Failure Analysis on Cracking of Cartridge Case

Lots of cracks were found on H68 brass cartridge cases. By means of macro and micro observation, energy spectrum analysis, metallographic examination and residual stress measurement, the cracking cause was analyzed. The results showed that the cracking mode of the cartridge case was stress corrosion cracking. The stress corrosion cracking generated at the mouth of the cartridge case because of the residual tensile stress, large grain size and the corrosion medium.