Perforation of an ultra-high strength steel penetrated by shaped charge jet

The “white” etching layer on the perforation surface and adiabatic shear bands (ASBs) in the matrix of ultra-high strength steel plates penetrated by shaped charge jets were investigated. It is shown that the phase transformation took place in the “white” etching layer on the perforation surface during penetration. The microstructure of the “white” etching layer is a mixture of martensite and austenite, both of nanometer scale. The ASBs in the matrix are composed of local shear deformation zones (LSDZs) and heat affect zones (HAZs). No evidence of phase transformation was found in the HAZs of ASBs. The temperature rise on the perforation surface and within ASBs was estimated.