Libostorage tank aluminium alloy sacrificial anode Anti-corrosion material

Most metal equipment in seawater or the cathodic protection of the interior floor of a crude oil storage tank cannot be used in a soil environment with low chloride content. The electrode potential of the aluminum sacrificial anode is -1.05 volts, and the capacitance of the aluminum sacrificial anode decreases with the increase of temperature when the ambient temperature is higher than 49 degrees Celsius, which can be referred to the formula: Z=2500-27 (T-20), the working temperature of the T anode, unit ° C. In saltwater environments, the current capacity of aluminum sacrificial anodes may be reduced by half. Aluminum sacrificial anodes can be fixed directly to the structure of the equipment to be protected without the need for other substances as fillers

Pure aluminum cannot be used as a sacrificial anode material because the passivation film potential on its surface is more positive. By adding an alloy to prevent the formation of this oxide film, the activity of the aluminum anode can be maintained. Aluminum anode alloy contains zinc, cadmium, indium, mercury, tin and so on. Zinc acts as the initial activation of the aluminum anode, and other alloys maintain the long-term activity of the aluminum anode. Some formulations add manganese, silicon, and titanium to balance the activity and self-corrosion. Both iron and copper have adverse effects on the current capacity and potential of aluminum anode. Adding a small amount of silicon (0.11%) can eliminate the adverse effects of iron. Aluminum anodes require chloride ions for activation. When the chloride ion content is lower than the chloride ion content in sea water (3.5% sea water, chloride ion content 35000mg/L), the capacitance of aluminum anodes will decrease and the potential will become positive. When the chloride ion content is lower than 4200mg/L, the aluminum anodes will become positive. The aluminum anode potential reaches -1060mV (CSE), a barely acceptable potential, and the capacitance is significantly reduced. The capacitance of aluminum anode decreases with the decrease of current output density.

Aluminum anode performance is affected by the chemical composition of the alloy, we provide different alloy composition to meet customer requirements, we can also manufacture special specifications of the chemical composition of the anode according to customer requirements.