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Hot galvanizing, also known as hot-dip galvanizing and hot-dip galvanizing, is an effective method of metal corrosion protection, mainly used for metal structures and facilities in various industries. It is a process technology to obtain coating by immersing steel, stainless steel, cast iron and other metals into molten liquid metal or alloy. It is a widely used steel surface treatment method with better performance and price in the world today. Hot-dip galvanized products play an inestimable and irreplaceable role in reducing corrosion and prolonging life, saving energy and materials of steel. At the same time, coated steel is also a short-term product with high added value supported and prioritized by the state.
Production process
The production and processing of galvanized steel coil can be divided into three major steps: first, the whole coil of strip steel shall be pickled for rust removal and decontamination to make the surface of galvanized steel strip bright and clean; After pickling, it shall be cleaned in ammonium chloride or zinc chloride aqueous solution or ammonium chloride and zinc chloride mixed aqueous solution, and then sent into the hot dip bath for galvanizing process; After the galvanizing process is completed, it can be warehoused and packaged.

Development history of hot galvanizing
Hot galvanizing was invented in the middle of the 18th century. It was developed from the hot tin plating process and has entered the fourth century. Up to now, hot-dip galvanizing is still a more widely used and effective process measure in steel corrosion prevention.
In 1742, Dr. Marouin carried out a pioneering experiment on hot-dip galvanizing of steel and read it at the Royal College of France.
In 1837, Sorier of France applied for a patent for hot-dip galvanizing and put forward the idea of using galvanic cell method to protect steel, that is, the process of galvanizing and rust prevention on iron surface. In the same year, Crawford of the United Kingdom applied for a patent for zinc plating using ammonium chloride as solvent. This method has been followed up to now after many improvements.
In 1931, Sengimir, a particularly outstanding engineer in the modern metallurgical industry, built the world’s first continuous hot-dip galvanizing production line for strip steel by hydrogen reduction method in Poland. The method was patented in the United States and the industrial hot-dip galvanizing production line named after Sengimir was built in the United States and Maubuge Iron and Steel Plant in France in 1936-1937, respectively, creating a new era of continuous, high-speed and high-quality hot-dip galvanizing for strip steel.
In the 1950s and 1960s, the United States, Japan, Britain, Germany, France, Canada and other countries successively produced aluminized steel plates.
In the early 1970s, Bethlehem Iron and Steel Company invented the Al-Zn-Si coating material with the trade name Galvalume, which has a corrosion resistance of 2-6 times that of pure zinc coating.
In the 1980s, hot dip zinc-nickel alloy was rapidly popularized in Europe, America and Australia, and its process was named Technigalva At present, Zn-Ni-Si-Bi has been developed on this basis, which can significantly inhibit the Sandelin reaction during hot plating of silicon-containing steel.
In the 1990s, Japan Nisin Steel Co., Ltd. developed a zinc-aluminium-magnesium coating material with the trade name of ZAM, whose corrosion resistance is 18 times that of the traditional zinc coating, which is called the fourth generation of high corrosion resistant coating material.

Product features
·It has better corrosion resistance and long service life than ordinary cold rolled sheet;
·Good adhesion and weldability;
·A variety of surfaces are available: large flake, small flake, no flake;
·Various surface treatments can be used for passivation, oiling, finishing, environmental protection, etc;
Product use
Hot dip galvanized products are widely used in many fields. Their advantages are that they have a long anti-corrosion life and can adapt to a wide range of environments. They have always been a popular anti-corrosion treatment method. It is widely used in power tower, communication tower, railway, highway protection, street lamp pole, marine components, building steel structure components, substation auxiliary facilities, light industry, etc.