Preparation Technology of 45steel/60Si2CrA Multilayer Composite Armor Plate

Modern composite armor plate is generally composed of faceplate with high hardness and backplate with good toughness. 45 steel/60Si2CrA multilayer composite casting blank with 11 layers, containing 60Si2CrA steel as faceplate and 45 steel as backplate, was fabricated by composite casting. The deformation and heat treatment process of 45steel/60Si2CrA multilayer composite plate were studied. The results show that the interfaces between faceplate and backplate have good combination and the thickness of each layer is basic uniform by reasonable deformation distribution. Yield and tensile strength of the composite plate reaches 956MPa and 1018MPa, the hardness of 45 steel layer and 60Si2CrA layer is 448HV and 536HV respectively after the heat treatment of 860°C water quenching+ high temperature tempering. The mechanical properties meet the qualification of armor plate. The bulletproof test displays that 45 steel/60Si2CrA multilayer composite armor plate can prevent the breakthrough of DAP51B type bullet with the velocity of 500m/s.