Can stainless steel rust?

Stainless steel is a steel alloy that is stain resistant, oxidation resistant, and low maintenance cost. So it is favored in many applications, especially in applications where aesthetics are important. Even though stainless steel has antioxidant properties, it can rust. After all, it's "stainless steel," not "stain-free."

At present, there are more than 100 kinds of stainless steel on the market.

Some types of stainless steel may be more susceptible to corrosion than others, depending on the amount of chromium in the stainless steel. The higher the chromium content, the less likely the stainless steel is to rust. If the chromium content reaches 10%-11%. After the reaction of chromium and oxygen, a protective layer is formed, which makes the stainless steel have strong corrosion resistance and rust prevention ability.

In addition, if not properly maintained, stainless steel will rust over time.

What are the factors that affect stainless steel rust?

1. The composition of steel is the biggest problem in corrosion resistance.

Various factors can affect the corrosion resistance of stainless steel. The elements in different grades of stainless steel will have an adverse effect on corrosion resistance.

2. Metal use environment

Stainless steel use environment is another factor that will increase the possibility of stainless steel rust. Chlorinated environments such as swimming pools are highly corrosive. In addition, the saline environment will also accelerate the corrosion of stainless steel.

3. Maintenance will affect the rust resistance of the metal.

The chromium in the stainless steel reacts with the oxygen in the air to form a protective layer of chromium oxide on the surface. Although this layer is thin, it protects the metal from corrosion. Harsh environments or mechanical damage such as scratching can damage this layer, but if cleaned correctly in the right environment, the protective layer will form again, restoring protective properties.

How many types of corrosion stainless steel?

There are many types of stainless steel corrosion. Each type of corrosion presents different challenges and requires different treatments.

(1) General corrosion - This is the most predictable and easiest corrosion to deal with. It is characterized by uniform corrosion throughout the surface.

(2) galvanic corrosion - This corrosion will affect most metal alloys. It refers to a situation where one metal comes into contact with another and causes one or both metals to react with each other and corrode.

(3) pitting - this is a localized corrosion that leaves cavities or holes. It is common in environments that contain chlorides.

(4) Gap corrosion - it is also a local corrosion that occurs at the gap between the two connecting surfaces. It can occur between two metals or between a metal and a non-metal.

How to prevent stainless steel rust?

Metal rust looks unsightly, can be worrying to use, and can affect human health. Stainless steel is designed to resist corrosion, which is why most users get intimidated when they start to notice stains and rust on the metal.

At different stages, there are various ways to help the metal improve its rust and corrosion resistance.

1. Design before use

Before using stainless steel, preparation at the planning stage can ensure the long-term use of stainless steel. Make sure to use metal in areas with minimal water penetration to minimize surface damage. If contact with water is unavoidable, drainage holes should be used. The design should also allow free flow of air to prevent damage to the alloy.

2. Manufacturing process

In the process of manufacturing stainless steel, special attention should be paid to the surrounding environment to avoid cross-contamination with other metals. All components such as tools, storage units, runners and chains should be carefully monitored to prevent impurities from falling into the alloy. This increases the likelihood of rust.

3. Perform regular maintenance

After the alloy is installed, regular maintenance is key to rust prevention and can also limit the progression of any rust that may have formed. 

Use mechanical or chemical methods to remove the rust that forms and clean the alloy with warm water and soap. You should also apply an anti-rust coating to the metal.