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Why does the 304 stainless steel door rust?

In our life, stainless steel doors are popular with everyone because of their stainless and durable characteristics, and are now widely accepted by consumers.

When brown rust spots appeared on the surface of stainless steel doors, people were amazed: "Stainless steel is not rusted, rust is not stainless steel, and steel may have problems." In fact, this is a one-sided misconception about the lack of understanding of stainless steel. Stainless steel will also rust under certain conditions.

For example, in 304, in the dry and clean atmosphere, it has absolutely excellent corrosion resistance, but it is moved to the seaside area, and in the sea fog containing a lot of salt, it will soon rust; and 316 performs well. Therefore, it is not any kind of stainless steel, it can resist corrosion and rust in any environment.

There are several types of rust in stainless steel doors in daily life:

1. The surface of the stainless steel contains dust or other metal particles attached to other metal elements. In the humid air, the condensed water between the attached material and the stainless steel connects the two into a micro battery, which triggers an electrochemical reaction. The protective film is damaged, which is called electrochemical corrosion.

2. The surface of the stainless steel adheres to acid, alkali and salt substances (such as alkali water and lime water splashing on the wall), causing local corrosion.

3. The surface of the stainless steel adheres to the organic juice (such as melon, noodle soup, glutinous rice, etc.), and in the case of water and oxygen, it constitutes an organic acid, and the organic acid corrodes the metal surface for a long time.

4. In polluted air (such as the atmosphere containing a large amount of sulfide, carbon oxide, nitrogen oxide), in the case of condensed water, sulfuric acid, nitric acid, acetic acid liquid point is formed, causing chemical corrosion.

All of the above can cause corrosion of the stainless steel surface protective film and cause rust. Therefore, in order to ensure that the metal surface is permanently bright and not corroded, we recommend:


1. The surface of the stainless steel door must be cleaned and scrubbed frequently to remove the deposits and eliminate external factors that cause modification.

2, the coastal area should use 316 stainless steel, 316 material can resist seawater corrosion.

3. Some stainless steel chemical components on the market cannot meet the corresponding national standards and cannot meet the requirements of 304 materials. Therefore, it will also cause rust, which requires the user to carefully select the products of reputable manufacturers.

Thank you for your interest in our products.
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