Erosion inside a 20 mm gun barrel for pressure up to 5000 bars

The ISL 20-mm-caliber test-gun was used for erosion measurements in cooperation with IFAM, doing surface analytical and metallographical investigations of surface elements (sensors). The determination of superficial steel compositions by Auger Electron Spectroscopy (AES) has proofed that with the german single-base propellant A 5020 surface layers up to a depth of 0.3 Mym were carburized. In this case, erosion is below 0.1 Mym. Firing with the french double-base propellant GB-Pa 125/0.8 resulted in an oxidation of the steel surfaces up to a depth of some Mym. The mass loss of about 1.7 Mym per shot is in the order of the oxide layer thickness. Within five rounds for both propellants there were no indications for the erosion inhibiting action of the TiOsub2-additive. AES depth profiling has revealed that Ti in form of TiOsub2, TiOsubx and/or TiN is embedded in the oxide layer.