Steel is one of the most widely manufactured and most commonly used materials in human history. However, most of us do not know much about steel. How it is made, the composition of steel, and its properties. We’ve answered the internet’s most commonly asked questions about steel.
No, steel is a not a pure element. Steel is made up of a variety of elements. Common elements that make up steel include iron, carbon, manganese, chromium, nickel, molybdenum, phosphorous, and many others. These combinations of elements, along with the way the steel is manufactured, make up a wide range of steel types.
Yes, steel is an alloy. An alloy is a combination of two or more metallic elements, or of a metal and a nonmetal, which give it greater strength, durability, resistance to corrosion, or other desired properties. There are thousands of different types of steel alloys, which are combinations of elements and manufacturing processes, which give the steel various desired properties.
Technically, steel is not a metal, because it is not an element. Steel is made up of a number of elements, which are metals. Merriam-Webter’s definition of a metal is “any of various opaque, fusible, ductile, and typically lustrous substances that are good conductors of electricity and heat, form cations by loss of electrons, and yield basic oxides and hydroxides… especially : one that is a chemical element as distinguished from an alloy”. As noted above, steel is an alloy, which means that it is not a metal because it is not an element. Examples of metals are found on the periodic table and include iron, nickel, copper, and manganese.
Steel is a liquid mixture when melted and a solid mixture at room temperature. A compound is a substance that is chemically bonded together. An example of this would be water – two hydrogen plus one oxygen atom. The iron, carbon, manganese, sulphur, chromium, or any other element that make up steel do not chemically bond together to form a new compound.
Because steel is an alloy, steel is homogenous. It is a mixture of many different metallic elements, which are all evenly distributed throughout the steel product. If steel was heterogeneous, the elements that make up steel would not be evenly distributed, which would cause the properties of the steel to vary from product to product.
There are over 3,500 different grades of steel with more being created every year. However most steel types can be categorized as one of the following.
For more detailed explanation of steel types, view our article on the different types of steel.
Steel is a ferromagnetic material. Ferromagnetic materials become influenced by magnetic fields, but do not have their own magnetic field, like a permanent magnet. Steel can be manufactured to be a permanent magnet, but most steel is not created to be magnetic. Steel is ferromagnetic because it is mostly made up of iron, which has an outer electron shell that is half full. Unlike other elements like helium, neon, and potassium that have full or mostly full outer shells, the electrons in iron’s outer shell can easily be influenced by a magnetic field to point in a single direction.
You can learn more about the magnetic properties of steel I n our Is steel magnetic article.
Yes, steel can be recycled. In fact, steel is an environmentally friendly material to manufacture compared to other similar materials and is one of the most environmentally friendly materials to recycle. The properties of steel remain unchanged regardless of the number of times that steel is recycled. Because steel can be magnetized, steel can be fairly easily recovered in landfills and during waste management processes.
Yes, steel is subject to rust. When iron (which is the primary ingredient of steel) is exposed to oxygen and water, it will go through an oxidation chemical reaction, which will form iron oxide. We commonly identify iron oxide as rust. Rust can form on steel both in the air or underwater. The chemical reaction is different underwater and creates iron hydroxide, and takes a longer amount of time. Carbon steel is typically coated in a protective layering to protect itself from rusting. Galvanized steel has a zinc protective coating for that purpose.
For a more detailed answer, visit our why does steel rust page.
Under the right circumstances, steel can burn. Steel is a great conductor of heat and electricity, so it is difficult to burn a regular sized piece of steel without reaching extreme temperatures. The heat is quickly dispersed among the rest of the steel, and the surface area of the steel is not able to reach a temperature where burning occurs. However, you can burn something with a small surface area like steel wool quite easily. Its volume is small enough where the steel can heat up to a temperature where burning occurs.
This is a great video that covers the subject:
In some cases, yes. Anodizing is a process that forms an aluminum oxide layer over a base material. This is most commonly done for aluminum. Stainless steel can be anodized to help protect the steel from regular wear and to improve its resistance to corrosion. Carbon steel should not be anodized, as it will corrode during the anodizing process.
Yes, steel is a conductor of electricity, however there are other more widely used metallic materials that are better at conducting electricity. Electric wires are typically made out of copper or aluminum because they are great conductors of electricity, and are available at relatively inexpensive prices. When compared to copper (copper having a conductivity of 100%), steel has a conductivity of rating of 3-15%.
Steel can be soldered, however the solder joints may become brittle in sulfur-rich environments. Carbon steel and low alloy steel have better solderability than high alloy steel and stainless steels. Typically, it is ideal to clean the steel surface with an aggressive flux before soldering.
Yes, steel does melt. In most steel manufacturing production processes, steel is melted before being formed into its desired shapes. The melting point of steel varies based on the type of steel alloy. Iron melts at around 2750 degrees Fahrenheit while carbon steel melts between 2,600 – 2,800 degrees Fahrenheit. Stainless steel melts at 2,750 degrees Fahrenheit.
Yes, the primary element in steel is iron. For example, 1018 steel – a common steel grade – has an iron composition of 98.81-99.26%. While other types of steel are known for having various levels of other elements like carbon, and manganese, the vast majority of carbon steels have iron contents above 90%. Stainless steels have the lowest levels of iron, with some stainless steel alloys having less than 50% iron. However, most stainless steels have iron contents of 70-90%.