About steel
- Here are the answers to some of the most common questions about steel and the steel industry. You can also find definitions of steel terms in the glossary section.
- Can you recycle steel?
- Yes - very easily. Steel's unique magnetic properties make it an easy material to recover from the waste stream so it can be recycled. The properties of steel remain unchanged no matter how many times the steel is recycled. Steel is the world's most recycled material. The electric arc furnace (EAF) method of steel production can use recycled steel exclusively.
- How is steel made?
Most steel is made via one of two basic routes:
- Integrated (blast furnace and basic oxygen furnace).
- Electric arc furnace (EAF).
The integrated route uses raw materials (that is, iron ore, limestone and coke) and scrap to create steel. The EAF method uses scrap as its principal input.
The EAF method is much easier and faster since it only requires scrap steel. Recycled steel is introduced into a furnace and re-melted along with some other additions to produce the end product.
Steel can be produced by other methods such as open hearth. However, the amount of steel produced by these methods decreases every year.
- How many different types of steel are available?
- Steel is not a single product. There are currently more than 3,500 different grades of steel with many different physical, chemical, and environmental properties. Approximately 75% of modern steels have been developed in the last 20 years. If the Eiffel Tower were to be rebuilt today the engineers would only need one-third of the amount of steel. Modern cars are built with new steels that are stronger, but up to 25% lighter than in the past.
- Is steel environmentally friendly and sustainable?
- Steel is very friendly to the environment. It is completely recyclable, possesses great durability, and, compared to other materials, requires relatively low amounts of energy to produce. Innovative lightweight steel construction (such as in automobile and rail vehicle construction) help to save energy and resources. The steel industry has made immense efforts to limit environmental pollution in the last decades. Energy consumption and carbon dioxide emissions have decreased by one-half of what they were in the 1960s. Dust emissions have been reduced by even more.
- What is a finished product?
- Finished steel products are forged from semi-finished products. They are classified as follows:
- Cold-finished bars and flats (bright bars)
- Cold-finished sections including forged and cold-formed sections
- Cold-rolled narrow strip
- Cold-rolled plate and sheet in coil and lengths
- Deformed reinforcing bars
- Drawn wire
- Forged bars
- Forgings (unworked)
- Heavy sections, piling and welded structural sections
- Hot-rolled bars and flats in lengths
- Hot-rolled light sections
- Hot-rolled narrow strip including universal plates
- Hot-rolled rod in a coil (including reinforcement bar in a coil)
- Hot-rolled wide strip, plate and sheet
- Points, switches, crossings, tyres, wheels and axles
- Rails and rolled accessories
- Silicon electrical sheet and strip
- Steel castings (unworked)
- Steel tubes (seamless and welded, and steel tube fittings)
- Tinmill products
- Zinc- and other-coated sheet and strip
- What is a flat steel product?
- A flat steel product is typically made by rolling steel through sets of rollers to produce the final thickness. There are two types of flat steel products:
- Plate products. Vary in thickness from 10 mm to 200 mm. Plate products are used for ship building, construction, large diameter welded pipes and boiler applications.
- Strip products. Can be hot or cold rolled and vary in thickness from 1 mm to 10 mm. Thin flat products are used in automotive body panels, domestic white goods (for example, refrigerators and washing machines), steel (or tin) cans, and a number of other products from office furniture to heart pacemakers.
- What is a long steel product?
A long product is a rod, a bar or a section. Typical rod products are the reinforcing rods used in concrete, engineering products, gears, tools etc. are typical of bar products and. Sections are the large rolled steel joists (RSJ) that are used in building projects.
Wire-drawn products and seamless pipes are also part of the long products group.
- What is a mini-mill?
- A mini-mill is a molten steel producing process that feeds scrap steel into an electric arc furnace to re-process the material into finished steel for new applications. (See 'How is steel made?' above).
- What is a semi-finished product?
- Semi-finished products are solid blocks of steel, usually with a square or rectangular cross section. At a steel mill, the crude steel production process turns molten steel into ingots, blooms, billets or slabs. These are called semi-finished products. For definitions of these terms, see the glossary.
- What is steel?
- Steel is an alloy of iron and carbon containing less than 2% carbon and 1% manganese and small amounts of silicon, phosphorus, sulphur and oxygen. Steel is the world's most important engineering and construction material. It is used in every aspect of our lives; in cars and construction products, refrigerators and washing machines, cargo ships and surgical scalpels.
- Which company produces the most steel?
- worldsteel updates the list of major steel-producing countries in the annual World Steel in Figures publication. The latest edition is available in the Bookshop.
- Which country makes the most steel?
- worldsteel updates the list of top steel producers in the annual World Steel in Figures publication. For the latest table, visit the Bookshop.
- Who invented steel?
- It is not known who produced the first steel. Since 200 BC, many cultures have produced steel in one form or another. A British inventor, Henry Bessemer, is generally credited with the invention of the first technique to mass produce steel in the mid 1850s. Steel is still produced using technology based on the Bessemer Process of blowing air through molten pig iron to oxidise the material and separate impurities.
- Why does steel rust?
- Many elements and materials go through chemical reactions with other elements. When steel comes into contact with water and oxygen there is a chemical reaction and the steel begins to change to its original form - iron oxide. In most modern steel applications this problem is easily overcome by coating. Many different coating materials can be applied to steel. Paint is used to coat automobiles, and enamel is used on refrigerators and other domestic appliances. In other cases, elements such as nickel and chromium are added to make stainless steel, which can help prevent rust.
