MICROSTRUCTURE OF STEEL FRAGMENTS PRODUCED BY EXPLOSIVE CHARGES

摘要

Studies have been made of the fragmentation of steel pipe bombs, as well as of pipe bombs containing pre-formed fragments, including car body sheet and ball bearings. Microhardness measurements showed that the hardness of all the fragments increased, with the greatest increases seen when high detonation pressure explosives were used. Twinning was seen in the pipe bomb fragments only when RDX-based explosives were used. However, twinning was not seen in the preformed fragments, due to either the previously cold-worked state of the car body fragments or to the lower level of explosive confinement. Both macroscopic deformation and fragmentation of the pre-formed fragments were seen, whilst spalling was seen in a microscopic, as well as a macroscopic scale. It is believed that these results will be useful for the forensic scientist who is asked to investigate debris from an improvised explosive device.