Electrochemical Noise of Corrosion of X80 Pipeline Steel in Xinzhou Soil Environment

The electrochemical noise of X80 pipeline steel in Xinzhou soil with different water content was tested by electrochemical workstation,and noise figure and frequency domain were analyzed according to tested noise data.The results show that water content had great effect on the corrosion of X80 pipeline steel in Xinzhou soil.Pitting dominated the corrosion process in Xinzhou soil with low (14%) and middle (18%) water content;uniform corrosion dominated the corrosion process in Xinzhou soil with high water content (22%).The duration of noise fluctuation in electrochemical noise spectra shortened when the water content increased from 14% to 22%.The slope of high-frequency linear segment in the potential PSD (power spectrum density) was large,which changed a lot compared with that in the beginning of corrosion,when uniform corrosion happened in the X80 pipeline steel.And the high-frequency white noise appeared.The slope of high-frequency linear segment in the potential PSD was small,which had little change compared with that in the beginning of corrosion,when pitting happened in the X80 pipeline steel.