Newly signed major projects brighten up foreign contracting projects

1. Analysis of the causes of rust on the surface of stainless steel

The reason why stainless steel is not easy to rust is because stainless steel contains chromium, nickel, molybdenum and other elements. With these elements in the steel body, the internal molecular structure becomes more uniform, and the surface of the steel body will also produce a dense rich layer. The chromium oxide protective film greatly increases the corrosion resistance of the steel body, so it can greatly resist the corrosion of external acid corrosion products.

However, if the surface layer of the stainless steel body is damaged or retains some acid, alkali and other metal particles, and is exposed to the air for a long time, some rust will be produced. The main reasons for this phenomenon are as follows:

1. The surface of stainless steel adheres to acid, alkali, and salt substances (such as alkali water, lime water splashing on the decoration wall, welding slag splashing point, grinding slag, etc.), causing local corrosion.

2. Dust or metal particle attachments containing other metal elements are stored on the surface of stainless steel. When these attachments encounter water in the air, the two will be connected to form a micro-electricity.

The pool triggers an electrochemical reaction and destroys the chromium-rich oxide protective film on the surface of the stainless steel, which will cause rust marks.

3. The surface of stainless steel adheres to organic juices (such as melons, vegetables, noodle soup, sputum, hand sweat, etc.), which form organic acids in the presence of water and oxygen, and the organic acids will corrode the metal surface for a long time.

4. In polluted air (such as the atmosphere containing a large amount of sulfide, carbon oxide, and nitrogen oxide), it will form sulfuric acid, nitric acid, and acetic acid liquid spots when encountering condensed water, causing chemical corrosion.

5. In the process of stainless steel surface treatment, the polishing material contains iron ions. It is not cleaned up when leaving the factory and stays on the surface of the product. Rust spots will occur for a long time after encountering water in the air.

The above phenomena are all local corrosion on the surface of stainless steel. It will not cause deep damage to the stainless steel after a short time. You can wipe it with a scouring pad and a small amount of stainless steel cleaning solution. Apply a small amount of passivation solution to protect the surface of the stainless steel. Rust appears.

2. Treatment method of surface floating rust and cleaning points

1. When using cleaning chemicals to remove pollution and rust, please do a local "test wipe" in advance to confirm the cleaning effect. If the test results are satisfactory, then perform a comprehensive cleaning according to this method. And don't only clean the rusty parts, but also clean the surrounding parts as much as possible. If this is not done, the luster of the stainless steel surface will be uneven and the appearance will be ugly.

2. After using the cleaning liquid, the cleaning liquid must be completely rinsed with clean water. Do not leave the liquid on the stainless steel surface, otherwise it will cause secondary rust.

3. When using cleaning tools, it must be cleaned along the stainless steel grinding and self-parallel. If you do a round cleaning, the pollution is not easy to remove, and it will damage the surface gloss.

4. For steel cleaning tools or sandpaper, etc., although serious pollution can be removed, it is absolutely forbidden to use it, because it will damage the surface of stainless steel, and the fine iron powder remaining on the surface of stainless steel after use is more likely to regenerate the surface of stainless steel. rust.

3. Methods to improve the retention of other attachments on the surface of stainless steel:

1. Add a protective film on the surface of the product. After the installation is completed, the protective film will be removed after the possibility of dust or other attachments in the air is reduced. This method is suitable for regular products (that is, the surface of the product is regular flat).

2. Anti-fingerprint treatment is performed on the surface of the product. After the anti-fingerprint treatment, a solid protective film is formed on the surface of the stainless steel product, which can better protect the stainless steel from external attachments. Products with a width of 1m and a length of 2m can be processed.