High strength galvanized bolt is galvanized, so what are their advantages?
Hot dip galvanizing is also used to prevent corrosion on the surface of screw, bolt and nut. High strength galvanized bolt has better corrosion resistance than galvanized screw, but the cost is higher, and high strength structure is not suitable for hot dip galvanizing. Because the coating surface is easy to form hard and brittle, it may break at high temperature or high load.
The durability of galvanized layer of high strength galvanized bolts in corrosive environment is linearly related to its thickness, that is, the thicker the coating is, the longer its life is, but its corrosion resistance is poor in industrial zones containing sulphides. At the same time, a large number of self-coloured corrosive products will be produced in marine and tropical climate. Chromate treatment must be applied to prevent them. In the United States, a thin galvanized sheet with a thickness of 0.03mm was tested. The results showed that the average life of the galvanized sheet was about 3:2:1 in rural areas, coastal areas and industrial areas, indicating that the galvanized sheet was most susceptible to corrosion in polluted air, because there were many sulfur oxides (SOx) and nitrogen and oxygen in the waste gas discharged from factories in industrial areas. Chemical compounds (NO x) can destroy the galvanized layer. A large number of salt crystals and liquid particulates (chlorides) in the atmosphere can cause metal corrosion in coastal areas, and the relative humidity of the atmosphere also significantly affects the corrosion rate. The Institute of Material Protection of Beijing University of Science and Technology has also conducted atmospheric exposure corrosion tests on galvanized coatings in different regions of the mainland for one year. The results show that the highest corrosion rate is found in the areas with the highest SO2 and chloride (sea salt particles) content and the highest relative humidity in the atmosphere. Atmospheric relative humidity is considered to be the main cause of corrosion, and atmospheric pollutants, especially SO2 and chloride, are the main factors to promote corrosion.
Galvanized Heavy Hex Bolt A325M detail information: Material: Stainless Steel: SS201, SS303, SS304, SS316, SS410, SS420 Carbon Steel: 4.8, 6.8, 8.8, 10.9, 12.9 Titanium: GR1-GR5, Aluminum, Brass,etc. Size: M1.6-M39 Length: Up to 300mm Head Type: Flat, JIS pan, Oval, Round, Binding, I.HD, Brazier, PF. HD, Button, Fillister, Ansi.Pan, Pan washer,Indented Hex etc. Standard: ISO,GB, DIN, […]
High Strength Hex Head Bolts, High Strength Hex Head Bolt Nut ASTM A325 Hex Flange Bolt Material:Carbon Steel Certificate: ISO9001:2008,SGS,RoHS Grade: 4.8/8.8/10.9/12.9 Finish:Black Oxide/Zinc Plated/HDG/Dacromet/Nickel Plated Thread: Coarse, Fine Used: Building Industry Machinery Certification: ISO, ROHS, SGS Available Standard: DIN, ANSI, ASTM, JIS, BSW Strength: Grade 4.8, Grade 8.8, Grade10.9, Grade12.9 A2-70, A4-70, A4-80 Finishing: […]