Galvanic corrosion of gun barrel joints in corrosive environments: Experimental and numerical investigation

Galvanic corrosion in firearm barrel assemblies poses a critical durability challenge, particularly at the interface between dissimilar steels forming electrically coupled joints. This study investigates the galvanic behavior of a 30CrMoV barrel tube coupled with a 1050 carbon steel barrel base in chloride (NaCl) and acidic (H2SO4) environments. A combined experimental and numerical approach was employed, including twenty-eight-day immersion tests and a validated finite-element model based on secondary current distribution principles. Electrolyte potential, current density, and corrosion rate distributions were measured experimentally and reproduced numerically to examine the spatial evolution of attack along the joint interface. Results demonstrate that joint geometry is a decisive factor in corrosion severity: increasing contact length amplifies current crowding, elevates the cathode-to-anode area ratio, and accelerates localized dissolution. Simulation and experimental outcomes show close agreement, confirming the predictive capability of the modeling framework. These findings provide mechanistic insight into geometry-dependent galvanic corrosion and deliver actionable engineering guidance for optimizing contact length, managing area ratios, and selecting appropriate materials. The study establishes a validated framework for predicting corrosion behavior and supports design strategies to improve the service life of firearm components and other critical dissimilar-metal assemblies.