HIGH BALLISTIC STRENGTH MARTENSITIC ARMOUR STEEL ALLOY

摘要

The invention relates to an air hardenable high-hardness steel for armouring applications, such as armour plate for use in light armoured vehicles and body armour, and having a high level of ballistic performance relative to its plate thickness. In particular, the invention concerns a high ballistic strength martensitic armour steel which, in an air cooled and untempered condition, has a strength coefficient (s0) of higher than 2500 MPa; a flow parameter (P) of higher than 8.0, preferably higher than 18.0; and a manganese content of 1.8 to 3.6 % by weight of manganese, preferably 2.8 to 3.1 % by weight of manganese. The armour steel also includes retained austenite at a volume fraction of at least 1 %, and preferably a volume fraction of 4 to 20 %.