• June 21, 2024
  • Shatou, Changan, Dongguan, CN
Stainless steel discoloration

Does stainless steel discolor?

Stainless steel is a material that finds wide usage in everyday life and industries, owing to exceptional corrosion resistance. However, sometimes we may notice stains on its surface. Have you ever wondered why stainless steel changes color? By delving deeper into the reasons that cause the tarnishing of stainless steel, we can gain a better understanding and protect this material better.

Reasons for the color change of stainless steel

The color change of stainless steel is mainly due to surface oxidation and corrosion.

1. Surface oxidation

The surface of stainless steel reacts with oxygen in the air, producing an oxide film that acts as a protective layer, preventing further oxidation. However, if this oxidized coating is polluted or damaged, it can result in discoloration, forming rust spots.

2. Corrosion

The main components of stainless steel are iron, chromium, and nickel. When the surface of stainless steel corrodes due to exposure to an acidic or alkaline solution, the iron element undergoes an oxidation reaction, releasing electrons to form iron oxide. The color of iron oxide changes depending on the degree of oxidation, ranging from light yellow to dark red, brown, etc.

Another common phenomenon is the appearance of blue-green rust spots on the surface of stainless steel in marine environments. This is because the water contains chlorine ions. When chloride ions chemically react with the iron element on the surface of the stainless steel, they form iron oxide, leading to a blue-green appearance on the surface.

Will stainless steel change color in salt water?

Stainless steel may corrode in saltwater. Although stainless steel is a corrosion-resistant material, it may still be subject to corrosion under certain special environmental conditions. When stainless steel is immersed in salt water for a long time, the chloride ions in the water may react with the iron element on the surface of the stainless steel to form iron ions, causing corrosion or green rust on the stainless steel.

Although this corrosion will not affect the corrosion resistance of stainless steel, it may reduce the aesthetics of stainless steel. To prevent stainless steel from discoloration, some measures can be taken such as cleaning the surface of stainless steel regularly, avoiding prolonged immersion in salt water, and using anti-rust agents.

How to prevent stainless steel from rusting?

To prevent stainless steel from rusting, the following measures can be taken:

1. Keep it dry

One of the reasons why stainless steel is prone to rust is moisture. Therefore, make sure that the environment is dry when you are on the countertop or when using stainless steel products.

2. Regular cleaning

Dirt may accumulate on the surface of stainless steel, and these substances may cause corrosion and rust. Regular cleaning of stainless steel surfaces with mild detergent and a soft cloth can help achieve and reduce the possibility of rust.

3. Avoid contact with strong acids and alkalis

Stainless steel is generally weak against acids and alkalis, but strong acids and alkalis may corrode it and cause rust. Therefore, direct contact between stainless steel and these substances should be avoided.

4. Use antirust agent

You can apply a layer of antirust agent on the surface of stainless steel products. This creates a protective film that reduces the chances of oxygen and moisture coming into contact with the stainless steel, thus reducing the risk of corrosion.

5. Control the use environment

When using stainless steel products, it is wise to avoid prolonged exposure to high humidity, high salinity, or corrosive gas environments. If the usage environment cannot be controlled, it is recommended to use higher-grade stainless steel products such as 316 stainless steel, which has stronger corrosion resistance.

6. Regular maintenance

Regularly check whether the stainless-steel products are damaged or scratched and repair the affected parts promptly to maintain their anti-rust performance. In short, it is essential to keep the products dry, clean them regularly, avoid contact with acids and alkalis, use anti-rust agents, choose suitable materials, and perform periodic maintenance to prevent them from rusting.

How to remove rust on stainless steel?

The method of removing rust on stainless steel is as follows:

1. Use white vinegar

Pour white vinegar on a damp cloth, then gently wipe the rust on the surface of the stainless steel with a damp cloth, then rinse with clean water and dry.

2. Use lemon juice

Pour lemon juice on a damp cloth, then gently wipe the rust on the surface of the stainless steel with a damp cloth, then wash it off with clean water and dry it.

3. Use baking soda

Mix baking soda and water into a paste, apply it on the rust, let it sit for a while, then scrub it with a brush, and finally clean it with water and dry it.

4. Use special stainless steel cleaners

There are special stainless steel cleaners available in the market, and most of them work well in removing rust when used as per the instructions. Regardless of the method, avoid using harsh cleaners or abrasives as they can scratch the stainless steel surface. Afterward, it should be thoroughly cleaned and dried after use to prevent any residual chemical substances from causing damage to the stainless steel surface.


Although some color changes may occur under certain conditions, it does not mean that stainless steel loses its characteristics and functions. Proper use and maintenance can help us maintain the beauty and durability of stainless steel.

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