Types Of Steel and How They Are Made

steel roll coils

There is a wide variety of different types of steel, each one unique because of the way it is made or the type of ingredients it is made from. Each of these different types of steel has different strengths and levels of flexibility, and the best type of steel for a project depends upon the specific characteristics and requirements you are looking for from your steel product, whether its being used in the production of large commercial factories, or a state of the art architectural masterpiece.

The steel making process has evolved greatly over the years and refinements in steel production have made the availability and affordability of steel much greater in the past century.

How Steel is Made

Archeologists have found ancient steel samples dating as far back as 1400 B.C. Many ancient people relied on steel to make weapons and tools vital for hunting and preparing animals for food. There are two main types of metal: ferrous metals and non-ferrous metals. Ferrous refers to using iron as the main component, meaning ferrous metals are those composed mainly from iron. The most primitive technique for making steel was to melt down and combine wrought iron and cast iron. However, the amount of iron needed to produce this steel by product and the cost of providing these ingredients was so great that steel was hard to obtain and only available to the wealthy. Additional costs also lay in the smelting process. The quantity of coal needed to produce a strong enough heat to melt the iron also made steel somewhat of a luxury commodity.

As the industrial revolution swept America, and skyscrapers and other large buildings and monuments became a sign of industrial and economical superiority the need for a mass produced, sturdy and flexible building material grew exponentially. Time and effort began to focus on refining the steel production process and turning steel into the cornerstone of modern American architecture. It was discovered that coke, the ash and sulfur remains from coal could be used to heat metal as well as coal could and for a lot less than half the price.

In 1858 a man named Henry Bessemer discovered that a combination of iron ore and either limestone or anthracite could be smelted using coke as the reaction agent and the resulting product would be a strong yet flexible type of steel that did not rely solely upon iron as its main ingredient. This discovery propelled steel making in the multi-billion dollar industry we know it as today and confirmed that steel would become the backbone of the nation's building and construction industry.

The Different Types of Steel

Steel is what is known as an alloy, meaning it is not naturally found but instead is man-made, composed from a combination of different materials and metals. The type of steel achieved at the end of the steel making process depends upon both the different types of metals that have been melted together to form the final product and how these metals are heated, cooled and handled during production. The different types of steels range in price and are appropriate for different types of projects, such as whether the steel is used in building homes or making tools.

There are seven main types of steel

Stainless Steel

Stainless steel is among the cheapest metals to produce. One of the reasons stainless steel has become so popular in construction projects is the fact that it does not rust or breakdown when exposed to moisture, for this reason stainless steel is also known as corrosion resistant steel. Unlike other common forms of steel, stainless steel is made from chromium as opposed to carbon, which forms a protective layer over the inner layers of steel and provides stainless steel that non-corrosive power. Stainless steel is also commonly found in many famous works of architecture as it gained popularity during the Art Deco period due to its shiny and striking appearance. A third reason stainless steel is a popular building material is due to its highly recyclable nature. Stainless steel is 100 percent recyclable and the process of recycling the steel is actually very environmentally friendly.

Cobalt Steel

Cobalt steel is very similar in composition to High-speed steel, except with a higher concentration of cobalt. Cobalt is very temperature stable element, making cobalt steel highly ideal for steel pieces that will be subjected to extreme heat or friction. Much like stainless steel cobalt steel is also resistant to corrosion and other stains. However, cobalt is very hard and brittle, making it subject to shattering or cracking under extreme weight loads or forces of pressure. Cobalt has a distinctive bright blue color and most cobalt steel has a blueish tinge unless chemically treated after production.

Carbon Steel

Carbon based steel comes in two forms, high carbon steel and high alloy steel, both of which are extremely malleable and soft and also very cost efficient. Carbon steel and high alloy steel are the cheapest options on the market. Carbon steel is aptly named because the main component in this material is carbon, which presents a challenge as exposed carbon steel that is not properly protected from oxidation can easily rust and corrode. The higher the content of pure carbon the harder the steel itself becomes, but it also becomes less flexible and easy to shape and work with.

Carbide Steel

Carbide is a very strong element, with three times more strength when both elements are compared in their natural state. Carbide is often added to steel structures that require extra support. Carbide is also extremely dense making carbide steel a very heavy type of metal, not ideal for buildings or structure that require a light, flexible metal. Carbide is somewhat hazardous and if the element is inhaled in its dust form can cause fibrosis; for this reason carbide steel is produced under strict health and safety restrictions and should only be handled in its pure form by a professional who has experience with the element.

High-speed Steel

High-speed steel, also commonly known as HSS in the building industry, is commonly used to produce tools and other items subject to intense amounts of friction as it is highly resistant to abrasion. High-speed steel is highly affordable and often produced in large quantities.

Author: Conrad Mackie