Overview
Galvanizing, also known as hot-dip galvanizing or hot-dip galvanizing, is an effective method of metal corrosion prevention, mainly used on metal structural facilities in various industries. It is a process technology that immerses metals such as steel, stainless steel, cast iron, etc. into molten liquid metal or alloy to obtain coatings. It is the most widely used and cost-effective surface treatment method for steel in the world today. Hot dip galvanized products play an immeasurable and irreplaceable role in reducing corrosion, prolonging service life, and saving energy and materials for steel. At the same time, coated steel is also a high value-added short-term product supported and prioritized by the country for development.
History of Development
Hot dip galvanizing was invented in the mid-18th century and developed from the hot-dip tin plating process. It has now entered its fourth century. So far, hot-dip galvanizing is still the most commonly used and effective process measure for steel corrosion prevention.
In 1742, Dr. Maroin conducted groundbreaking experiments on hot-dip galvanizing of steel and presented them at the Royal Academy in France.
In 1837, Sauriel of France applied for a patent for hot-dip galvanizing and proposed the idea of using the galvanic cell method to protect steel, which is the process of galvanizing and rust prevention on iron surfaces. In the same year, Crawford in the UK applied for a patent for galvanizing using ammonium chloride as a solvent, and this method has been continuously improved to this day.
In 1931, the most outstanding engineer in modern metallurgical industry, Polish man Sengemir, built the world's first hydrogen reduction continuous hot-dip galvanizing production line for strip steel in Poland. This method was patented in the United States and industrial hot-dip galvanizing production lines named after Sengemir were built at the Maubeuge steel plant in the United States and France from 1936 to 1937, ushering in a new era of continuous, high-speed, and high-quality hot-dip galvanizing for strip steel.
In the 1950s and 1960s, countries such as the United States, Japan, Britain, Germany, France, and Canada successively produced aluminum plated steel plates.
In the early 1970s, Bethlehem Steel Company invented an aluminum zinc silicon coating material called Galvalume, which has a corrosion resistance 2-6 times that of pure zinc coating.
In the 1980s, hot-dip galvanizing nickel alloy was rapidly promoted in Europe, America, Australia and other regions, and its process was named Technigalva. Currently, Zn Ni Si Bi has been developed on this basis, which can significantly suppress the Saintelin reaction during hot-dip galvanizing of silicon steel.
In the 1990s, Japan's Nippon Steel Corporation developed a zinc aluminum magnesium coating material called ZAM, which has a corrosion resistance 18 times that of traditional galvanized coatings and is known as the fourth generation of highly corrosion-resistant coating materials.
Process Fow
Workpiece → degreasing → water washing → acid washing → water washing → immersion in plating aid solvent → drying preheating → hot-dip galvanizing → finishing → cooling → passivation → rinsing → drying → inspection
Application
The hot-dip galvanizing process is widely used in steel plates, steel strips, steel wires, steel pipes, structural components, and parts products, and its application fields are quite extensive, such as light industry, household appliances, automobiles, construction industries, etc. In the automotive industry, it can be used for car body, shell, inner panel, floor, etc; Can be used for the shell and floor of various household appliances in the fields of home appliances and light industry; In the construction industry, light steel keel, building floor panel, corrugated board, rolling shutter door, etc. are used for various industrial and civil buildings.
