Rail track is an essential component of rail track, and its function is to guide the train wheels moving forward by withstanding the enormous pressure pushed by the wheels. Steel rail shall provide smooth, stable and continuous rolling surface for the passing train wheels. In electrical railway or automatic block section, railway track can also be used as track circuit.
What type of steel is rail?
Rail is primarily made from high-carbon steel (or carbon-manganese steel) for its exceptional hardness, strength, and wear resistance, with common grades like 1084 or higher containing significant carbon (0.7-0.8%) and manganese (0.7-1%) for durability, plus special alloy steels (with vanadium, chromium) for extreme conditions like high-speed or heavy-haul lines.
Key characteristics:
- Composition: Rich in carbon and manganese to achieve high strength and toughness.
- Properties: Needs to withstand immense pressure, abrasion, and fatigue, requiring high wear resistance and fracture toughness.
Types:
- Standard: Medium-to-high carbon steel.
- Specialized: Alloy steels (vanadium, chromium) for demanding applications.
- Heat-Treated: Rails that undergo controlled cooling for refined microstructure and enhanced performance.
Typical material of train track steel
According to the steel type, rail material for railroad tracks can be divided into three types:
Carbon steel
carbon steel is a steel rail smelted and rolled with natural raw iron ore. It mainly uses carbon and manganese elements in the ore to increase the strength of the rail. Ordinary carbon train track steel is composed of 0.40%-0.80% carbon and manganese less than 1.30%-1.4%.
Alloy steel
The alloy steel is a steel rail that is smelted and rolled after adding appropriate amounts of alloy elements such as vanadium, titanium, chromium, and tin to the original iron ore. The strength and toughness of this type of rail are higher than that of carbon rail.
Heat-treated steel
The heat-treated steel is a steel rail that is formed by heating and controlling the cooling of the hot-rolled carbon rail or alloy rail. The pearlite structure of the heat-treated rail is more refined than that of the hot-rolled rail, resulting in higher strength and toughness. The hardened rail after heat treatment has a layer of hardening correction at the head of the rail, which greatly improves its mechanical properties so that the service life of the rail can be extended.
The chemical composition of train track steel
| No. | Element | Function |
|---|---|---|
| 1 | C | Improve the strength, hardness, and wear resistance of the rail. The carbon content of domestic rails is 0.65% to 0.82%. When the carbon content is relatively high, the steel becomes brittle, and its plasticity index will be significantly reduced. At the same time, it will increase the chance of white spots in the steel. |
| 2 | Si | It is easy to combine with oxidation and can play the role of removing bubbles in the metal. The steel contains an appropriate amount of silicon, which can improve the hardness and wear resistance of the steel. The content of domestic rail steel is generally 0159-0.9%, but too much content will make the steel hard and brittle, and it is easy to produce pores in the weld. |
| 3 | Mn | It is a beneficial element that can improve the strength and wear resistance of steel and increase the toughness of steel. It can remove harmful iron oxide and sulfide inclusions in the steel. The manganese content is generally controlled between 0.6% and 1.54%. Steel with a manganese content of more than 1.2% is called medium manganese steel, and its wear resistance is very high. |
| 4 | Cu | It is a beneficial element. Steel contains a small number of copper compounds, which can improve the fatigue resistance and corrosion resistance of steel. The copper content of domestic steel rails is generally between 0.10% and 0.40%. If the rolling process of the copper-containing rail is not good, fish-like cracks will occur on the surface of the rail |
| 5 | P | It is a harmful element. The biggest hazard of phosphide is to reduce the plasticity and toughness of the steel. Especially at low temperatures, the cold brittleness of the steel increases, which easily leads to broken rails, and its content is controlled at no more than 0.04% |
| 6 | S | The sulfur is a harmful element. It is often left in the steel in the form of granules. When the rail is rolled, it is rolled together with the steel into sheets, which causes delamination or longitudinal cracks in the rail. The amount of sulfur is controlled at no more than 0.05% |
Types of Steel Rail From GNEE RAIL
Since 2008, GNEE RAIL has been supplying steel rails of different grades for more than 18 years, steel rails from GNEE is highly recommened in China and abroad.Wtih cutting edge equipment, GNEE produces high quality steel rails that meet with requirements of most countries. Standard rail, head hardened rail, heavy rail,light rail,crane rail and other types are all available here, as one of the China main rail supplier, GNEE RAIL has been working on supplying economical green railway products all over the world.
| Classification | Height(mm) | Head (mm) | Bottom (mm) | Thick(mm) | Weight (kg/m) | |
| Light Rail | 8 KG/M | 65 | 25 | 54 | 7 | 8.42 |
| 9 KG/M | 63.5 | 32.1 | 63.5 | 5.9 | 8.94 | |
| 12 KG/M | 69.85 | 38.1 | 69.85 | 7.54 | 12.2 | |
| 15 KG/M | 79.37 | 42.86 | 79.37 | 8.33 | 15.2 | |
| 18 KG/M | 80 | 40 | 80 | 10 | 18.06 | |
| Classification | Height(mm) | Head (mm) | Bottom (mm) | Thick(mm) | Weight (kg/m) | |
| Heavy Rail | 38 KG/M | 134 | 68 | 114 | 13 | 38.733 |
| 43 KG/M | 140 | 70 | 114 | 14.5 | 44.653 | |
| 45 KG/M | 145 | 67 | 126 | 14.5 | 45.546 | |
| 50 KG/M | 152 | 70 | 132 | 15.5 | 51.514 | |
| 60 KG/M | 176 | 73 | 150 | 16.5 | 60.64 | |
| Classification | SIZE(mm) | theoretical weight | |||||||||
| height | bottom width | head width | waist depth | ||||||||
| Crane rail | QU70 | 120 | 120 | 70 | 28 | 52.8 | |||||
| QU80 | 130 | 130 | 80 | 32 | 63.69 | ||||||
| QU100 | 150 | 150 | 100 | 38 | 88.96 | ||||||
| QU120 | 170 | 170 | 120 | 44 | 118.1 | ||||||