The appearance of the galvanized steel coil is that the chilled coil is a little bit faint. Cold rolled sheets such as surface quality, structure, and dimensional accuracy are better than chilled coils. Since the chilled coil obtained directly by the cold rolling process in the cold rolling process is work hardened during cold rolling, the yield strength increases and some internal stress remains, and the external appearance is relatively hard, so it is called chilled coil. . Cold-rolled coil (annealed state): the chilled coil is obtained by hood annealing before rolling, and the work hardening phenomenon and internal stress are eliminated (large drop) after annealing, that is, the yield strength is reduced to near cold. Before rolling.
(1) Galvanized steel coil has good air tightness and wide application
Because the steel silo is bent and bite by special equipment for the roll warehouse, it can ensure the quality of any part of the warehouse body in the process, so its sealing is particularly good, and it can store powder, such as cement, fly ash, slag ultrafine powder, etc. Materials are widely used in the building materials industry. Overall strength, stability, and shock resistance are superior to other warehouses. In addition, the material of the steel silo body is selected according to the requirements of anti-corrosion and grinding strength of the storage material, so that its normal service life is 15-20 years. Far more than the life of other warehouses.
The galvanized coil steel plate warehouse has a small footprint and is easy to manage. The galvanized coil steel silo is different from other steel silos, and the height and diameter can be arbitrarily selected within a larger range. The distance between the two warehouses is as small as 500 mm, making full use of space and reducing the floor space. The spiral bite steel silo has a high degree of automation, and is equipped with equipment such as temperature measurement and material level, which is very convenient for users to manage. High strength: the continuous spiral undercut of the steel silo is five times the thickness of the base metal, which greatly enhances the anti-load capacity of the steel silo.
It can effectively protect the plate from the incision and micro-cracks caused by cold working and the zinc burning area near the weld to prevent rust from starting here. Zinc has a melting point of about 420 ° C and a volatilization temperature of 908 ° C, which is not conducive to soldering and volatilizes when the arc is ignited. The volatilization and oxidation of zinc can cause pores, unmelted and cracks, and even affect arc stability, so the best way to weld galvanized sheet is to reduce heat input.
When welding the first layer of welds of the multi-layer welding, the zinc layer is melted as much as possible and vaporized and evaporated to escape the weld seam, which can greatly reduce the liquid zinc remaining in the weld. When welding the fillet weld, the zinc layer is also melted as much as possible in the first layer and vaporized and evaporated to escape the weld. The method is to first move the end of the electrode forward by about 5-7 mm, when the zinc layer is made. After melting, return to the original position and continue to weld forward. In the case of cross-welding and vertical welding, if short-slag welding rods such as J427 are used, the tendency of undercutting will be small; if the back-and-forth reciprocating strip technology is adopted, the quality of non-defective welding can be obtained.
(2) Galvanized steel coils have suitable mechanical properties
The strength and hardness of zinc itself are not high, but after adding alloying elements such as aluminum and copper, the strength and hardness are greatly improved. It is the appearance of zinc-copper-titanium alloy, and its comprehensive mechanical properties are close to or reach aluminum alloy and yellow. The level of copper and gray cast iron is also greatly improved in creep resistance. Therefore, zinc copper titanium alloy has been widely used in the production of small hardware. Mainly for die-casting parts, used in the production of parts for automobiles, construction, some electrical equipment, household appliances, toys, etc.
Many zinc alloys have excellent processing properties, and the pass processing rate can reach 60%-80%. Excellent medium-pressure performance, deep drawing, self-lubricating, extended die life, soldering or electric resistance welding or arc welding (need to be used in helium), surface plating, painting treatment, Good machinability. Excellent superplastic properties under certain conditions. Zinc and brass consisting of copper, tin and lead are used in machinery manufacturing. A zinc plate containing a small amount of elements such as lead and cadmium can be made into a negative electrode of a zinc-manganese dry battery, a printed zinc plate, a powder-etched photographic plate, and an offset printing plate.
(3) Galvanized steel coil has excellent resistance to atmospheric corrosion
At room temperature, a protective film is easily formed on the surface, so the largest use of zinc is in the galvanizing industry. It is mainly used for surface coating of steel and steel structural parts (such as galvanized sheet), and is widely used in automobiles, construction, shipbuilding, light industry and other industries. After the 21st century, Western countries began to try to use zinc alloy sheets as roof covering materials. The service life can be as long as 120-140 years, and they can be recycled. The service life of galvanized iron sheets for roofing materials is generally 5-10 years. . After the 21st century, the amount of hot dip galvanizing of steel strips has increased significantly.
Electro-galvanizing is also used, but the method is generally used for thinner coatings and different surface finishes. The use of zinc-containing coatings is another method of coating; for objects that are in continuous contact with water, such as large steel components used in ships, bridges and offshore oil and gas derricks, they only need to be connected to large zinc blocks. Protected, but the zinc block should be replaced regularly.
This post is also available in: Russian