Are stainless steel pipelines buried in need of corrosion protection?
In the aqueous medium such as Cl-, the localized destruction of the passive film due to acidification of the dielectric solution in the crevice (increasing of Cl- concentration, decrease in pH value) and hypoxia (oxygen concentration cell, gap hypoxia). The most fundamental is to eliminate the gap from the structure is designed to avoid the gap of the heat exchanger tube is connected with the gap at the gap on the tube plate, flange, gaskets, bolts, rivets, to take appropriate measures to prevent.
Pipeline buried environment factors: underground laying requirements of 3, one is corrosion protection, two is elevation, slope, and three is density. If it is electrochemical reaction, the design should have technical instructions or preventive measures.
The factors of the material itself: stainless steel pipe structure exists because of the equipment, or the existence of cracks of metal or non-metal deposits on the surface, in the sediment and the stainless steel tube surface in the formation of cracks, corrosion, will give priority to produce punctate and ulcer like damage in the crevice, which is crevice corrosion.
