Buried into the form of thick-walledseamless tubeof uniform corrosion and localized corrosion of corrosion are two more to localized corrosion dominated, is also its greatest danger. Steel corrosion process in the soil is mainly electrochemical dissolution process due to the formation of corrosion cell resulting in pipeline corrosion perforation. By corrosion of the battery anode and cathode area the size of space, but also the thick-walled underground corrosion in the form of thick-walled seamless steel pipe into two kinds of uniform corrosion and localized corrosion, localized corrosion than the main, the greatest danger. Steel pipe corrosion process in the soil is mainly electrochemical dissolution process due to the formation of corrosion cell resulting in pipeline corrosion perforation. By corrosion of the battery anode and cathode area the size of space, but also the form of thick-walled seamless pipe corrosion is divided into micro-and macro-cell corrosion cell corrosion of two categories.
The so-called micro-cell corrosion is only a few millimeters or even refers to a few microns away from the anode and cathode are composed of micro-cell function caused by pipe corrosion. The shape feature is very uniform, it is also known as uniform corrosion. As the micro-anode and cathode micro very close distance, so the micro-cell corrosion rate does not depend on the soil resistivity, only on the micro-micro-anode and cathode electrode process. Micro-cell corrosion of buried thick-walled seamless tube of less harmful.
The so-called macro-cell corrosion, and even a few centimeters apart is a few meters from the anode and cathode area consisting of the role of macro cell corrosion caused by the thick-walled seamless tube. Macro-cell corrosion, also known as localized corrosion. As the anode and cathode areas far away from the soil media, the total loop resistance in the corrosion resistance of the battery in the account for a large proportion, so the speed of the macro-cell corrosion in addition to the anode and cathode electrodes and related to the process, but also with the soil resistivity. Soil resistivity large, macro-cell corrosion can reduce the speed. Thick-walled seamless tube of buried surface of the plaque or cavities form of corrosion that is caused by the macro-cell corrosion, its harm is considerable.
In summary, thick-walled seamless pipe buried in the soil being the major electrochemical corrosion, the corrosion process is divided into anode and cathode process, the current flow three processes, independent of each other and each other, a process which blocked the other two a process is blocked, it will stop and slow down the corrosion cell. This thick-walled seamless tube for corrosion measures we take to provide a theoretical basis.
Post time: Feb-08-2022