Description: It refers to the surface of a layer of zinc plated steel plate.

Categories:
According to production and processing methods can be divided into the following categories:
① Hot dip galvanized steel plate. The sheet steel is immersed in the melted zinc tank so that the surface is adhered to a layer of zinc sheet steel. It is mainly produced by continuous galvanizing process, that is, the rolled steel plate is continuously dipped in the plating tank with melted zinc to make galvanized steel plate.
② Alloyed galvanized steel plate. This steel plate is also made by hot dipping, but after the tank is out, it is immediately heated to about 500 ° C to generate an alloy film of zinc and iron. The galvanized sheet has good adhesion and weldability of coating.
③ Electric galvanized steel plate. The galvanized steel plate made by electroplating has good workability. However, the coating is thin and the corrosion resistance is not as good as that of hot-dip galvanized sheet. Galvanized plate
④ Single-sided plating and double-sided differential galvanized steel plate. Single-sided galvanized steel, that is, products that are only galvanized on one side. It has better adaptability than double-sided galvanized sheet in welding, coating, anti-rust treatment, processing and so on. In order to overcome the shortcomings of uncoated zinc on one side, there is a galvanized sheet coated with a thin layer of zinc on the other side, that is, double-sided differential galvanized sheet;
⑤ Alloy, composite galvanized steel plate. It is a steel plate made of zinc and other metals such as aluminum, lead, zinc, and even composite plating. This steel plate not only has excellent anti-rust performance, but also has good coating performance.
In addition to the above five kinds, there are color galvanized steel plate, printed coated galvanized steel plate, polyvinyl chloride laminated galvanized steel plate and so on. But the most commonly used is still hot dip galvanized sheet.

Function: Prevent the surface of the steel plate from being corroded to extend its service life.

Appearance:

 (1) Surface state: Due to the different treatment methods in the plating process, the surface state of the galvanized plate is also different, such as ordinary zinc flowers, fine zinc flowers, flat zinc flowers, zinc flowers and phosphating surface. The German standard also provides for surface grades.
(2) Galvanized sheet should have a good appearance, no defects harmful to the use of the product, such as no plating, holes, cracks and scum, more than thick plating, abrasion, chromic acid dirt, white rust, etc.

Mechanical properties:
(1) Tensile test:
① Performance indicators: Generally speaking, only structural, drawing and deep drawing galvanized sheets have tensile performance requirements. The structural galvanized sheet requires yield point, tensile strength and elongation, etc. Only elongation is required for stretching. For specific values, see the relevant product standards in “8” of this section;
(2) Test method: The same as the general sheet steel test method, see the relevant standards provided by “8” and the test method standards listed in “ordinary carbon steel sheet steel”.
(2) Bending test:
Bending test is the main project to measure the process performance of sheet metal, but the national standards for various galvanized sheet requirements are not consistent, the United States standard in addition to the structural level, the rest do not require bending and tensile test. In Japan, bending tests are required except for structural grade, building corrugated plate and general corrugated plate.
Requirements: Generally, after the galvanized sheet is bent for 180 years, the outer surface shall not be separated from the zinc layer, and the plate base shall not be cracked and broken.