Effect of tempering time on the ballistic performance of a high strength armour steel

The investigation describes and analyses the effect of tempering time on the mechanical and ballistic performance of a high strength armour steel. The steel is subjected to tempering at 300 °C for 2, 24 and 48 h. A marginal variation in strength and hardness is observed with increase in tempering time, whereas ductility and Charpy impact values are found to be decreasing. Ballistic performance of the samples are evaluated by impacting 7.62 mm and 12.7 mm armour piercing projectiles at 0° angle of impact. Results show a small variation in the ballistic performance when impacted with 7.62 mm armour piercing projectile. A decrease in ballistic performance of the material is observed with increasing tempering time when impacted with 12.7 mm armour piercing ammunition.