Importance of the surface and environmental conditions on the corrosion behavior of brass, steel and brass coated steel wires and brass coated steel cords

•Brass coated steel reactivity is driven by a galvanic coupling between brass and iron.•Steel dissolution rate is controlled by O2 mass transport and its reduction kinetic on the brass surface.•Iron dissolution participates in the local acidification of the solution at the wire surface.•Interfacial pH decrease promotes the corrosion rate of steel in brass coated steel.•Oxidants in aerated sulfate solution (e.g, NO32-) inhibit the copper redeposition and promote brass dissolution. In tires, cords consist of brass coated wires. Even if they are embedded in rubber matrix, wires remain sensitive to corrosion. This work proposes an evaluation of the electrochemical reactivity of the constituents of the wire: the steel, the brass, and the brass coated steel. Tests were immersed in solutions where pH, solution convection, and oxidizing species were controlled. Results confirm the establishment of galvanic coupling between iron and brass. In aerated and neutral solution, the dissolve dioxygen reduction acts on the interfacial pH modifying the reactivity of the brass coated steel.