With the trend towards industrial looks, there is renewed interest in weathering steel. Weathering steel, also known as weathering steel, has the appearance of natural weathering and rust. It creates interest and texture while complementing an industrial or engineering look.

Like any other building material, weathering steel has advantages and disadvantages. It is very important to know what weathering steel is and its properties.

What is weathering steel?

Weathering steel, sometimes called weathering steel, is a type of weathering steel that is resistant to corrosion. Due to its ability to form a protective coating against rust, weathering steel is a popular choice for outdoor sculpture, landscaping, structural facades and other outdoor applications. The protective layer, called verdigris, forms within just six months of exposure to oxygen and moisture.
Verdigris, which produces a dark brown coating, protects the steel from further corrosion from rain, snow, fog, ice, sleet and other weather conditions. In short, steel rusts, and rusting forms a protective coating. This layer is most effective when it is allowed to stabilize and build over time.

To produce the protective patina, the steel must be exposed to water and oxygen. When steel is exposed to elements, this protective rust layer takes only a few months to form. The coating is dynamic and continues to regenerate under different weather conditions.

Cor-ten is a trade name owned by US Steel that describes two main attractive advantages of the Steel: corrosion resistance and tensile strength. It was originally developed in the 1930s to help build coal wagons for the railroad.

The coal wagon adventure was a success, and Cor-Ten steel became the popular material of choice for outdoor art sculptures in the 1960s.

In addition to corrosion resistance, weathering steel eliminates the need for paint or additional weatherproof.

Why is weathering steel protective?


The patina formed on weathering steel has an inner and outer layer. The outer layer is constantly evolving and redeveloped with new non-adhesive rust prevention products. The inner layer is mainly composed of densely packed fine particles.

Eventually, the outer layer becomes less active and the inner layer starts to become more prominent. This is what gives weathering steel its unique look and texture. The outer layers weathered, and the inner layers became denser.


The inner layer is mainly composed of non-phase goethite, which is why the weathering steel has protective properties. Why is that? Because the rusted product becomes so dense that water can no longer corrode the internal steel structure.

Once well developed, the outer layer of weathering steel should be smooth and feel like a protective coating.