| Aluminum Conductor Steel Reinforced （ACSR） is the main conductive materials of highvoltage electricity transmission. It is important for electric power to guarantee thetransportation safely. However, it is easy for ACSR to corrode, as a result of outage andinfluencing the safety of transportation. Therefore, it is important for the safety and durabilityof ACSR to research the corrosion behavior of ACSR.In this paper, Tafel linear extrapolation method, AC impedance technology, salt spraytest and accelerated corrosion test were employed to study the influence of pH andtemperature on the corrosion behavior of ACSR in5%NaCl solution and the simulated acidrain solution. From the experiment, some corrosion parameters were obtained in differentsolutions. Corrosion parameters include corrosion potential, polarization resistance, corrosioncurrent density and corrosion speed. The physical and chemical properties of corrosionproducts are characterized by XRD and SEM. Possible corrosion mechanism is presented.Main conclusions are as follows:①In neutral NaCl solutions, the corrosion potential of ACSR decrease when theconcentration of NaCl increase. While the concentration of NaCl increases from10mg/L to50mg/L, the corrosion speed of ACSR increase by6-8times. If the concentration of NaClincreases to70mg/L, the corrosion speed of ACSR increases to40times of10mg/L rapidly.②EDX shows: before the test of salt spray fog corrosion, Al2O3existents on the surfaceof sample mainly. After1.5months, Zn is detected on the surface that its concentrationincrease with the concentration of Cl-. Electrochemical corrosion occurs between Zn layer andACSR. With the increase of concentration of Cl-, the protection of Zn strengthens. Corrosionproducts include mainly Zn0.64Al0.36（OH）2（CO3）0.18·0.86H2O.③The Electrochemical test of simulated acid rain solution shows: the polarizationresistance of ACSR at pH6.0is3and12times of pH2.0and pH4.0respectively. With thedecrease of pH, radius of capacitive loop decreases and corrosion speed increase also.Corrosion test of simulated acid rain solution shows: the corrosion speed of ACSR at pH2.0is4times of pH4.0. After corrosion test of simulated acid rain solution, the increasing of O isdetected by EDX.④The Electrochemical test of simulated acid rain solution under stress shows: thecorrosion speed of ACSR increase with the increase of stress. When the stress is271N and pHis4.0, the corrosion current density reach3.96×10-3mA·cm-2.But compared with pH=2.0, the corrosion current density change small, which proves that the influence of H+is smaller thanstress in the corrosive process of ACSR.⑤Corrosion mechanism of ACSR: First, Al2O3film dissolve in the solution of Cl-;Second, primary cell are formed between Zn layer and ACSR, as the potential of Zn is higherthan Al, so Zn dissolve firstly and Al is protected from dissolved. Last, if Zn layer dissolvefully, primary cell are formed between Al and Fe of ACSR, as the potential of Al is higherthan Fe, so Al dissolve and Fe is protected from dissolved. |
PDF Full Text Request