Study For The Corrosion And Cathodic Polarization Behavior Of 16Mn Steel In Soil

In this paper, different types of soil are chosen for laboratory tests. Electrochemical testing, in combination with the analysis of the physical and chemical character of soil, are used to study the soil corrosion and the cathodic polarization behavior of 16Mn steel in the different soil with several humidity. As a result, the rule of selecting cathodic protection potential is discussed in soil.Studies show: the moisture content is the prominent factor, which influence the corrosion behavior. As the moisture content change, the corrosivity comes to a critical value, namely at the middle humidity the soil corrosivity becomes the strongest. The effects of pH are show only in the middle and high humidity. With humidity increasing, the corrosivity of the acid soil increases correspondingly. At the same time, the humidity also is the important factor that influences the hydrogen involvement reaction. In the middle and high humidity, the hydrogen involvement reaction becomes very easy.According to EIS measurement the Rt-Ee,c curves are drawn to analyze the control mechanism of corrosion and select the cathodic protection parameter. By the studies of effect of the hydrogen involvement to coating degradation, the suggestions are put forward in selecting the voltage of the cathodic protection.