The materials commonly used for 75KG GB heavy rails are mainly U75V steel and U78CrV steel. The following is a detailed introduction to them:
U75V steel
Composition characteristics: In addition to basic elements such as carbon and manganese, 0.04%-0.12% vanadium is added. Vanadium is a strong carbide-forming element that can form fine, dispersed carbides, play a precipitation strengthening role, and improve the strength and hardness of steel.
Performance advantages: Compared with U71Mn steel, U75V steel has higher strength and better wear resistance. Its structure is more refined, it can better resist wear and deformation, and its fatigue resistance is also improved.
Application scenarios: Commonly used in busy trunk railways and some heavy-load railways, such as railway lines for the transportation of heavy-load goods such as coal and ore, which can reduce rail wear and replacement frequency and reduce line maintenance costs.
U78CrV steel
Composition characteristics: carbon content is between 0.71%-0.82%, chromium content is between 0.40%-0.70%, and vanadium content is between 0.04%-0.12%. Carbon ensures strength and hardness, chromium improves corrosion resistance, oxidation resistance and hardness, and vanadium improves strength and fatigue resistance through precipitation strengthening.
Performance advantages: It is a high-strength rail material with a minimum tensile strength of 1080MPa and above. It has excellent wear resistance, fatigue resistance and corrosion resistance, and can better resist wear and deformation.
Application scenarios: It is commonly used in heavy-duty railways, such as the Daqin heavy-duty line section line, and busy trunk railways with high requirements for rail wear resistance and fatigue resistance. It can withstand large train loads, reduce the frequency of rail replacement, and reduce line maintenance costs.
The 75kg/m heavy rails used in the Daqin Line are mainly made of U78CrV, U75V, U95Cr, U22SiMn, U20Mn, etc. Among them:
U78CrV material: With its excellent performance and economy, it has become the preferred rail for the Daqin heavy-duty rail section line. It has high strength, fatigue resistance and wear resistance, and can better withstand the huge pressure and frequent impact of the Daqin heavy-duty trains, and is suitable for general sections of the section line.
U75V material: It is widely used in the Daqin heavy-duty rail section line. With the addition of micro-alloying element vanadium, it has a better effect on the straight lines of existing busy trunk lines and heavy-duty railways. In the switch area line, it can meet the use requirements of trains under complex working conditions such as frequent speed changes and turns, and has good stability and wear resistance.
