What contribution did tungsten and molybdenum make to the construction of high speed car?
With the implementation of the high-speed train project, China will lead the world in the field of rail transit, which is naturally inseparable from the application of molybdenum, an important industrial raw material, and tungsten, "industrial salt".
Tungsten disulfide (WS2) and molybdenum disulfide (MoS2) superfine powders are often used as lubricants for carbon sliders of maglev trains. The two powders have similar layered structures, which are bonded by covalent bonds within the layers and bonded by van der Waals forces between the layers. The friction coefficient of the material is low because of the easy peeling between layers. The dynamic friction coefficient of WS2 is 0.030, and the static friction coefficient is 0.070. The friction coefficient of MoS2 is between 0.05 and 0.09. However, the two components are different, so the physical and chemical properties of other aspects are different, the former melting point, heat resistance and lubricity will be higher than the latter, more suitable for the application of harsh working environment in the friction parts.
The brake disc of maglev train is made of alloy steel, which consists of tungsten and molybdenum materials. The results show that tungsten is one of the important additives in alloy steel, and its content is less than 0.01%, which can improve the creep tension and thermal strengthening of steel at high temperature. Molybdenum is one of the main components of alloy steel, and its content ranges from 0.34 to 0.41%, which can improve the hardenability, thermal strength and creep strength of steel. Alloy steel brake disc has high mechanical strength and thermal fatigue resistance, but also has good thermal crack resistance, stable friction performance and good heat dissipation.
Profiled carbide for maglev train body. It includes floor, the floor has two symmetrical vertical plate, vertical plate at one end there are tilted plate, inclined plate surface near the end, open the chute, pay attention to the floor, vertical plate and the outer surface of the inclined plate paste a protective unit, and the protection unit is composed of sunscreen, waterproof and anti-corrosion layer from inside to outside, in turn, paste form. Cemented carbide is a kind of tungsten carbide powder as hard phase, cobalt, nickel, copper, iron as soft phase alloy, with high hardness, good toughness, wear resistance, heat resistance, excellent corrosion resistance and other characteristics.
In addition to tungsten and molybdenum products, brake discs, bolts, nuts, resistance temperature sensors and other components are also inseparable from the use of tungsten and molybdenum materials.
