Steel

Vital to the construction and automotive industry, steel is one of the most recycled metals in the world – yet it is still responsible for a large proportion of global CO2 emissions.

Steel

Steel is used in many areas of our lives as an important engineering and construction material. It can be recycled multiple times without the deterioration of its physical or chemical properties. Primarily composed of iron and carbon, it can also contain metals such as manganese, nickel, titanium, chromium and molybdenum. There are four main widely known types of steel: carbon steels, alloy steels, stainless steels, and tool steels.

China is by far the largest producer of steel, accounting for more than six times as much as the next stop producing country. Despite the high level of recycling in the steel industry, its huge carbon footprint is a prominent environmental issue.

Main uses and applications

Steel is highly durable and has a low density in comparison to many other materials, making it particularly well suited for construction and automobile manufacture. Steel production has become much more energy efficient in recent years, with modern techniques requiring only 40% of the energy input of the 1960s.

There are a great number of different kinds of steel and multiple ways to categorise them, with one broad classification distinguishing between carbon steels, stainless steels, tool steels and alloy steels. Carbon steels have limited amounts of non-ferrous metals, with a carbon content of up to 2%. These types of steel are primarily found in automobile bodies, consumer appliances, and wiring. Stainless steels, by contrast, contains chromium as the main alloying metal, typically with 10% – 20% content. Around two thirds of global nickel production is consumed in the manufacture of stainless steel, as it significantly enhances corrosion resistance, ductility, and formability, allowing stainless steel to become a versatile alloy. Stainless steel is often used in the automotative industry and to manufacture domestic appliances, furnitures and medical equipment. Tool steels are physically treated to be very hard, strong and heat-resistant, specifically for manufacturing tools. Lastly, alloy steels are a broad family of alloys, which in addition to iron may also contain metals such as chromium, manganese, molybdenum, silicon, tungsten, vanadium.

Worldwide, steel is widely used in buildings and infrastructure, mechanical equipment, automotives, metal products, non-automotive transport such as trains and ships, electrical equipment, and domestic appliances. Global steel trade declined slightly in 2024 due to the constriction of the Chinese property construction market.