Types of seamless steel pipe corrosion

Corrosion in the form of seamless pipe buried pipe is divided into local corrosion and uniform corrosion of the two, local corrosion dominance, the greatest danger. The pipeline is mainly electrochemically dissolved during soil erosion, which causes corrosion of the pipe perforations due to the formation of corrosive cells. Corrosion by the size of the anode and cathode cell gap, but also the formation of corrosive cell corrosion of steel into micro-cells and macro-cell corrosion of two categories. The so-called micro-cell corrosion, refers to the role of a few millimeters from the micro-cells in the pipeline, or even just separated by a few microns of the anode and cathode caused by corrosion. Its shape is very uniform, also known as uniform corrosion. Since the distance between the microanode and the cathode is very close, the rate of corrosion of the micro-cell does not depend on the resistivity of the soil but only on the micro-processes of the anode and cathode electrodes. Buried steel pipe micro-corrosion.


The so-called macro-cell corrosion, refers to the galvanic action, refers to the pipeline by a few centimeters far or even a few meters of corrosion caused by the anode and cathode areas. Macro battery corrosion, also known as local corrosion. The corrosion rate of macro cells is related to the soil resistivity except for the anode and cathode electrode processes, since the anode and cathode zones occupy a substantial proportion of the total resistance of the corrosion cell circuit. Large cell erosion rates reduce soil resistivity. This is due to large cell erosion in buried pipelines or plaque-like corrosion on the surface, which can be quite damaging.