Abstract In this study, the ballistic response of high-hardness ARMOX 600T armor steel under repeated impacts of 0.3 caliber Fragment Simulating Projectiles (FSP) was numerically investigated. ARMOX 600T, with a Brinell hardness of approximately 600 HB, is widely used in heavy armor applications due to its excellent combination of hardness and impact resistance. It is particularly preferred in armored vehicle structures and fixed protection systems where high levels of ballistic protection are required. Numerical simulations were conducted using the ABAQUS/Explicit finite element software, and the material behavior was defined using the Johnson–Cook strength and damage model. Three successive impacts were applied to the same location of 5 mm thick ARMOX 600T plates at velocities of 500 m/s, 750 m/s, and 1000 m/s. The study comprehensively examined the deformation geometries and stress distributions of both the projectile and the armor plate. The results revealed that projectile velocity and the number of impacts play a critical role in maintaining the structural integrity of high-hardness steel armors subjected to repeated ballistic loads. In this context, the findings provide valuable insights for armor designers and researchers evaluating ballistic performance under multiple-hit scenarios.