Rail type

Since the invention of the rail in 1767, it has been more than 230 years. With the development of railway technology, the rail types have also undergone a process from flat to T-shaped to U-shaped. It was not until 1864 that it was finally fixed to be I-shaped.

Depending on the purpose, rail type can be divided into three categories:

rail type

1. There are 8 types of light rails for mine railways: 8 kg/m, 9 kg/m, 12 kg/m, 15 kg/m, 18 kg/m, 22 kg/m, 24 kg/m, and 30 kg/m.
2. The heavy rails for passenger and freight railways mainly include 38 kg/m, 43 kg/m, 50 kg/m, 60 kg/m, and 75 kg/m. In addition, there are switch rails for changing lines, there are two kinds of 50AT and 60AT.
3. There are four specifications of crane rails: QU70, QU80, QU100, and QU120.

According to the different materials selected, the rail type can be divided into different high-quality rails, and can be divided into three types: high-quality carbon rails, alloy rails, and full-length heat-treated rails:

1. High-quality carbon rails mainly use carbon and manganese to improve strength and toughness. The content of sulfur and phosphorus is controlled below 0.030%. The main grades are U74 and U71MN.

2. The alloy rail is based on carbon rail, adding appropriate alloying elements such as V, Ti, Cr, Mo, etc. to improve the strength and toughness of the rail. Our country’s alloy rail is RE-Nb rail, RE-Cr rail, and V-Ti rail, the main grades are U76RENB, U75V, and U76CrRE.

3. The full-length heat-treated rail is mainly based on the above-mentioned two kinds of rails. Through the heat treatment process of heating and controlled cooling, the internal structure is improved, the grains are refined, and the fine pearlite structure is formed so that the rail can obtain high strength and high strength. High toughness.

According to the mechanical properties of the rails, the rail type can be divided into two categories:

the first type of ordinary rails, which refers to the rails with a tensile strength of not less than MPa;

the second type of high-strength rails, which refers to the rails with a tensile strength of not less than 900MPa;

The third category is wear-resistant rails, which refer to rails with a tensile strength greater than 980MPa.