Effect of strength and ductility on anti-penetration performance of low-carbon alloy steel against blunt-nosed cylindrical projectiles

As a traditional protective material, steel has been developing towards higher strength and better ductility. The dynamic mechanical behavior, ballistic resistance, together with the deformation and fracture modes of steels vary with the characteristics of strength and ductility. In this study, three kinds of low-carbon alloy steel including Q235A, 10CrNiMo and 22SiMnTi, which have great differences in strength and ductility, were selected as research objectives. To compare the anti-penetration performance of these steel plates subjected to the ultra-high strength blunt-nosed cylindrical projectiles, the perforation tests were conducted with the impact velocity of 750±5 m/s in both. The analysis of pre and post-impact microstructure indicates that with the densest lath martensite structure, the highest strength steel 22SiMnTi forms adiabatic shearing fracture as the stress exceeds the shear strength; with better ductility, Q235A and 10CrNiMo are characterized by more compact post-impact microstructures and obvious plastic flow. Consistent with above analysis, the validation tests showed that 10CrNiMo exhibited the best resistance to blunt-nosed cylindrical projectiles, and followed by 22SiMnTi and Q235A. The excellent anti-penetration performance of low-carbon alloy steel is due to the integrated optimization of strength and ductility.