Category: marine industry products
Zinc anode floating body
Zinc anodes are used to protect the hull of vessels in fresh and salt water. Common zinc anode standards include...
Marine industry products
Zinc anode floating body
Bernagdas MMO anodes consist of two parts: base metal and coating.
Zinc anodes are used to protect the hull of vessels in fresh and salt water. Common zinc anode standards include ASTM-B 418, BS 7361, DNV-RP-B401, IPS-M-TP-750, NORSOK M-503, and MIL-A-18001K.
According to the NACE-RP0387 standard, the insert used in zinc anodes must be made of galvanized steel.
According to the BS 7361 standard, the zinc anode open circuit potential is about -1.05 V compared to the silver/silver chloride reference electrode, its electrochemical capacity is at least 780 A.h/kg and its consumption rate is at most 11.25 kg/A.year. The efficiency of zinc anodes is also about 90% (the zinc anode electrochemical test recipe and related calculations are mentioned in the DNV-RP-B401 standard).
The relative potential between zinc and iron depends on temperature. At temperatures higher than ambient temperature, the potential difference between iron and zinc decreases. In some waters, at temperatures above 50 degrees Celsius, the polarity between iron and zinc is reversed. That is, zinc has become more cathodic than iron in terms of potential, and not only is it not able to protect iron in the form of sacrifice, but it also causes its faster corrosion. Therefore, zinc should not be used to protect iron in water environments with temperatures higher than 60 degrees Celsius.
