This is a roll bonded, dual hardness armor plate consisting of a high hardness front side to break up or flatten incoming projectiles while the back side functions to capture the projectile. The composition of both faces is a Ni-Mo-Cr steel, but the front side has a higher carbon content, which leads to a higher hardness after heat treatment. The front and back sides are roll bonded by a multi-step, proprietary process which involves heating the assembly to a specific temperature and hot rolling it until the two sides develop a strong, metallurgical bond. The roll-bonded plates are annealed, sheared, and flattened. A careful and precise heat treatment is required to achieve optimum ballistics performance. Information provided by Allegheny Ludlum. |