Abstract
This study presents the results of an investigation into the impact resistance of martensitic steel containing retained austenite, produced through quenching and tempering.The aim of the research was to assess the steel's resistance under the impact of projectiles of various calibers.Tests were conducted using the Prototypa ballistic testing system with 5.45×39 mm and 7.62×54R mm ammunition equipped with steel-core bullets.Firing was performed from a distance of 10 meters.The test specimens were 8 mm thick steel plates characterized by a tensile strength of 1462 MPa, Brinell hardness of 454 HB, and impact toughness of 33 J.The bullets struck the plates at velocities ranging from 844 to 877 m/s, with impact energies between 1363 and 3473 J.The results demonstrate that the microstructure formed through thermal treatment provides high hardness and strength while enabling efficient absorption of impact energy.Particular attention was given to the role of retained martensite and austenite, whose presence was found to positively influence resistance to external loads.The findings confirm the high efficiency of the selected heat treatment regime and highlight the potential of the studied steel for use in armor protection systems.