Estimation of the Effectiveness of the Galvanic Couple Cu-Zn with Respect to the Naked Zinc
Authors: Sanchez Bello ANA PATRICIA 
Published: February 2020

In this work, the effectiveness of the Cu-Zn galactic in terms of bare zinc is evaluated by using the electrochemical techniques addressed the problem. Why is galvanizing convenient? How feasible is galvanizing that speaks in economic costs? The environmental impact that is had when galvanizing it? taking into account that this type of materials are widely used in the industries of the automotive, construction and national parastatal CFE, CONAGUA, PEMEX.

In the state of Veracruz there are factors such as humidity that is on average 75-80 percent, aggravating the presence of corrosion in an industrial marine geographical environment chlorides present in coastal areas by proximity to the Gulf of Mexico, sulfates suspended in the air and sulfur present in the combustion process. Making use of a potential and the electrochemical cell creating a controlled system in which we allow ourselves to see what happens with the variables of study pH, concentration and time. The constant generation of iron is evident from the foregoing that when using some metal it is synonymous with corrosion.

Zinc is a metal with a cubic crystalline structure centered on the faces providing great resistance to mechanical deformations, excellent conductor of heat and electricity.

The electrolyte used for the study is NaCl, being potentially corrosive, functioning as an anion, zinc being the cation, causing the metal to self-corrosion.

The tendency of Zinc to a quasi-static state is observed as the days go by having segmentations of thermodynamic and kinetic equilibrium the variation of potential respect in hours -0.028 Eew / V compared with the days on average -0.022919 Eew / V formed in the metallic substrate films that control the corrosive process presented adsorption of 〖OH〗 ^ - present in bubbles on the electrolyte when the variable time increases the amount of electrolyte occupied by 〖OH〗 ^ -. The formation of hydroxides the incorporation of a longer exposure time increased the depreciable voltage of 1%, for the current intensity the average variation of -0.140 / A was reflected while the days passed decreased on average of -0.128 l / mA.

the galvanized shows a linear in quasi equilibrium due to stabilizers that are used to give better mechanical properties to the alloy such as Bismuth, Nickel, Indian and Aluminum discarding the hypothesis that its velocity of Ecorr is equal to that of pure zinc, the galvanized maintains its equilibrium quasi static in function of the time superior in 3% to the one of the zinc being more effective the galvanized against the corrosion having an Ecorr of -0.9956 Eew / (V) smaller that the one of the zinc that in average is -0.94036 Eew / (V) the barrier type that creates the zinc when alloying when galvanizing copper avoiding direct contact with the atmosphere, existing a galvanic protection present in the surface at microscopic level porosity zinc exerts its cathodic power forming protective oxide films covering the porosities of the material the 〖CO〗 ^ 2 found in the atmosphere is incorporated to the surface of the substrate reacting with the electrolyte having carbonated products the sulfur presents oxidation reactions in the environment presented "islands" or blisters with different corrosion products another influential is the pH resulting from corrosion products having alkalinity providing protection by neutralizing the corrosive agents.