关键词: 接地网, 土壤腐蚀, 腐蚀与防护, 铝铜合金

Abstract: Since Zinc is amphoteric and cannot resist corrosive attack at high pH values, the galvanized steels may suffer corrosion in alkaline soils. A novel aluminum alloy(Al-Cu alloy) with 4.5% mass copper and trace rare earth element is designed to substitute the galvanized steels in high pH value circumstance. The test results show that the corrosion resistances of aluminum alloy is 2.4 times of the galvanized steels. A 450 day’s in-service grounding resistance test has been carried out and the results show that Al-Cu alloy has lower grounding resistance than pure copper. Furthermore, according to the criteria of IEEE Std 837-2002, the sequential tests, which include the current-temperature cycling test, mechanical tests, freeze-thaw tests, salt spray (fog) test and fault-current tests, confirm that Al-Cu alloy can satisfy all requirements and standards of grounding material. Instead of the galvanized steel, the Al-Cu alloy is therefore expected to enhance the service time and reliability as the grounding material.

Key words: grounding grid, soil corrosion, corrosion and protection, aluminum-copper alloy