JiangYin Dacromet Metal Products Co.,Ltd.
Understand Dacromet metal surface anti-corrosion and anti rust process
What is Dacromet surface treatment process, what is the difference between this surface treatment process and other metal surface treatment processes, and what is its special role?
What is Dacromet?
Dacromet is a transliteration of Dacromet, also known as Dacromet or Dacron. It is a new type of anti-corrosion coating for metal surface with aluminum, zinc and chromic acid as the main coating materials.
The base materials of Dacromet are mainly steel and nonferrous metals. After the coating solution reacts with the metal matrix, a layer of silver gray anti-corrosion film will be formed on its surface, which can isolate the matrix from the air and protect the workpiece.
Dacromet is widely used in various industries, such as construction, hardware, fasteners, road engineering, petrochemical and so on.
Dacromet has very strong anti-corrosion performance, which makes up for the short time of traditional anti-corrosion, and pushes the anti-corrosion technology to a new level.
Characteristics of Dacromet
Compared with some traditional electroplating processes, Dacromet has more advantages.
For example, the corrosion resistance of products with Dacromet process is dozens of times higher than that of traditional zinc plating. After salt spray test, it is found that ordinary Dacromet can reach 20 times of zinc plating, while those with long-term Dacromet will have a longer test time. Some parts in the nuclear industry use Dacromet process and their service life can reach 30 years.
Dacromet will not crack or fracture under tension and stress as other electroplating processes do.
In high temperature environment, cro has good stability, which is much higher than the traditional zinc plating.
After using Dacromet process, the product has very good impact resistance, so Dacromet process is very suitable for those stressed parts, because Dacromet has good permeability and can combine the surface coating with the product very well.
Different from some traditional electroplating processes, Dacromet has less pollution in the production process, so some highly polluted surface treatment processes are gradually replaced by Dacromet.
History of Dacromet
In the 1950s, due to the cold weather in some areas of the United States, the ground was frozen, so salt was spread on the road to reduce the melting point, so as to achieve the purpose of de icing.
However, after the sodium chloride in the salt melts, sodium ions will splash on the passing car, which will corrode the parts of the car after a long time, which will cause serious harm to the car and endanger the driving safety in the long run.
When scientists discovered the problem, they developed a new solvent, coating it on the metal surface, and then baking at high temperature will form a thin coating on the surface, and this is Dacromet.
Because of its excellent corrosion resistance, Dacromet was first used in various military equipment with high requirements for corrosion protection, and then it was widely used in other industries after continuous improvement.
Process flow of Dacromet
Degreasing and degreasing
The surface of workpiece with grease must be degreased and degreased. The effect of degreasing and degreasing will directly affect the adhesion and anti-corrosion quality of the whole coating.
Usually, the organic solvent mixed with trichloroethylene and industrial alkali is used for degreasing and degreasing. The workpiece can be degreased after soaking in the solution for half an hour. After the degreasing, the workpiece is taken out and the solution on the surface of the workpiece should be washed with clean water.
There will be some burr or rust on the surface of the workpiece. It is necessary to clean the surface, put the workpiece into the shot blasting machine or polish it directly by machine, which can improve the anti-corrosion ability of the workpiece.
Dacromet coating solution is mainly composed of aluminum, zinc, ethylene glycol and chromic acid, which are mixed and stirred before use.
Some small or standard parts are usually immersed in the coating solution for about ten seconds. After the surface of the workpiece is completely covered with the coating liquid, the workpiece is taken out. In order to avoid the phenomenon of liquid accumulation and sagging, the surplus coating liquid on the workpiece is removed by centrifugal force.
Some larger workpieces can not be completed by immersion, which requires the use of machine equipment to spray the coating liquid on the surface of the workpiece. The surface adhesion of the workpiece using spraying method is poor, and the corrosion resistance performance will also be reduced.
After the surface is coated with liquid, it should be baked at 120 ℃ for about 10 minutes, so as to slowly evaporate the water in the coating liquid, and make the coating liquid fully contact with the workpiece.
Then bake at 300 ℃ for about 30 minutes to fully solidify the coating solution on the surface of the workpiece, and finally form a thin film.
After high temperature curing, the temperature of the workpiece will be very high. To make the workpiece quickly cool through the cooling system, the workpiece after inspection will finish the whole Dacromet process.
Dacromet was born to provide better anti-corrosion performance for automobiles. It can be said that Dacromet has gone to the world through cars and improved many shortcomings such as galvanizing process, so it has been widely used. However, with the development of technology, people are still looking for better and more perfect electroplating process.