According to the World Steel Association, there are over 3,500 different steel grades, covering unique physical, chemical and environmental properties.
Basically, steel is composed of iron and carbon, although this amount of carbon, as well as the level of impurities and additional alloying elements, determine the properties of each steel grade.
Depending on the properties required for their application, different types of steel are made, and different sorting systems are used to classify grades based on these properties. Steel can be classified into four groups according to their chemical composition:
Carbon steels
Alloy steels
Stainless steels
Tool steels
Carbon steels
Carbon steels contain trace amounts of alloying elements and account for 90% of total steel production. Carbon steels can be classified into three groups depending on their carbon content: low carbon steels (up to 0.3% carbon); medium carbon steels (0.3-0.6% carbon); high carbon steels (over 0.6% carbon).
Alloy steels
Steel alloys contain alloying elements (such as manganese, silicon, nickel, molybdenum, titanium, copper, chromium, and aluminum) in varying proportions to control the properties of the steel, such as hardenability, corrosion resistance, strength, formability, weldability, or ductility. This group of steels includes structural alloyed 40хн2ma with high strength. Applications for gears, connecting rods, alloys and other heavily loaded parts.
Stainless steels
Stainless steels usually contain 10 to 20% chromium as the main alloying element and are highly corrosion resistant. With over 11% chromium, steel is about 200 times more corrosion resistant than conventional steel.
Tool steels
Tool steels contain varying amounts of tungsten, molybdenum, cobalt and vanadium for increased heat resistance and durability, making them ideal for cutting and drilling equipment.
