The main reasons for the blackening of stainless steel materials are as follows:
1. Oxidation reaction: Stainless steel is easily oxidized when its surface contacts oxygen in the air, forming an oxide layer, causing it to turn black. Especially in high-temperature environments or high-humidity environments, oxidation reactions are more likely to occur.
2. Foreign matter contamination: Long-term contact with materials containing chemicals such as acids, alkalis, and salts, or small metal particles and grease attached to the surface, can also cause the surface of stainless steel to turn black.
3. Failure to clean in time: If used improperly or not cleaned in time for a long time, dirt such as scale and grease on the surface will adhere to the stainless steel, causing oxidation reactions and causing the material to turn black.

There is a protective film on the surface of stainless steel, which can prevent stainless steel from rusting and other problems. If the protective film is damaged, the protective effect will be lost, leading to blackening, rusting, and other problems.
If there are some elemental dust, particles, etc. attached to the surface of the stainless steel, when the moisture is relatively heavy, the two will form a micro-battery effect, that is, an electrochemical reaction will occur. At this time, the protective film will be destroyed, causing the surface of the stainless steel to turn black corrosion.
If there are vegetables, noodle soup and other juices attached to the surface of stainless steel for a long time, organic acids will be generated due to water oxygen, which will also corrode the protective film on the surface. Similarly, if there are acids, alkalis, salts and other substances attached to the surface, it will cause Localized corrosion, resulting in blackening.

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