During frequent long-term standby state of gas turbine generator unit

the surface of 08Al carbon steel of waste heat boiler economizer fin tube will have serious corrosion problems. In this paper

the macroscopic corrosion phenomenon and corrosion rate of 08Al carbon steel above the critical humidity were studied by the method of hanging piece and electrical resistance probe. The results show that the corrosion rate of 08Al carbon steel is the fastest in the first 5 days under the constant environment of 20 ℃ and relative humidity of 70%

and the corrosion depth reaches up to 0.85 μm

accounting for 47.7% of the total change in the whole process. However

the most obvious corrosion phenomenon

including the change of weight and the surface corrosion area

occurred from about the 19th to the 25th day. With the relative humidity gradually increasing from the critical humidity of 70%(ambient temperature 20 ℃)

the corrosion evaluation indexes of 08Al carbon steel show a linear upward trend. Nitrogen filling maintenance strategy under long-term standby state was formulated

effectively alleviating the corrosion condition of economizer fin tube of waste heat boiler.