When brown rust spots appear on the surface of stainless steel pipes, many people are surprised. They often think, "Stainless steel shouldn't rust. If it does, it must not be stainless steel, or there must be a quality issue." This is a misunderstanding. Stainless steel can rust under certain conditions. This article explores the reasons behind this phenomenon.
Causes of Stainless Steel Rusting
Electrochemical Corrosion:
Dust containing other metal elements or foreign metal particles can accumulate on the surface of stainless steel. In humid air, condensed water between these particles and the stainless steel forms micro-batteries, triggering electrochemical reactions that destroy the protective film on the steel. This process is known as electrochemical corrosion.
Organic Acids:
Organic juices (such as those from vegetables, noodle soup, or sputum) can adhere to the stainless steel surface. In the presence of water and oxygen, these organic substances can form acids that corrode the metal surface over time.
Chemical Corrosion:
Substances containing acids, alkalis, and salts (like alkaline water and lime water from wall decoration) can stick to the stainless steel surface, leading to local corrosion.
Polluted Air:
In environments with polluted air (containing sulfides, carbon oxides, and nitrogen oxides), condensed water can combine with these pollutants to form sulfuric acid, nitric acid, and acetic acid, resulting in chemical corrosion.
These factors can damage the protective film on the surface of stainless steel, causing it to rust.
Prevention Tips
To ensure that the metal surface remains bright and corrosion-free, consider the following:
- Regular Cleaning: Frequently clean and scrub the surface of decorative stainless steel to remove any attachments and eliminate external factors that could cause damage.
- Material Selection: Use 316 stainless steel in coastal areas, as it can resist seawater corrosion more effectively.
- Quality Products: Be cautious when selecting stainless steel products. Some pipes on the market do not meet national standards or the requirements for 304 materials, which can lead to rust. Choose products from reputable manufacturers to ensure quality.
By understanding these causes and taking preventive measures, you can maintain the integrity and appearance of stainless steel surfaces.
United Steel Industry As the most important steel pipe manufacturer and exporter in China, in the past 20 years, we have completed more than 100 projects, with partners in more than 100 countries, and established relationships with oil and gas and EPC companies in many countries business relationship.
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