Tungsten does not dissolve in water, hydrochloric acid and sulfuric acid

Tungsten wire carbide (WC) is the main raw material for the production of carbide, chemical formula WC. All known as Wolfram Carbide, also translated as tungsten carbide black hexagonal crystals with metallic luster, hardness of diamond is similar to electricity, a good conductor of heat. Melting point 2870 ℃, boiling point 6000 ℃, relative density of 15.63 (18 ℃). Tungsten does not dissolve in water, hydrochloric acid and sulfuric acid, soluble in nitric acid - hydrofluoric acid mixture. Pure tungsten fragile, if mixed with a small amount of titanium, cobalt and other metals, can be reduced brittleness. As tungsten carbide steel cutting tool, often by adding titanium carbide, tantalum or mixtures thereof, to improve the antiknock. Tungsten carbide is chemically stable.Extraction: tungsten metal powder and carbon black raw material, by a certain percentage dubbed mixture, the mixture into the graphite boat, placed in carbon tube furnace or a sense of high frequency electric furnace at a temperature carbonization , then by ball milling, screening that was carbide powder.Coarse-grained tungsten carbide formula WC, has some medium and fine grained WC powder different special properties and uses, especially high temperature WC with fewer structural defects, high hardness and micro strain etc, widely used in mining ground, oil drilling, lathe and so on. Hardness only to diamond, high value. Currently coarse grained WC production methods are:1 high temperature carbonization tungsten powder long carbonation, lattice defects can make the WC Molybdenum crucible the smallest micro-strain, WC plasticity improved. This is currently the main mode of production. Carbonization temperature should not exceed 1800-1900 ℃, in more than 1800 ℃, WC grain boundaries between the grains prone fusion grew, resulting in uneven distribution of WC grain size. Some studies show that reducing particle size of the tungsten material, increased carbonization temperature, carbonization time reduction, the quality can be improved to obtain a WC.