The steel grades of GB rails (U71Mn, U75VH, etc.) usually consist of four parts.
| Chemical Components % | |||||||||||
| Mark | C | S1 | Mn | P | S | ||||||
| U71Mn | 0.65-0.77 | 0.15-0.35 | 1.0-1.5 | ＜0.040 | ＜0.040 | ||||||
| Chemical Components % | |||||||||||||
| Mark | C | S1 | Mn | P | S | V | |||||||
| U75v | 0.71-0.80 | 0.50-0.70 | 0.75-1.05 | ≤0.025 | ≤0.025 | 0.04-0.12 | |||||||
The first part: "U", the symbol for rail steel, is the second letter in the Chinese pinyin "GUI" for "rail" (because the first letter has been used by rolling bearing steel).
The second part, "71", "75" and other numbers, represent the middle value of the carbon content range required by the standard.
The third part, "Mn", "V", "Cr", "RE" (referring to rare earth elements), "Mn2Si Cr Mo" and other letters combined with Arabic numerals represent the added alloying elements.
The fourth part, the last letter "H" of the steel grade, represents heat-treated rails, and if there is no letter "H", it is a hot-rolled rail.
In addition, the high-speed identification letter "G" is added after the steel grade to represent rails with a running speed greater than or equal to 200km/h.
As a professional supplier in the field of international steel trade, GNEE RAIL has long been committed to the global sales and service of GB standard rails. We can provide customers with a full range of railway rail products, from ordinary line rails to high-strength wear-resistant rails, with complete product specifications to meet the needs of railway construction of different levels.