Hot dip galvanizing production It can be said that the development of hot galvanizing process is closely related to the development of steel annealing process.
(1) Selas production line: Silas continuous hot-dip galvanizing production process and equipment, which is both available!For line internal annealing, the cold rolled sheet after annealing can be used for continuous hot galvanizing machine, group and process. It is American Silas companies in 1947 and put into production, due to its characteristic is using direct gas flame heating plate to annealing (use only when annealed plate roll preheat plates), and in direct heating method, also known as flames but due to the production process is complicated, especially in furnace temperature, high, easy to appear when parking burn out the phenomenon of strip steel, so the application is not common.
(2) Sharon method: Sharon method is a hot galvanizing production line built by Sharon steel company in 1939. It is characterized by spraying heated steel plates into the annealing furnace to shoot HCI gas, so it is also called gas pickling method. However, due to the use of HCI gas at a higher temperature, corrosion of equipment is easy to occur, which requires frequent maintenance and replacement of equipment at a higher cost. Therefore, this method is rarely used and popularized.
(3), Jimmy's method (Sendzimir) : 1931 poles, Jimmy, the annealing process and hot dip galvanized process, the tent together as a whole, Jimmy, who invented the world-famous for method, really opened up a continuous hot strip steel, plated zinc production in the new era, sen Jimmy's method is the line in the annealing is one of the most representative example, the line retreated inside furnace mainly includes two parts of the oxidation furnace, reducing furnace. Production process is divided into four sections: the strip oxidation furnace, directly by the gas flame in heated to a temperature of about 450 ℃, the reduction furnace with protective gas, the surface of strip steel iron oxide reduction cavernous pure iron, through reducing furnace steel strip heated to 700 c - 800 ℃ complete againCrystallization annealing, after cooling and without contact with air, directly into the zinc pot for hot galvanizing.The method has been widely used because of its high yield and good quality.
(4) American steel association (us.s): in 1948, American steel company designed and put into operation a production line of hot-dip galvanizing strip steel using the method known as American steel association. It is characterized by electrochemical degreasing, the annealing stage is only composed of reduction furnace and cooling part, and the heating part is radiated.
(5) modified sen kimmel method (MS): Armco of companies in the United States in 1965 in Silas method, on the basis of development, for the first time Jimmy method, modified sen called Jimmy method, its main characteristic is the sen Jimmy, independently of oxidation furnace and reduction furnace, linked by a smaller cross-sectional area of corridor, such, including preheating furnace, reducing furnace and cooling section of the annealing furnace and constitute a organic whole. In the 1960 s and 80 s, improved, Jimmy's method in hot galvanizing production accounts for absolute advantage In the late 1980s and 1990s, with the wide application of galvanized sheet in automobile industry, the quality requirements for galvanized sheet were increasingly highQuantity is preferred.