The article starts with the use of galvanized steel sheet, introduces the classification of galvanized steel sheet, galvanizing process and corresponding uses, and at the same time, introduces the performance characteristics of galvanized steel sheet.
Due to its strong anti-corrosion performance, galvanized steel sheets are currently widely used in construction, household appliances, vehicles and ships, container manufacturing, electromechanical industries, etc., and have a good development prospect.
What is galvanizing?
Galvanizing has become an important method of steel corrosion protection, not only because zinc can form a dense protective layer on the surface of steel, but also because zinc has a cathodic protection effect. When the galvanized layer is damaged, it can still prevent base iron by cathodic protection material corrosion.
Galvanizing refers to a surface treatment technology that coats a layer of zinc on the surface of metals, alloys or other materials to play a role in aesthetics and rust prevention.
Zinc can form a film with good corrosion resistance on the surface in a corrosive environment, which not only protects the zinc layer itself, but also protects the steel matrix, and the zinc coating is non-toxic, inexpensive, and has excellent protective properties. Therefore, zinc plating occupies an important role in corrosion protection.
Uses of galvanized Steel Sheet
Galvanized steel sheet is a steel sheet with a hot-dip galvanized or electro-galvanized layer on the surface. It is now widely used in construction, vehicle and ship, container manufacturing, electromechanical and other industries.
A large number of galvanized sheets are used in automobile manufacturing, refrigerated containers, construction, ventilation and heating facilities, and furniture manufacturing.
For example, the back panel of the indoor unit of the air conditioner, the back panel of the cabinet, the inner parts, the outer casing and the interior of the outdoor unit, etc. are all made of galvanized sheet.
The working environment of these parts will encounter strong oxidizing conditions such as rain, sun, and warm gas corrosion. Under such harsh environmental conditions, galvanized steel sheets are often used to prevent corrosion.
Classification of galvanized steel
Galvanizing is still the main technology for anti-corrosion of steel products and products.
According to the production method, the galvanized sheet is divided into hot-dip galvanized sheet and electro-galvanized sheet.
Most of the anode materials used in hot-dip and electroplating are zinc. Because the standard electrode potential of zinc is low, the galvanized layer on the iron substrate is an anode coating in the general corrosive medium, which plays a role of electrochemical protection on the substrate.
Properties of galvanized steel
The surface of the steel is covered with a pure zinc layer with a certain thickness and a dense structure, which blocks the possibility of contact between the corrosive solution and the steel, thereby preventing the steel from being corroded by the solution.
The zinc layer will form a thin, dense and insoluble zinc oxide layer on the surface of the air, which can prevent the steel substrate from rusting due to contact with the air. In addition, if zinc oxide reacts with other components in the air to form insoluble zinc salt, it can also play a better anti-corrosion effect.
The iron-zinc alloy layer with dense structure and strong anti-corrosion performance can be used for marine construction and industrial anti-corrosion.
Zinc-iron has good abrasion resistance due to its strong bond and mutual dissolution.
Zinc has good ductility, and its alloy layer can be firmly attached to the steel substrate. Therefore, in industrial production, hot-dip parts can be rolled, bent, cold punched and wire-drawn, and the coating is not damaged.
After the steel structural parts are hot-dip galvanized, it is equivalent to an annealing treatment, which can effectively improve the mechanical properties of the steel matrix, eliminate the stress during the forming and welding of the steel parts, and is beneficial to the turning of the steel structural parts.
Excellent surface appearance
The surface of the galvanized steel plate is bright and beautiful. The galvanized sheet should have a good appearance and must not have defects that are harmful to the use of the product.
Such as no plating, holes, cracks and scum, excessive plating thickness, scratches, chromic acid dirt, white rust, etc.
Since many hot-dips galvanized products need to be welded, the weldability of the coating is also a very important property. The use of arc welding on galvanized steel sheets will cause pores and slag particles in the coating.
Although the galvanized layer does not need to be painted and used directly in most use cases, in some applications such as electric power and the automobile industry, the workpiece needs to be painted after hot galvanizing, so the paintability is also one of the galvanized Important performance.
Due to the galvanizing process, the life of the steel is extended. Both zinc and steel can be recycled without damaging the chemical and physical properties.
In summary, galvanized steel sheet has obvious advantages compared with ordinary steel sheet. Therefore, it has been widely used in construction, home appliances, vehicles and ships, container manufacturing, and electromechanical industries.