Sometimes it is necessary to perform measurements under extremely high temperatures reaching 2000-3000 °С, in particular, in metallurgy, nuclear energetics and operation of different engines. WRT (wolfram-rhenium) has a good high-temperature strength, sensitivity and accuracy under high temperatures. These properties make the wolfram-rhenium thermocouple one of the best in its category.
Metotechnics offers wolfram-rhenium wire for thermocouples. For purchasing it call us, send a request via e-mail or make an order on the price list page on our website.
See the corresponding sections of this page for grades, production technologies, sizes, supply condition, applications of the described products.
Grades
Semi-finished products are produced of WR5 and WR20 wolfram-rhenium alloys. Wolfram (W) is its main components. The alloys differ in rhenium (Re) content. WR5 contains 95% of W and 5% of Re, WR20 - 80% of W and 20% of Re. The weight percent of admixtures and additions is extremely low and should not exceed 0,1%.
In some cases WR5 alloy is replaced with WAR5 that contains silica alkaline and aluminum additions. This allows making long measurements more precise.
The chemical composition of wolfram and rhenium is regulated by TC 11-75 standard.
Production
For producing thermocouple wire from wolfram and rhenium alloys drawing benches are used. Semi-finished products of the required size are made by pressurizing the blanks. As, according to the standard, such products should be supplied in soft condition, it should be annealed additionally.
Wolfram-rhenium thermocouple wire is supplied in two coils: one with WR5, the other one - with WR20. Certain coils are selected according to a special technique for determining the thermo-emf regulated by the standard as accurately as possible. The coupling, gradation and verification process are described in article Thermocouple. Types, properties, constructions, production”.
Product sizes, supply condition, properties, measurement ranges are given in standard TC 11-75, nominal static properties for corresponding thermocouples are given in GOST R 8.585-2001.
Properties
The range of measured temperatures: from +1300 °С to +2500 (+3000) °С. The maximum temperature of short-term application is given in brackets.
Operated in inert gases, dry hydrogen or vacuum. Can be used in oxidation atmosphere for a very short time.
Electrodes are insulated with ceramics made of beryllium, hafnium, aluminum, magnesium oxides.
Applications
WR wire is used for producing wolfram-rhenium thermocouple (WRT). They are used for measuring high temperatures up to 3000 °С. This type of thermocouples is used in the production of hard alloys and ceramics, melting of refractory materials, measurements in gas-turbine engines.
Prices
Cost section includes product grades and sizes and the price for the wire used for making electrodes of high-temperature thermocouples.
Calculate the weight of products made of thermocouple alloys
