Corrosion-electrochemical behavior of zinc alloy ZnAlCuPb4-1-2.5 doped with sodium in an electrolyte environment NaCl

Zinc metal grade Ts3 is not widely used. Due to the fact that it contains up to 2.0 – 2.5 % lead. We were given the task of synthesizing a new alloy based on tHe ZnAlCu4-1 zinc alloy using substandard Ts3 grade zinc and additional alloying with metallic soda. Hence the abbreviation of the ZnAlCu4-1 alloy was changed to ZnAlCuPb4-1-2.5. This paper presents the results of a study of the effect of sodium addition on the corrosion-electrochemical behavior of the zinc alloy ZnAlCuPb4-1-2.5 in a NaCl electrolyte environment. The study was carried out on a pulse potentiostat PI-50-1.1 using the potentiostatic method at a potential sweep rate of 2 mV/s. It has been shown that alloying the ZnAlCuPb4-1-2.5 alloy with sodium shifts the potentials of free corrosion, pitting and repassivation to the positive region. With increasing concentration of chloride ion in the NaCl electrolyte, the corrosion rate of alloys increases, regardless of their composition. The addition of sodium to the ZnAlCuPb4-1-2.5 alloy reduces its corrosion rate by 10 – 15 %. Improving the corrosion resistance of zinc alloy ZnAlCuPb4-1-2.5 by 10 % allows the thickness of the protective coating on the protected products to be thinned by the same amount with the same service life. At the same time, for 10,000 tons of zinc costing $4,000 US spent for the above purposes, a 10 % saving is equal to 1,000 tons. The economic effect in this case is 1000·4000=$4 million. USA.