Research On Crossion Behavior Of Equipment Materials In Modified Flue Gas Condensate

At present,the technology of desulphurization from flue gas has been widespread applied.The corrosion of desulphurization equipment is quite serious because of the complex composition in flue gas,such as Sulfur dioxide,carbon dioxide and hydrogen chloride.The vast majority of desulphurization equipment in our country is imported from abroad,so it is necessary to conduct a study of the corrosion for this equipment.The corrosion of flue gas is related with Specific fuel and desulphurization technology.In accordance with the conditions provided by an oil field,this article conduct a research on corrosion of stainless steel and glass flake coating for flue gas desulphurization equipment,and provide some reference value.In this paper,the breakdown potential of pitting and Crevice corrosion for 304 and 2205 stainless steel was investigated by Potentiodynamic polarization curve in modified green death solution.It was found that the corrosion of 304 stainless steel was very sensitive with increase of the temperature.When the temperature reached 60℃,the breakdown potential of the pitting is -0.15V and the breakdown potential of crevice corrosion is -0.25V,so it was prone to pitting and crevice corrosion and can't be suitable to equipment of flue gas.But the 2205 stainless steel had good corrosion resistance,when the temperature reached 60℃,the breakdown potential of the pitting was 0.90V and the breakdown potential of crevice corrosion was 0.70V.Not only having good resistance to pitting corrosion,but also having good resistance to crevice corrosion.It can be used as materials for desulphurization tower installation.At the same time,the long-term corrosion behavior of 304 and 2205 stainless steel immersed in modified green death solution was investigated by EIS.The results showed that the corrosion resistance of 304 stainless steel was reduced with growth of soaking time, but 2205 stainless steel was able to maintain a good corrosion resistance.In this paper,the water permeability of glass flake coating in modified desulphurization solution was appraised by Zero-gravity test.It was found that the rate of water permeability was 5.19%in modified desulphurization solution at 60℃,which exhibited good resistance to permeation.Electrochemical Impedance Spectroscopy(EIS) was applied to investigate the corrosion behavior of glass flake coating in the condition of different temperature and time. The results showed that,the corrosion resistance of glass flake coating decreased with increasing of the temperature immersion time.And calculating the water permeability was 7.19%by Capacitance change,it was basically the same as 5.19%derived from weight-loss method.Finally,this paper analyzed the corrosion step of glass flake coating with increasing of the soak period.