MARTENSITIC TRANSFORMATIONS IN STAINLESS STEELS

Currently, the direction of materials' research, in which the martensitic transformations are observed, is intensively developed. This is due to the fact that, in the martensitic-transformation process, various defects of crystal structure (twins, dislocations, packaging defects, etc.) are formed in many materials, which together with grain fragmentation lead to a significant increase in the strength properties. The widespread occurrence of martensitic transformations has led to the study of the defective microstructure features and changes in the mechanical properties in the martensitic transformation process. This allowed the theory of martensitic transformations to occupy a key place in the science of the structure and properties of crystalline bodies. The operating temperature range of steels of this class is limited from below by their tendency to low-temperature embrittlement (cold breaking) under radiation effects, and from above, by the level of long-term strength (heat resistance). In this regard, today, the increased attention of specialists in the field of condensed matter physics to ferritic-martensitic steels is caused by the need to identify the mechanisms for the formation of microstructures and functional properties of steels stable at operating temperatures, as well as to search for reserves to increase their heat resistance, while maintaining a sufficient plasticity level.