Study On Strong Polarization Of Metal Corrosion Detection Method And Application

Faced with the threat of metal corrosion to human society,metal corrosion testing will be of great significance,especially for metal corrosion detection in complex electromagnetic environments such as grounding nets.Through comparative analysis of domestic and foreign metal corrosion detection technologies,it is found that conventional electrochemical metal corrosion detection techniques are difficult to apply to the complex electromagnetic environment of power systems.Therefore,this paper presents a strong polarization corrosion detection method,which has important theoretical significance for the evaluation of metal corrosion status in strong electromagnetic environment.A conventional corrosion detection system was established for the comparative study of conventional corrosion detection and strong polarization corrosion detection.Based on the theory of cathodic protection,an experimental platform for accelerated corrosion and cathodic protection was established,and two sets of experimental carbon steels were used as working electrodes.The linear polarization method,three-point method and tafel curve extrapolation method were used to calculate the corrosion parameters of the experimental carbon steel,and the three-point method for calculating the corrosion current was optimized to make the calculation result more accurate.Combined with the mass method to verify the corrosion of accelerated corrosion of carbon steel.A strong polarization metal corrosion detection method was proposed,and the time constant was used as a characteristic parameter for evaluating the corrosion status of the species.Since the conventional corrosion detection technology mainly obtains a polarization curve by applying weak perturbation signals to the electrodes,the weak polarization detection technology cannot be applied to actual field corrosion detection with large noise.In this paper,a strong polarization corrosion detection system and a grounding grid detection system are constructed,and a strong polarization corrosion detection method with strong anti-interference capability is studied,and the corrosion detection of a real grounding grid is gradually studied.It was determined that the bipolar excitation signal was used as the excitation source and the non-polarized electrode was used as the reference electrode.By comparing with the unipolar excitation signal,it was found that the bipolar excitation signal is more effective in suppressing potential drift and better anti-jamming capability,and has an advantage in data processing.In the aspect of the choice of reference electrode,through the comparative study of the experiment,selecting the non-polarized electrode as the reference electrode can better suppress the potential drift and obtain a more accurate attenuation curve.The influence of different lengths of metal on the strong polarization attenuation curve was studied and analyzed.The research on experimental data processing and feasibility verification of metal corrosion evaluation with time constant ? of strong polarization attenuation curve were completed.Through the processing of the data falling edge,data interval selection,fitting algorithm comparing,complete the processing of the experimental data to obtain the attenuation coefficient ?.Through long-term experimental accumulation,the attenuation coefficient changes with time,which reflects the relationship between the strong polarization attenuation curve ? and the degree of corrosion of the grounding grid.That is,as the degree of corrosion deepens,the time constant ? will gradually decrease.And combined with theoretical analysis to verify the feasibility of this new detection method.