Detection And Study On The Atmospheric Of Substation Equipment And Transmission Line

The substation equipment and transmission line exposed in polluted air environment, are vulnerable to erosion of corrosive ion in atmospheric environment. In this paper, we choose four substation in GuiZhou Power Grid, Establish a corrosion monitoring site, monitoring the main corrosive pollutants in the atmosphere, and atmospheric exposure testing in the natural environment are carried out. At the same time, simulated accelerated corrosion tests are doing in the laboratory. Research on atmospheric corrosion mechanism of metal, provides reference for power grid substation of metal material corrosion control.Based on the meteorological and corrosive pollutants monitoring statistics found that the sulfate deposition amount in this 4 monitoring sites is higher, and humid and rainy climate. The mean annual depositing amount of sulfate are 43.83mg/(m2?d), 36.72mg/(m2?d), 31.22mg/(m2?d) and 38.16mg/(m2?d), respectively. A, B and D in P2 corrosion level, C in the P1 level. 4 monitoring sites affected by chloride contamination are smaller, pollution level in S1 level, close to S0.By the weightlessness analysis of samples installed in sites, the corrosion rate of 6 kinds of materials from high to low in turn for Q345>Q235>galvanized steel>copper T2>brass H62> Al 6101, the corrosion rate are about 37?m/a, 35?m /a, 2?m /a, 1.6?m /a, 1.0?m /a and 0.38?m /a. surface appearances show that: the rust layers of Q345 are loosen, the thickness is larger than 100?m. SEM analysis of the surface of metal corrosion morphology. XRD analysis show that the corrosion products of Q345 and Q235 mainly consist of: FeOOH, Fe2O3, Fe3O4. The corrosion products of T2 mainly consist of: CuSO4 and CuO. The corrosion products of H62 consist of: Zn(OH)2, Zn SO4, ZnS, ZnO, CuO, Cu SO4. The corrosion products on the surface of Al 6101 are mainly Al2O3, Al(OH)3, and any crystal particle. The corrosion products on the surface of galvanized steel are mainly Zn(OH)2, Zn SO4, and any crystal.By electrochemical impedance spectrum and polarization curve analysis found that in the laboratory to simulate the accelerated corrosion test, Q345, Q235, copper T2 and aluminum alloy 6101 electrodes with the increase of electrode surface SO2 deposition amount, the impedance value decreases, and the corrosion current density increases, when SO2 deposition quantity on the surface of Brass H62 SO2 and zinc is small, the corrosion is not serious, corrosion resistance value increases, the corrosion current density decreases, and when SO2 deposition amount continues to increase, the impedance value decreases, and the corrosion current density increased. And Cl- on 6 kinds of materials are with strong corrosion, with Cl- pollutant deposition quantity increases on the surface of electrodes, the electrode impedance value decreases, the corrosion current density increases.The SEM analysis show that: SO2 pollution and Cl- pollutants on Q235 and Q345 has very strong corrosion damage, serious corrosion of carbon steel surface. SO2 pollution and Cl- pollutant deposition in the brass H62 electrode surface will appear loose corrosion products. Cl- deposition on the surface of copper T2, surface oxidation film suffered severe damage, Corrosion intension. Through SVET study the corrosion behavior of metals under a thin liquid film found: Q345, T2, H62 and Al 6101 with the extension of experimental time, the anode zone area is expanding on the surface, ion current is added, ion current is increased, the corrosion speed up; Q235 and zinc electrode with the extension of time, the anode zone area is expanding, ion current value decreased.