Study of protective coating on steel wire strands for telecommunications in coastal areas

摘要

Communication lines are usually composed of steel and other metallic components and are built outdoors. To determine whether local corrosion is inhibited in coastal areas, which are tough on metals, we conducted a longterm (23 years) exposure test on Miyake Island. The test candidate was steel suspension wire used for suspending communication cables on telephone poles. For preventing corrosion such wires, Zn coating had been used. However, some steel wire strands located in coastal areas still corroded. This is because air born sea salt particles from the ocean are blown by the wind and adhere to the surface of metals. To protect steel wires against atmospheric corrosion, Al coating was applied because of its higher corrosion resistance compared with that of Zn coating. This coating still did not prevent corrosion at specific points in the coastal areas. We compared three types of steel wire strands, Zn coated and Al coated, which are currently used for protecting steel wires, and one Al coated with sacrificial anode tape was efficient in preventing on steel wires had efficacy as protecting corrosion by conducting the exposure test in Miyake Island for 23 years.