Research on the Erosion of Gun Barrel Based on Vented Vessel Tests

The vented vessel test, as an alternation of the firing practice, is implemented to reconstruct the deterioration process of the gun barrel suffering the thermochemical erosion by propellant combustion gas. High pressure of over 300 MPa with a duration exceeding 20 ms is applied on the rifled specimen. A phase transition layer about 136 mu m is observed by scanning electron microscopy (SEM) from the cross section of the test specimen. Some residual oxidation products of the iron can be detected by energy dispersive x-ray spectroscopy (EDS) on parts of the inner surface. A comprehensive erosion analysis is conducted, which estimates that the mass loss of the specimen is mainly attributed to the periodical formation and peeling of the chemical reaction layer on the bore surface. The most severely eroded part is located on the corner of the land. On the basis of the examined erosion mechanisms, a proper thermochemical erosion model is employed. The mass dissipation and the geometry evolution under continuous firing are simulated using finite element method (FEM). The simulation phenomenon shows good consistency with results of the experimental tests.