Galvanized Steel Pole and Lattice Tower Corrosion Assessment and Corrosion Mitigation

摘要

The principal corrosion mechanisms for galvanized steel electric power utility transmission and distribution (T&D) structures (poles, lattice towers and anchor rods) are presented in this paper. Several important factors often associated with corrosion of galvanized utility structures are deficiencies in corrosion control, coating, soil corrosivity conditions, stray current corrosion, lack of cathodic protection, and copper grounding at the site or at substations. These factors are of primary consideration when accelerated corrosion attack occurs. If identified early on, potential failures can often be prevented. This paper also addresses: (1) Soil Corrosion and Forecasting Soil Corrosivity, (2) Inspection Techniques with Associated Confidence Level Ratings, and (3), Corrosion Mitigation and Cathodic Protection (CP). As part of this paper, a case history of a utility that implemented an innovative system wide CP program after discovering corrosion on embedded poles. To determine the root cause of corrosion a failure, a failure analysis was performed. This paper combines four past publications as well as presents new information and strategies for corrosion prevention for electric power utility T&D structures.