1. The original principle is different
Hot-dip galvanizing: The principle is to immerse iron and steel parts in molten zinc to obtain a metal coating.
Cold galvanizing dao: The principle is to put the processed steel devices in a solution of zinc salt after degreasing and pickling, and after connecting the electrolysis equipment, use the electrochemical principle to deposit a layer of zinc on the steel devices.
2. Different equipment required
Hot-dip galvanizing: pickling equipment, bottom-drawing annealing furnace or bell-type annealing furnace.
Cold galvanizing: electrolysis equipment.
Three, performance and advantages are different
Hot-dip galvanizing: long-lasting and anti-corrosion, standard quality hot-dip galvanizing anti-rust thickness makes it have excellent durability; the toughness of the coating is strong, the hot-dip galvanizing layer forms a unique smelting metal structure, this metal The structure can withstand mechanical damage during transportation and use.
Cold galvanizing: has excellent environmental performance. Most cold galvanizing solvents and thinners do not contain highly toxic organic solvents, and the cold galvanizing process also reduces the volatilization of organic solvents, reduces drying energy consumption, and is beneficial to environmental protection.
Four, different applications
Hot-dip galvanizing: Due to its good anti-corrosion performance, hot-dip galvanizing is widely used in power towers, communication towers, railways, highway protection, street lamp poles, marine components, building steel structural components, substation ancillary facilities, light industry, etc.
Cold galvanizing: Cold galvanizing is the main development direction of the environmental protection of heavy anti-corrosion coatings.
1. The original principle is different
Hot-dip galvanizing: The principle is to immerse iron and steel parts in molten zinc to obtain a metal coating.
Cold galvanizing dao: The principle is to put the processed steel devices in a solution of zinc salt after degreasing and pickling, and after connecting the electrolysis equipment, use the electrochemical principle to deposit a layer of zinc on the steel devices.
2. Different equipment required
Hot-dip galvanizing: pickling equipment, bottom-drawing annealing furnace or bell-type annealing furnace.
Cold galvanizing: electrolysis equipment.
Three, performance and advantages are different
Hot-dip galvanizing: long-lasting and anti-corrosion, standard quality hot-dip galvanizing anti-rust thickness makes it have excellent durability; the toughness of the coating is strong, the hot-dip galvanizing layer forms a unique smelting metal structure, this metal The structure can withstand mechanical damage during transportation and use.
Cold galvanizing: has excellent environmental performance. Most cold galvanizing solvents and thinners do not contain highly toxic organic solvents, and the cold galvanizing process also reduces the volatilization of organic solvents, reduces drying energy consumption, and is beneficial to environmental protection.
Four, different applications
Hot-dip galvanizing: Due to its good anti-corrosion performance, hot-dip galvanizing is widely used in power towers, communication towers, railways, highway protection, street lamp poles, marine components, building steel structural components, substation ancillary facilities, light industry, etc.
Cold galvanizing: Cold galvanizing is the main development direction of the environmental protection of heavy anti-corrosion coatings.
Extended information
Process method of hot-dip galvanizing
1. Huilin Thermal Method
The Huilin thermal method includes lye degreasing, hydrochloric acid pickling, water rinsing, solvent coating, drying and other processing steps, and bell furnace annealing is required before galvanizing. The production process of this method is complicated, the production cost is high, and the corrosion resistance of the coating is affected, so this method has not been developed.
2. Sendzimir method
The Sendzimir method combines the annealing process and the hot-dip galvanizing process, with high output and good galvanizing quality. This method is widely used.
3. US Steel Union Act
The American Steel Union method uses an alkaline electrolytic degreasing tank to replace the degreasing effect of the oxidation furnace, and the rest of the process is basically the same as the Sendzimir method. This method is beneficial to furnace safety and reducing production costs, but affects the life of the furnace, so this method has not been widely used.
4. Silas method
The Silas method is to remove the oxidized skin on the surface of the strip with hydrochloric acid after alkali degreasing, and then put it into a vertical in-line annealing furnace for incomplete flame burning after washing and drying. A reducing atmosphere is created to quickly heat the strip to the recrystallization temperature, then the strip is cooled in a low hydrogen atmosphere, and finally immersed in a zinc solution for hot-dip galvanizing. But the production process is complicated, and this method is rarely used.
5. Sharon method
Sharon method sprays hydrogen chloride gas to the strip steel in the annealing furnace to make the strip reach the recrystallization temperature. However, because hydrogen chloride gas will seriously corrode equipment and cause high equipment maintenance and renewal costs, this method is rarely used.
6. Improved Senjimi
The improved Sendzimir uses a passage with a smaller cross-sectional area to connect the independent oxidation furnace and reduction furnace in the Sendzimir method, forming an organic whole with the preheating furnace, reduction furnace and the entire annealing furnace. The improved Senjimi method has the advantages of high quality, high yield, low consumption and safety.
Extended information
Process method of hot-dip galvanizing
1. Huilin Thermal Method
The Huilin thermal method includes lye degreasing, hydrochloric acid pickling, water rinsing, solvent coating, drying and other processing steps, and bell furnace annealing is required before galvanizing. The production process of this method is complicated, the production cost is high, and the corrosion resistance of the coating is affected, so this method has not been developed.
2. Sendzimir method
The Sendzimir method combines the annealing process and the hot-dip galvanizing process, with high output and good galvanizing quality. This method is widely used.
3. US Steel Union Act
The American Steel Union method uses an alkaline electrolytic degreasing tank to replace the degreasing effect of the oxidation furnace, and the rest of the process is basically the same as the Sendzimir method. This method is beneficial to furnace safety and reducing production costs, but affects the life of the furnace, so this method has not been widely used.
4. Silas method
The Silas method is to remove the oxidized skin on the surface of the strip with hydrochloric acid after alkali degreasing, and then put it into a vertical in-line annealing furnace for incomplete flame burning after washing and drying. A reducing atmosphere is created to quickly heat the strip to the recrystallization temperature, then the strip is cooled in a low hydrogen atmosphere, and finally immersed in a zinc solution for hot-dip galvanizing. But the production process is complicated, and this method is rarely used.
5. Sharon method
Sharon method sprays hydrogen chloride gas to the strip steel in the annealing furnace to make the strip reach the recrystallization temperature. However, because hydrogen chloride gas will seriously corrode equipment and cause high equipment maintenance and renewal costs, this method is rarely used.
6. Improved Senjimi
The improved Sendzimir uses a passage with a smaller cross-sectional area to connect the independent oxidation furnace and reduction furnace in the Sendzimir method, forming an organic whole with the preheating furnace, reduction furnace and the entire annealing furnace. The improved Senjimi method has the advantages of high quality, high yield, low consumption and safety.
