Chemical element — tungsten, is located in the sixth group of the periodic system, it has an atomic weight of 183.84. It is one of the most heavy metals. It was prepared from tungsten anhydride by reduction with carbon. It has light-gray color with metallic luster. In nature it is found only in a mixture with several stable isotopes with mass numbers from 180 to 186.
|Atomic number W||The atomic (molar) mass g / mol||The degree of oxidation||Density [g / cm3]||Melting point t ° C||The boiling point of t ° C||The heat of fusion kJ / kg|
|number 74||183.84||0, 2, 3, 4, 5, 6||19.25||3422 ° C||5500 ° C||191|
Back in the 17th century, Europeans knew wolframite and scheelite — the most common tungsten minerals. In pure form, tungsten has been allocated until the end of the XVIII century., But has long remained a laboratory rarity until 1847 Oksland not patented obtain tungstic acid, sodium tungstate and tungsten from cassiterite. 10 Years Oksland patented the production of iron-tungsten alloys, formed the basis of modern high-speed steels. However, nearly half a century has not been able to implement these developments in production due to the high cost. In Russia, the Tungsten Steel Furnace was first in the Urals in 1865. At the end of the nineteenth century. urgent need for alloy and tool steels led to the launch of a line of high speed steels at the company «Bethlehem Steel». In 1900, samples of these alloys were presented at the World Exhibition in Paris, metallurgists hitting all developed countries. At the beginning of the XX century. Edison guessed used in incandescent tungsten filament. It was the beginning of the application of tungsten in electrical engineering. Today the tungsten is no longer a rarity, and took a firm place in everyday life. You can buy it at the best prices.
W refers to the group of refractory metals. All the elements in this group are characterized by a high melting point (over 2500 ° K) and high density index (above 8 g / m 3). Along with this, tungsten has a high hardness — 3430 MPa, as the metal, in comparison with other refractory elements are in this group of the periodic system, has the highest boiling point of 5828 ° K (5555 ° C). Among the metals of this group of tungsten it is one of the most expensive.
Typically tungsten is used in two ways. The first type — a porous metal is impregnated with copper or silver. Owing to the impregnation, the metal can be cut better at a speed that can reach 600 m / min. When compared with the second kind of tungsten — malleable and undoped, then the last maximum cutting speed was 90 m / min.
Additionally, tungsten alloys are divided into: monophasic and heterophasic. Monophasic alloys is considered alloys with some chemical elements (molybdenum, chromium, rhenium, and d. P). The most durable is an alloy in which the composition contains 15% molybdenum. Most plastic obtained by alloying an alloy of rhenium, its percentage in the alloy is approximately 26%. Regarding price for this type of tungsten, it is slightly lower than porous metals.
By heterophase alloys include those which include carbon and zirconium (niobium), as a percentage of 0,20−0,60 and 0.2−0.6, respectively. At temperatures below 2300 ° C of these alloys is released carbide fine particles, thereby improving high-temperature strength of such alloys also called dispersion-hardened.
Most often, the alloys whose composition is present in carbide WC, refers to group B. C. They come in different brands (VK6, BK8, VK6M, VK8M). In this case, B — the content of tungsten carbide, K — cobalt. In some markings found the letter M — fine-grained alloy has high wear resistance, but because of the fineness of reduced resistance to shocks. Alloys VC group is used for processing non-metallic materials, non-ferrous metals and their alloys, and iron. Buy tungsten alloy can be in any specialized points of sales.
Along with this, there are a few groups, such as TTC and TC. TTK- in this alloy composition contained titanium and tantalum carbides. They are used for the treatment of heat-resistant steels and titanium alloys.
TC group alloy differs from the TTC that only titanium carbide is present in its composition. These alloys are used when working with carbon steels, by means of turning and milling.
In view of the high cost of tungsten, are often used without tungsten alloys, they contain titanium carbide and other refractory metals (nickel, molybdenum, etc.).
More than 60% of tungsten produced is used to make stainless steel alloy, special steel tools. Often, for these purposes it is tungsten scrap. Tungsten consumable electrode used for welding all types of steels with AC and DC. The special color of the electrodes (golden, red, blue, gray, and so on. D.) Can be distinguished for what type of alloys are used, and what kind of power can be used.
Over the years, heat-resistant tungsten alloys are used for the heat-resistant coating machinery parts. Exceptional refractory and minimum surface evaporation enable the use of the metal for the yarn filament bulbs. Several chemical companies use it as a catalyst in organic synthesis. Along with this, the tungsten compound is used as a heat-resistant lubricant, fabric dyes as enhancing water resistance and fire resistance.
Buy at the best price
LLC «Electrovek-steel» sells a wide range of heat-resistant metal-roll. Our offices are located in Russia and Ukraine. Making a purchase is possible, without leaving the office, through the Company’s website. Technological equipment for each stage of production allows for individual orders, if the basic version product does not satisfy you. We make quality custom orders parameters, terms of their implementation are minimal. When wholesale purchases discounts.