This is done when microorganisms deteriorate and non-metallic materials. It 'a process that occurs at the interface and is determined by concentrations of O, sali, pH, redox and conductivity. All these parameters can be affected by microorganisms growing interface and mainly affect carbon steels.
The bacteria produce acids HNO3 – H2SO4 – H2SO4 that attack the metal. In addition to Cu, Zn and Ag have fungicidal properties, antifouling and antibacterial, but Ag and Zn have a low toxicity with respect to Cu.
The corrosion occurs only if the Zn coating, obtained by hot dip galvanizing, It is compromised by pitting (vaiolatura), thing that happens in the case of pipes for the transport of H2THE, oils and gases with thicknesses of Zn < 50 µm.
La zincatura a spruzzo, especially in the sector of the pipes for drinking water transportation, with thicknesses > 50 uM and covered with sealant, It does not present these problems because the Zn thickness can be elevated above the 50 uM and then the pores are filled by low viscosity sealants that isolate the Zn.
The 20% Corrosion occurs because of the microbes and microorganisms attacks, species on pipes for the transport of H2THE, oil and gas.