Galvanizing is the process of adding zinc coating on the surface of steel or iron. Because zinc is used as a sacrifice coating, it protects the steel or iron below, so it can extend the service life of metal components.
But galvanizing is a complex process that can be performed in various ways. There are different forms of galvanizing, including heat -soaking galvanized and hot diffusion galvanized, these changes have their own advantages and disadvantages. Therefore, before incorporating it into the prototype design or manufacturing project, it is helpful to understand different forms of galvanizing.
Galvanized metal is more common than you think. The structures such as building frames, metal benches, balconies, ladders, and firearms can be made of galvanized metals to ensure longer service life and sufficient corrosion and damage protection. Other examples can be found in car parts and electrical appliances.
In addition, galvanized steel and galvanized iron can be used for different manufacturing processes, from sheet metal processing to CNC processing, making it the main process of manufacturing.
Galvanized
The two most popular forms of galvanizing are hot -dip galvanized and electroplating. Let's discuss these two methods and other methods. Knowing which type of galvanizing may require the help of experts.
1) Hot gongoring
During the heat -soaking galvanized process, the metal was immersed in a hot zinc bath of about 450 ° C. When it is removed, the coating surface and oxygen reaction form zinc oxide, and then react with carbon dioxide to form zinc carbonate. Before galvanizing, clean the metal with a harsh alkali solution must be used, and then pickled in an acidic solution; zinc chloride can also be used to prevent metals from premature oxidation before galvanizing.
2) Electro -galvanized
Dalvation is galvanized with electroplating: the current through zinc bath with zinc anode and steel conductor. The coating produced by this process is thinner than hot -dip galvanized, and it also produces brighter surface smoothness suitable for cosmetics applications.
3) osmotic zinc
There are several names in this form of galvanizing: hot diffusion galvanized, steam galvanized and dry method galvanizing. It involves heating the steel parts to 500 ° C in a closed rotation drum containing zinc powder. The evaporative zinc spreads to the surface of the steel parts to form a firm binding coating. It is very suitable for small parts and parts that need to be coated inside.
4) Galvanized
Galvanizing is a combination of hot drops and annealing. The hot -dip galvanized process is carried out normally, before the coating metal is used to remove any extra zinc through the air knife. Then heated the metal at 500–565 ° C medium, so that the iron and zinc layers spread each other and form zinc iron alloy layers.
Advantages of galvanized
Prevent corrosion substances: zinc coating on galvanized metals prevent corrosive substances from reaching the weaker underlying substrate metal. This can extend the service life of the substrate, especially in the required application.
Prevent rust: A significant delayed rust of galvanizing.
Create sacrifice anode: zinc coating is consumed by corrosive substances, so it provides protection for the following metal until it is completely used. Even if the scratches penetrate the coating, zinc will be used up before the iron.
Durable: Zinc coating formed by galvanized zinc coating is tough and long -lasting, usually providing for decades of protection for the underlying metal.
Affordable: Galvanizing is a very simple and affordable program, providing significant benefits with the least expenditure.
Forming thick coating: Although it is not suitable for all applications, galvanized coating will produce thicker coating than electroplating.
