The Nano-Duplex NANOS-BA Steel for Application in Construction of Armours

The paper presents mechanical and physical properties measured in static conditions, and some properties determined in dynamic conditions, of plates of new nano-composite bainite-austenite (NANOS-BA) steel to be used for construction of armours. Firing tests of NANOS-BA steel plates fixed on a base plate of RHA (Rolled Homogenous Armour), Armox 500T and Armox 600T steel, carried out by means of 12.7 mm B-32 projectiles have demonstrated that in the conditions of tests, NANOS-BA steel shows better protective properties than 500BHN and 600BHN – grade commercial plates. NANOS-BA steel plate of minimum 5 mm thickness has protected Armox 500T and Armox 600T plate from piercing. Quantitative effects were assessed of firing the NANOS-BA steel plates of 50 x 50 mm and 100 x 100 mm surface dimensions, and thickness in the range of 5÷10 mm, as well as sets of the NANOS-BA steel plates of 100 x 100 x (4÷8) mm dimensions, arranged in layers on the base plate. It was determined that ballistic limit V50 for NANOS-BA plate of 6.0 mm thickness, for the 7.62 x 51 mm M61 AP (Armour Piercing) projectile, amounts to 797±10 m/s. Based on the analysis which compared results of tests carried out with the application of various parameters it was estimated that the value of V50 obtained for NANOS-BA steel is higher than the parameters of the highest grade steel plates offered in the global market. The tests imply that NANOS-BA steel is a prospective material for armour construction which can enable to reduce weight of armours and/or to improve their protective parameters in comparison with the presently used structures. Due to very high protective capability, monolithic plates of NANOS-BA steel can be used as one of the layers of the composite armour.