What material are rails made of?
1.Chemical composition of rails
The chemical composition of rails covers the five basic elements in steel - carbon (C), silicon (Si), manganese (Mn), sulfur (S) and phosphorus (P). At the same time, alloy elements such as chromium (Cr), vanadium (V), niobium (Nb) and residual elements in steel are also incorporated. The clever combination of these elements gives rails unique properties.
Regarding the naming of rail steel, the letter "U" stands for rail steel, which is the second letter of the Chinese pinyin of the word "rail" GUI. The number part represents the average carbon content, and the subsequent letters represent the alloying elements. For example, U75V rail means that its average carbon content is 0.75% and it is alloyed with vanadium.
2.The organization of rails
The organization of rails is crucial to their performance. Austenite organization is stable at high temperatures and has good plasticity. It is the organization expected by rail steel in high temperature environments. The structure of high manganese steel turnout is austenite. After water toughening, it can form a hardened layer under strong impact load and show excellent wear resistance.
On the other hand, pearlite is a mixture of cementite and ferrite, which is currently the mainstream structure in rail steel. However, martensite, although a quenched structure obtained by rapid cooling of austenite, is brittle and hard due to its needle-like morphology, and is generally regarded as a harmful structure and should be avoided as much as possible in rail steel.
3.Hot stamping marking technology
Hot stamping marking, an indispensable technology in rail production, directly stamps the marking information on the rail waist through high temperature and high pressure. This technology not only ensures the clarity and durability of the marking, but also provides strong support for the traceability and management of rails.
The furnace number, such as 043 2178, represents the year 2004, the No. 3 converter and the No. 2178 furnace; the continuous casting stream number is represented by numbers such as 1, 2, 3, 4; the continuous casting billet number is also distinguished by numbers such as 1, 2, 3, 4; the rail sequence number uses letters such as A, B, C to represent different rails rolled from the same billet. During the rail production process, it should be noted that cold printing is not allowed.
