Malfunction and failure analysis investigations of C26000 (Cu-30% Zn) brass cartridge cases

Abstract

The C26000 alloy, containing 70% Cu and 30% Zn, is predominately used for cartridge case production and has an outstanding record of service. A multiple-step manufacturing process is employed to produce different microstructures in different sections of the cartridge case. The constant demands to increase performance have resulted in frequent revisions to the manufacturing process, and more stringent controls have been implemented in an attempt to produce a better product. Not surprisingly, however, failures and malfunctions are encountered in the “tryout” experiments. Studies indicate that failures in the head section can usually be traced to factors associated with gun design and propellent materials. Failures in the wall section are primarily stress-induced. Descriptions are given of the distinctive modes of failure in various sections of the cartridge case. The causes of failure and the remedies to prevent their recurrence are discussed.