Shield Tungsten Carbide

With the development of science and technology, the quantity demand and requirements of transport facilities, such as tunnels, subways, bridges and other infrastructure projects, has become higher and higher. Tungsten carbide has high hardness, high strength and excellent wear and corrosion resistance, so it has been widely used in those constructions. Shield tungsten carbide is a kind of tungsten carbide products, which usually assembled on the underground tunneling shield machine. Since unknown geological composition and shield machine is a kind of high-power equipments with large propulsion force, shear force, conventional tungsten carbide will be easily broken and fractured in the high intensity mixing thrust and shear forces. The common used shield tungsten carbide products are shield tungsten carbide buttons and shield tungsten carbide blade.

Shield tungsten carbide button is similar to common tungsten carbide button, but is has a broader application range, the force can be uniformly dispersed throughout the surface of the buttons, and it has better performance in wear resistance and toughness. Shield tungsten carbide blade is composed of tungsten carbide blade and steel base, which mainly withstand the squeezing, impacting, scratching and other effects caused by continuous changes in subsoil, water pressure. There is a experiment shows that the most important influencing factors as follow: one is the content of Co, the other is the granularity. According to the analysis of experimental data, the content of Co has a optimum range, below this range is correspondingly decreased shield carbide toughness and easily to be broken; instead, the Co content higher than this range, the strength of the shield alloy will drop and easily to be worn. The influence of grain size is also similar to Co content, too small grain size will cause the fracture of shield tungsten carbide; too large grain size will easily to be worn.

• < Prev
• Next >