Wind Power Steel

Hot dip galvanized steel sheet

Considering the production process and finished product packaging of hot-dip galvanized steel sheet, the hot-dip galvanized steel sheet may have some surface appearance defects as follows:

(1) Original plate defect

The surface defects of the original galvanized sheet, such as creases, pits and wavy edges, continue to affect the galvanized sheet and become its surface defects. Therefore, before production, the producer must inspect the original plate.

(2) Black spot

a. The purity of the zinc coating is not enough, and the metal impurities form a galvanic cell on the zinc surface. When it is beneficial to hydrogen evolution, it is easy to produce black spots on the zinc layer surface.

b. When the content of copper, iron, arsenic and other impurities in the zinc coating is high, these impurities appear black after passivation treatment.

c. Insufficient treatment of dirt and corrosion on the surface of the original plate forms residues, which makes some parts unable to be plated with zinc, resulting in defects of the zinc coating and easy to fall off, resulting in black spots.

d. Missing plating occurs during galvanizing, which is easy to form black spots during post-treatment.

e. The zinc plating solution is mixed with residue or small black ash (carbon or carbon compound), which adheres to the surface of the zinc layer or lives in the zinc layer and is firmly combined with the zinc layer. Black spots can be seen on the finished galvanized sheet.

f. Abrasion black spots. It is caused by rough operation during transportation and stacking.

(3) White rust

When the surface of galvanized steel plate is wet or immersed in rain, zinc is oxidized at a certain temperature to produce white powder. The anti-corrosion ability of the surface with white rust is greatly reduced, which affects its use.

(4) Uneven zinc coating

The zinc layer on the surface of galvanized sheet is uneven, uneven in thickness, and even small particles appear on the surface. There is excess liquid zinc on the surface of the strip steel from the galvanizing pot, which is blown off with an air knife (spraying high-pressure gas) to control the thickness of the zinc layer. The gas pressure of the gas knife, the distance between the gas knife and the strip steel, and the speed of the strip steel will directly affect the thickness of the zinc layer. If the air supply of the air knife is unstable or the air knife pressure is insufficient, the zinc coating will accumulate, i.e. zinc scar.

(5) Slag inclusion

There are residues or scum (metallic or non-metallic inclusions) in the galvanizing solution. Sometimes these slag inclusions are mixed in the galvanizing layer. Small round spots appear on the surface of Shanghai model ship model mechanical model industrial model, and even the original plate can not be stained with zinc, which is easy to cause iron dew points.

(6) Scratches and abrasions, etc

When the galvanized coil passes through the tension straightener, there are foreign matters on the straightener, causing surface scratches, scratches, etc.

(7) Chromic acid fouling

In order to improve the anti-corrosion ability of galvanized steel plate, a very thin passivation layer can be formed on the surface of steel strip, which can be completed by chromic acid treatment, i.e. chromizing treatment. However, if the chromic acid treatment is poor and there is residual liquid, there will be light yellow bands, stains or even black spots on the surface of the galvanized sheet.

Why choose us?

• Our Tower Plate products are designed to withstand the toughest environments and most challenging applications.
• We will follow the law of industry development and effectively integrate resources in order to maximize the synergistic effect and achieve harmonious, balanced and rapid development.
• We continuously strive to improve the quality of our Tower Plate products through innovation and research.
• We focus on practice, in order to stand out in the competition, always in the forefront.
• Our Tower Plate products represent the ideal choice for those seeking superior quality, reliability, and long-lasting performance.
• We focus on cultivating employee loyalty and personal development.
• Our Tower Plate products are engineered to perform optimally in even the most demanding and challenging environments.
• Our R&D team has continuously developed and improved according to the actual problems of customers, thus realizing various technological changes to achieve the goal of product optimization and upgrading.
• Our Tower Plate products are backed by a team of expert professionals who are committed to providing exceptional service and support.
• We recognize that with the development of global marketization, Wind Power Steel development must respond quickly to market needs.

Hot Tags: wind power steel, China wind power steel manufacturers, suppliers, factory