Research On Soil Corrosion And Protection Of Pipeline

The corrosion of pipeline in soil is closely related with each physical and chemical nature in the soil. There are many corrosion influencing factors. Sometimes soil corrosion factors play a role alone, sometimes various factors play a role together. Selecting the appropriate evaluation method is determined by soil corrosion evaluation.On the basis of the corrosion evaluation on the Pipeline from Sichuan to East , seven factors are taken into account to set up a mathematical model for evaluating corrosion of the pipline. The factors in soil include water content, salt content (including Cl-,SO42-,HCO3-), electronic resistivity, pH value, soil oxidation-reduction potential. There are various of testing methods to study X70 steel's corrosion rate in the soil. The most important testing method is electrochemical method and weight loss. Different components of soil determine the impact of corrosion by testing. The Tafel curves measurement and linear polarization is the most fundamental way.The evaluation model is established based on Grey theory,Fuzzy mathematics and BP artificial neural net work,and the example is showed. Especially, according to the soil corrosion data,using BP artificial neural net work and MATLAB Neural Network Toolbox,models for prediction of corrosion rate of pipeline steel in soil are designed to describe the relationship between corrosion rate and soil factors. From the simulation results, forecast and the actual difference between the value of error is very small. Using BP artificial neural net work, sample data can get effective learning, simulation and prediction, particularly for soil corrosion, which involves a number of factors into account the complexity of the process, the neural network can show its superiority. Based on the academic study, the corrosion Evaluationn Software which is only suitable for the Project from Sichuan to East has been developed. This software can be an assistant decision-making tool for the evaluationn for corrosion of Project from Sichuan to East.