A Closer Look at Steel Alloys
There are a ton of different alloy steel that are used in metal manufacturing industries. They can be developed in order to give steel different types of characteristics. Based on their elemental breakdown different types of steel alloys can be more or less malleable and respond differently to a variety of chemicals, temperatures or other conditions.
There are three primary types of alloys: austenitic alloys, ferritic alloys and martensitic alloys.
What are Austenitic Alloys?
An austenite or gamma phase iron is a solid solution of iron with an alloying element. Austenitic steel alloys are heated up to a temperature that causes crystal structure changes from ferritic alloys into austenitic alloys.
As a result of this process, the steel alloy is more capable of resisting corrosion. It also becomes a lot stronger through cold working. If you’re considering a certain type of stainless steel and want to know if it is austenitic, it’s pretty easy to figure out. The 200 series and 300 series of stainless steel are both austenitic alloys. They can be used for food utensils, surgical equipment, marine applications, watches, welding, automobile exhausts and various other applications.
What are Ferritic Alloys?
Ferrite, or alpha iron, is pure iron. A ferritic alloy is a steel alloy that cannot be hardened even under heat treatment. However, cold working can cause the steel to harden a little bit. Ferritic alloys tend to be corrosion-resistant and they are also known for having oxidative and ductile properties.
Ferritic alloys are part of the 400 series of stainless steel. They are used in automobile exhaust pipes and systems, welding applications, cutlery, automotive trim and elevated temperature uses.
What are Martensitic Alloys?
A Martensite is a particularly hard form of a steel crystalline structure, which is often formed by displacive transformation. It can be formed through the quick cooling off of austenite that does not give carbon atoms time to diffuse from the crystal structure. This process causes deformations in the structure, which strengthens the steel significantly.
It is both magnetic and ductile, but it does have its drawbacks. Martensitic alloys are only mildly resistant to corrosion, so that limits their usage somewhat. They can be hardened further through heat treatment and they are machinable.
Martensitic alloys are made up of about 12 to 14 percent chromium, less than one percent molybdenum, less than two percent nickel and less than one percent carbon.
Martensitic alloys are part of the 600 series, up to type 635.
Are there other types of alloys?
Yes, although they are a lot less common. One of the alloys is called duplex stainless steel and is a combination of austenitic and ferritic steel. In addition, there are precipitation-hardened stainless steels. These are created with a combination of chromium and nickel and can be hardened and strengthened significantly.
There are approximately 2,000 different types of stainless steels so the easiest thing to do in finding the right type of steel is to decide exactly how you need to use it and work from there. An expert should be able to narrow that down significantly until you have an easier choice based on the properties and behavior of a particular type of steel. Depending on whether you will only have to deal with natural elements, chemicals or other issues you can decide which type of steel alloy to use. Keep in mind that not only will you need to consider the applications of the steel once it is put into place, but also how malleable and formable it is for your needs. There are many factors to consider when picking a particular alloy.
Author Bio – I am Julia Wilson, native of Louisiana. Work as content writer for internet marketing for It Straps On, Inc. a Manufacturer of High Quality Stainless Steel Banding Strapping Systems and steel alloys.