Corrosion of Cannon 75/27, model 1911. Déport, from the Collection of the Military Museum in Belgrade

This paper analyzes the state of the French Cannon 75/27 model 1911. Deport made of steel. The amount of non-corroded materials, the presence of cracks and other defects in the cannon were determined by the radiographic method. The composition of corrosion products were analyzed using diffraction of X-rays (XRD method). In addition to goethite α-FeO(OH), lepidocrocite γ-FeO(OH) and magnetite Fe3O4, the presence of akaganeite was observed in the corrosion products, β-Fe8O8(OH)8Cl1.35 which indicates the accelerated corrosion of the base metal. With the ion chromatography method, the content of chloride, sulphate and other ions in corrosion products were examined. On the basis of conducted experiments, it can be concluded that it is necessary to treat the cannon in appropriate solutions, as quickly as possible, to remove chloride and sulphate ions.