Failure Analysis of the Strain Clamp Steel Anchor Corrosion of a 500 kV Transmission Line

Abstract

By macroscopic observation, composition analysis, mechanical properties test, SEM, energy spectrum, overall grip tensile test and finite element mechanics calculation method, the strain clamp steel anchor corrosion failure of a 500 kV transmission line is analysed. The results show that the corrosion of steel anchor for 31 years are the result of the natural corrosion, steel anchor corrosion rate is accelerated due to the galvanic corrosion, crevice corrosion, stress and damaged surface of the galvanized layer, and achieve C4 environment (zinc 2.1–4.2 um per year, carbon steel 50–80 um per year). The hardware are qualified. It is suggested to replace the steel anchor with yellow rust on the surface after 5 years, and to reevaluate the next maintenance cycle of the gold fittings without yellow rust on the surface at present, and replace it when the corrosion depth reaches 10%. Before replacement, all fittings should be monitored, especially steel anchor.

Design and research of high strength suspension clamp for transmission lines with large span

“…The suspension clamp of the transmission line is used to fix the wire on the insulator string or hang the lightning rod on the linear pole tower, and it is also used to support the transposing wire on the transposing pole tower, and fix the jumper on the tensioning and corner pole tower, which plays an important role in the transmission line [1][2] .In order to meet the demand of power supply, it is inevitable to construct transmission lines with large intervals under the circumstance of strict type restriction. At present, the materials of overhang line clips serving in the 220kV transmission lines in our country are generally cast iron [3] .…”