What Is Weathering Steel?

The Composition

Weathering steel is a low carbon steel that includes more elements than many other alloys available. It includes chromium, copper, and nickel. The low amount of carbon inside, generally at less than 0.3 percent, is what helps to keep it tough and ductile.

The other elements are what helps to give the steel alloy strength as well as corrosion resistance.

The Grades

There are several grades of weathering steel available. Something you should know about the grades, however, is that many are proprietary. They may only be available from certain companies. For example, COR-TEN is provided only by US Steel. They also have two grades of it – A and B.

The different grades are based on the amount of carbon and other elements inside. One grade could work more effectively for you in comparison to another grade based on the specifics of your project.

If you’re not sure which grade to use, it’s best to do some research. A supplier could also assist you with answering some of your questions. Various tests, such as a Charpy impact test, could also prove worthwhile to give you more insight into the grades of the alloy steel.

How it is Used

Weathering steel is used in structural elements because of its strength. Most commonly, it is used when the metal is going to be exposed to external elements without paint or anything else going on top. It can be used in bridge building, construction, and even outdoor statues. There is no limit to how it can be used, as long as it is used correctly.

This type of steel is extremely corrosion resistant. It is capable of outlasting traditional carbon steel in outdoor elements. It doesn’t need to be recoated or repainted like other alloys. Over time, a rust-like finish is created. The protective rust coating will actually slow down the rate of corrosion so that the design is capable of lasting for many years to come.

Understanding all of the characteristics of weathering steel is important. When you plan on building something that is going to be kept outside without painting it, you have to be realistic about the types of metal that you can use. If you use a metal that corrodes, you will end up with holes and rust throughout the structure, which will also impact the stability.

If you decide that weathering steel is the material you want to use, it’s important to find a supplier that keeps it in stock. You can determine the grading and the sizing that you need for your project. Plus, you will want to seek the most competitive prices possible.