Hot-dip galvanizing, also called hot-dip galvanizing, […]
Hot-dip galvanizing, also called hot-dip galvanizing, is a method in which steels components are immersed in molten zinc to obtain a metal coating. The following describes the protective performance of the hot-dip galvanized hexagon flange bolt.
Hot-dip galvanizing usually has a thickness of 5-15μm, while the hot-dip galvanizing layer is generally above 35μm, even as high as 200μm. Hot-dip galvanizing has good coverage, dense coating, and no organic inclusions.
The anti-atmospheric corrosion mechanism of zinc includes mechanical protection and electrochemical protection. Under atmospheric corrosion conditions, there are protective films of ZnO, Zn(OH)2, and basic zinc carbonate on the surface of the zinc layer to slow down the corrosion of zinc to a certain extent. This protective film (Also known as white rust) is damaged and a new film is formed. When the zinc layer is seriously damaged and the iron matrix is endangered, zinc will produce electrochemical protection to the matrix. The standard potential for zinc is -0.76V, and the standard potential for iron is -0.44V. When zinc and iron form a microbattery, zinc is dissolved as an anode. Protected as a cathode. Hot-dip galvanizing has better atmospheric corrosion resistance to base metal iron than electro-galvanizing.