Aiming at serious corrosion of GIS aluminum alloy housings during operation in recent years

the authors analyze two typical corrosion accidents at different positions of two GIS aluminum alloy housings. It is found that the electrochemical corrosion due to the circular current generated on bus’ s aluminum housing and the accumulated water at corrosion position（i.e. inductive potential）is the mail cause of the accidents. The rate and degree of corrosion depends on the circulation current density at corrosion defect. The authors describe the conditions and principle of generating electrochemical corrosion of the aluminum alloy housing

prove that AC electrochemical corrosion of GIS aluminum alloy housing will occur during operation in certain conditions

and provide some countermeasures against the corrosion.