Varieties of Steel
A Quick Lesson –
Steel is one of the most common metals used for structural applications. It is strong, tough, ductile, formable, and weldable. As there are many different types of steel available, each with unique chemical and mechanical properties, it is important to know some of the key attributes of A36 steel.
According to the World Steel Association, there are more than 3,500 different types of steel, and about 75 percent of modern steel types have been developed in the past 20 years. At its most basic, steel is the combination of iron and carbon. However, the amount of carbon and the additional alloy ingredients determine the specific type of steel.
There are four primary groups of steel:
- Carbon steel
- Stainless steel
- Alloy steel
- Tool steel
- Carbon steels make up nearly 90 percent of all steel production.
- Carbon steels are further divided into three categories based on their carbon content: mild steels, medium carbon steels, and high carbon steels.
- Typically, stainless steels contain 10-20 percent chromium and have high resistance to corrosion, hence the “stainless” part.
- Stainless steels are divided into three sub-categories: austenitic, ferritic and martensitic
- Two of the more commonly used stainless steels in industrial applications are 304 and 316L. Although they are nearly indistinguishable to the naked eye, their differences are quite important with 304 being quite a bit more corrosive than 316L, which is just 304 with the addition of molybdenum to increase its strength and corrosion resistance.
- Alloy steels contain a wide variety of steel types, all containing varying amounts of alloying materials such as aluminum, chromium, manganese, nickel, and others.
- Alloy steels have a variety of strengths and weaknesses based on their makeup, including strength, resistance to corrosion, and weldability.
- Tool steels all contain some level of tungsten, cobalt, vanadium and molybdenum.
- These steel varieties have high resistance to heat and are extra durable, making them ideal for tools.