Steel is one of the world’s most important materials. It’s used to make everything from screws and bolts to bridges, engines, airplane fuselages and more. Research, in fact, shows that nearly 2 billion tons of steel are produced annually. Not all steel is the same, however. There are many different steel alloys, each of which exhibits unique properties. What are steel alloys exactly?
The Basics of Steel Alloys
Steel alloys consist of steel with at least one other added element. All types of steel contain iron and carbon. Some of them contain just 0.05% of carbon, whereas other types of steel contain over 2% carbon. Regardless, steel is defined by its composition of both iron and carbon. It’s comprised mostly of iron with a small amount of carbon. A steel alloy refers to any type of steel that contains another added element.
Chromium Steel Alloys
Chromium is often used in steel alloys. Chromium steel alloys still contain iron and carbon, but they also contain the element chromium. Chromium steel alloys are referred to as stainless steel. Most of them contain about 11% chromium. With chromium, they offer a high level of protection against corrosion. Chromium steel alloys will develop a protective layer when exposed to oxygen. This layer prevents the underlying iron from succumbing to oxidation — something that could otherwise cause it to corrode or rust. There are several types of stainless steel. Regardless of type or grade, though, they all contain chromium.
Nickel Steel Alloys
In addition to chromium, nickel is used in steel alloys. Nickel steel alloys are comprised of iron, carbon and, of course, nickel. Like chromium steel alloys, they offer a high level of protection against corrosion. Nickel steel alloys, though, offer other benefits. They are usually stronger than chromium steel alloys, for instance, and they are oftentimes better protected from temperature-related damage. Nickel steel alloys aren’t as common as their chromium counterparts, but these properties make them desirable for many manufacturing and engineering applications.
Silicon Steel Alloys
You might be surprised to learn that silicon is used to make steel alloys. Silicon steel alloys are used in fewer applications than chromium and nickel steel alloys. Generators and electrical transformers may use them, but you won’t find them in many other applications. Nonetheless, silicon steel alloys offer some unique properties. For starters, they are magnetic. Their magnetic properties, in fact, make them useful for electrical-related applications. Silicon steel alloys are also relatively soft.