What are the reasons for the rust of sa 179 ttst35n alloy schedule 40 seamless carbon steel pipe?

Sa 179 ttst35n alloy schedule 40 seamless carbon steel pipe sometimes rusts due to some external factors, such as electrochemical corrosion, organic acid corrosion, etc. The following is a detailed introduction to its corrosion reasons:

1. Electrochemical corrosion: Different types of attachments containing dust or metal particles of other metal elements are stored on the surface of stainless steel. In humid air, the attachments are connected with the condensed water of the stainless steel, and the two are connected to form a miniature battery, which triggers the corrosion of the stainless steel. Electrochemical reaction, the protective film is damaged, it is said to be electrochemical corrosion.

2. Organic acid corrosion: organic juice (such as loofah, noodle soup, sputum, etc.) adheres to the surface of stainless steel. In the case of water, oxygen, and organic acid, long-term organic acid will corrode the metal surface.

3. Local corrosion: The adhesion of the stainless steel surface contains acids, alkalis, and salts (such as alkali for decorative walls, splash of lime water), causing local corrosion.

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