Investigation on the ballistic performance of a dual phase steel against 7.62 mm AP projectile

Dual phase steels have the potential to reduce the weight of structural components because of the improved mechanical properties obtained from the two phases: soft ferrite and hard martensite. In this study, the ballistic performance of a low carbon and low alloy steel was investigated in intercritically annealed conditions. To do this, intercritical heat treatments at three different temperatures were applied to the steel samples separately to get three groups of samples having various martensite volume fractions. The full annealing treatment was also performed on a fourth steel group sample for comparison with the dual phase samples. The ballistic testing was carried out using a 7.62 mm armor piercing (AP) projectile. The experimental results pointed out that the ballistic resistance of the dual phase steel increased by increasing martensite content. In addition, deformed shear bands and/or highly distorted microstructures were observed in all samples irrespective of heat treatment after the ballistic testing. Furthermore, there was a remarkable increase in the micro and macro hardness of the investigated steel samples due to the ballistic induced strain.