Patent ID: 8545993

Claim:
Composite material with a ballistic protective effect having a first, outer layer made of a first steel alloy and a second layer which is directly attached to the first layer and is made of a second steel alloy, and a third layer which is directly attached to the second layer and is made of a third steel alloy, wherein the composite material is manufactured by roll cladding, wherein the first steel alloy of the first layer has the following alloy constituents in per cent by weight (% by weight): 0.06%≦C≦1.05%, 0.05%≦Si≦1.65%, 0.3%≦Mn≦2.65%, 0.015% ≦Al ≦1.55%, Cr≦1.2%, Ti≦0.13%, Mo≦0.7%, Nb≦0.1%, B≦0.005%, P≦0.08%, S≦0.01%, Ni≦4.0%, V≦0.5% and the remainder being Fe and inevitable impurities, the second steel alloy of the second layer has the following alloy constituents in % by weight: C≦0.4%, Si ≦0.8%, 0.05 ≦Mn ≦1.5%, Al≦10.0%, Cr≦1.5%, Ti≦0.5%, Nb≦0.05%, B≦0.005%, V≦0.5%, Mo≦0.6%, P≦0.1%, S≦0.03%, N≦0.3%, Ni≦1.5%, Cu≦3.0%, optionally Sn≦0.04% and the remainder being Fe and inevitable impurities, the second layer having higher elongation than the first layer and wherein the composition of the third layer is the same that of the first steel alloy layer.