Large amount of slag production during the galvalume steel sheet process is a very troublesome thing. It will not only increase the workload of slag, but also to product quality has a great impact. To reduce the number of slag formation, we choose the raw materials with a smooth surface and less iron, oil and rust. This can strengthen the degreasing effect, also can adjust the temperature to reduce the amount of slag.
Measures to reduce the amount of slag produced during galvanizing are largely consistent with measures to prevent skip plating and white coating. Here CAMELSTEEL has largely summarized the following aspects:
1. Use raw materials with less iron powder and rust, improve the effect of pre-treatment and cleaning. And this also reduce the amount of iron powder and sponge iron entering the plating pot with the steel strip.
2. To choose the raw material with low carbon content and impurities. Because the raw materials with high content and impurities have very serious corrosion in the plating solution.
3. Strictly control the chemical composition of plating solution. Aluminum content should not be too high and silicon content should be low.
4. Strictly control the bath temperature and the temperature when put the strip into pot. Put the temperature as low as possible under the premise of ensuring the quality of products.
5. Strictly control the fluctuations and change of bath temperature. Accurately measure the bath temperature, and adopt pre-melting pot to pre-melting aluminum zinc ingot in advance, then flow into the pot after matching the ingredients.
6. Be careful not to put the oxide scale or other impurities on the surface of the strip enter into the pot during shutdown.
7. To improve the corrosion resistance of roller in plating pot and the machine, staff should select the material with good corrosion resistance. It is best to use the roller that spray ceramic materials, and put into the pot after the fully preheating of roller.
8. If the product is used as a substrate of color coated steel sheet, try to adopt the ingredients with low aluminum to produce galvalume steel sheet. The result is obvious. However, some companies use the method that reduce the aluminum content into about 33%, that is not appropriate. According to foreign information, the product with this composition has poor corrosion resistance.