It is shown that Cr-Mn-steels with a high content of (C + N), having a homogeneous structure of austenite without excess phases, surpass Cr-Ni austenitic steels in mechanical and corrosion properties, have higher process ability than Cr-Mn-N-steel and are comparable with them in mechanical properties.