Resistance to corrosion is one of the main indicators of durability and reliability of any fasteners. Its influence on the metal takes place according to the scheme, Like in the electrochemical cell. otherwise talk, low alloy potential zone undergo complete destruction, and area, having a high potential, successfully maintain their own structure.
To resist corrosion, use a large number of ways. for example, materials, resistant to it or special metallic coating. Still, impose additional metal coating, film, resistant to oxidation. Use another type of sacrificial protection.
To protect Fasteners, selected three main methods.
- Oxidation involves coating the surface oxide films. Resources for two hours immersed in baths specially adapted to the presence of a powerful electric heating. To add caustic soda, natrievuyu selitru. The contents were heated to a temperature 130-1400S, and this method does not guarantee high performance anti-corrosion. It is for this reason,, Materials treated with additional mineral oils, proper lubrication. This method is most often, It used to protect fasteners made of ferrous metals, aluminum, magnesium.
- Galvanizing zinc is the coating surface. As, the negative potential of zinc is much higher, than that of iron, the coating is capable of providing excellent anticorrosion characteristics. Electrolytic or electroplating method allows to save on zinc, improve coating properties. Wherein, coating thickness reaches 5-35 m. The product can be of different colors, and it depends on the additives. Luster - is a material property, treated by this method, he adds the aesthetic characteristics of the product.
- Phosphating is used then, when the fasteners need to ensure their high anticorrosive properties, and penalties to the aesthetic appearance absent. Also corrosion resistance, This method helps to give the product insulating; adhesive anti-friction; oil intensive properties. They are achieved due to the fact, iron phosphate that can resist oxidation. The films exhibit different crystal structures – if it is less, the protective properties of the above. Besides the above combination methods of protection applied, advanced treatment options.
