What are the factors that affect the passive film of 316 stainless steel plate?

What are the factors that affect the passive film of stainless steel plate? ? How much do you know about this problem? The following editor will talk to you about this issue, I hope it will help you.

1. Chloride ions and chlorine ions are very harmful to stainless steel. Therefore, we must strictly control the content of chloride ions in the passivation solution during the passivation process of the surface of the stainless steel plate. Harmful. Many chemical materials for passivation have limited requirements for chloride ions. The water used for passivation solution and cleaning water also have strict water quality requirements for chloride ions to ensure that the passivation products do not contain chloride ions.

2. The medium in the environment where stainless steel is used. The passive film of stainless steel is a suppressed metastable structure in thermodynamics, and its protective effect is related to the medium in the environment. However, no matter what kind of environment it is used in, the stainless steel plate must be cleaned regularly to remove harmful substances attached to the surface of the stainless steel plate during use.

3. The surface cleanliness of the 316 stainless steel plate. For stainless steel alloys, the smoother the surface of the stainless steel, the lower the roughness, the more difficult it is for foreign matter to adhere to the surface of the stainless steel. The foreign matter is not easy to adhere, so the corrosion of the stainless steel surface is reduced to the lowest point. Try to use a finished surface. In addition, the cleaning after the final passivation of the stainless steel plate should also be carried out carefully, so that the residual acid can promote the positive reaction, protect the integrity of the film layer, and ensure the corrosion resistance of the surface of the stainless steel plate.

4. The internal factors of stainless steel, we all know that the low nickel content in stainless steel, the passivation performance of stainless steel is low, so the martensite content and the content of chromium and nickel in the stainless steel have a great influence on the passivation performance of the surface of the stainless steel plate. .