BP5 tungsten rhenium thermocouple wire

Buy tungsten rhenium wire BP5: price from supplier Evek GmbH

International Equivalent

Mark Analogue W. Nr. Aisi Uns En Order
VR5 WRe20 Delivery from the stock, in stock
BP20 WRe20 Delivery from the stock, in stock

The well-known aphorism "everything is learned by comparison" clearly illustrates the qualities of such alloys as BP5 and BP20.

Heat resistance of BP5 and BP20

It is the tungsten and rhenium that define the alloys' strengths. Tungsten is one of the most refractory, heavy and hard metals, melting at t° 3410 °C and boiling at the same temperature as the surface of the Sun: 6690 °C. Tungsten alloys lead all others in hardness and refractoriness. Tungsten is slightly inferior to rhenium, with a melting point of 3170 °C and boiling point of 5870 °C. Rhenium leaves the other metals far behind in heat resistance, demonstrating high strength and resistance to corrosion.

Alloying features

Alloying tungsten with 5% of rhenium improves ductility and increases the recrystallization temperature of the alloy - this is especially important when using it for the positive electrode of the thermocouple. Using the alloy as the negative electrode of a thermocouple to achieve maximum thermoelectromotive force requires a rhenium content of up to 35%, but no higher. Otherwise, at 1100 °C the alloy homogeneity is lost and the thermo-electromotive force is markedly distorted. In domestic metallurgy rhenium additive does not exceed 20%, which allows the use of tungsten-rhenium thermocouples at t° up to 2500 °C.

Resistance

Tungsten-rhenium alloy shows resistance to helium, argon, dry nitrogen and hydrogen. Alloying with silica-alkali additives can increase the stability of the alloy at temperatures up to 2000 °C by 2-3 times. BP5/20 sensors are capable of working in vacuum conditions. For more effective work in vacuum at 1800 °C and above electrodes with larger diameter should be used. BP5/20 are widely used as a differential thermocouple - can consist of two equal thermocouples, connected, as a rule, opposite each other. Such thermocouples are capable of measuring the temperature difference between two different junctions: working and conditional.

Thermo EMF

The nominal thermo-EMF at a temperature drop to 1600 ° C is also reduced to 24.59 mV at t = 1500 ° C is not more than 23.31 mV, and at t = 1400 ° C nominal thermo-EMF is 21.97 mV.

Disadvantages of BP5 and BP20

The disadvantages of these alloys include poor reproducibility of thermo-electric emf, due to which it is necessary to group thermocouples by categories: A-1, A-2, A-3. Category A-1 allows the use of the alloy at a maximum temperature of 2200 ° C, temperature use of A-2 and A-3 is limited to 1800 ° C. It is strictly prohibited to use wire from different batches, as each batch of wire has a "different" thermal EMF. Tungsten and rhenium are rare metals, so their cost is very high. The price of BP5/20 is much higher than the cost of thermocouples made of other materials, but still less than the cost of optical pyrometers for measuring and controlling temperature conditions in similar industrial conditions.

During the interaction of nitrogen and tungsten-rhenium alloy under vacuum conditions, it is necessary to maintain cleanliness and especially careful attention to the mandatory removal of organic substances and dust.

Application

BP5 and BP20 are used for the production of measuring and transducer devices, contact thermocouple sensors (TVR) for measurement of the highest temperatures in metallurgy - liquid metals. Up to 2500 °C. The measurement error is extremely low (±0.01 °C), which makes TVRs one of the most accurate instruments for measurements in such an aggressive environment.

Graduation table -thermocouple VAR-5 (VR-5)/VR-20 at t° of free ends 0 °C Table Nominal static conversion characteristic VR (A)-1.

Working end temperature t ° C T.e.d.mV, for temperature, °С T.a.d.mV, for temperature, °С T.E.D.mV, for temperature, °С T.a.d.mV, for temperature, °С T.a.d.mV, for temperature, °С T.a.d.mV, for temperature, °С T.a.d.mV, for temperature, °С T.E.D.mV, for temperature, °С
0 10 20 30 40 50 60 70
0 0 0,121 0,246 0,373 0,504 0,637 0,772 0,910
100 1,337 1,483 1.632 1,781 1,933 2,086 2,240 2,396
200 2,871 3,032 3,193 3,355 3,518 3,682 3,847 4,012
300 4,512 4,680 4,843 5,016 5,185 5,354 5,523 5,693
400 6,203 6,373 6,543 6,714 6,834 7,065 7,225 7,396
500 7,908 8,073 8,248 8,418 8,588 8,758 8,928 9,098
600 9,605 9,774 9,943 10,111 10,280 10,448 10,615 10.783
700 11,283 11,450 11,616 11,782 11,947 12,112 12,277 12,442
800 12,933 13,096 13,259 13,422 13,584 13.746 13,907 14,068
900 14,549 14,708 14,867 15,026 15,184 15,342 15,500
1000 16,125 16,281 16,436 16,590 16,744 16,898 17,051
1100 17,659 17,810 17,960 18,110 18,260 18,409 18,557
1200 19,146 19,292 19,438 19,583 19,728 19,872 20,015
1300 20,584 20,725 20,866 21,006 21,145 21,284 21,423
1400 21,971 22,107 22,242 22,377 22,511 22,645 22,778
1500 23,306 23,436 23,566 23,696 23,825 23,953 24,081
1600 24,588 24,713 24,838 24,962 25,085 25,209 25,331
1700 25,816 25,936 26,056 26,175 26,293 26,411 26,528
1800 26,992

Basic technical data

Temperature ° C Rated Rated power factor, mV Variation of teds from nominal, mV
1600 24,59 ±102
1500 23,31 ±99
1400 21,97 ±96

General data

Tungsten-rhee wire for thermocouple thermocouple electrodes annealed graded with nominal static conversion properties VR (A)-1 Wire meets specifications Yaeo.021.142 TU for production of thermocouples VAR-5 (VR-5)/VR-20

Recommendations for application

It is unacceptable to use thermocouples made of thermocouple wire from different series, even with the same nominal static characteristic of thermoelectrons.

Buy at the best price

Evek GmbH stocks a wide range of thermocouples. Our representative offices are located. You can make a purchase without leaving the office, through the Company's website. To purchase you only need to place your order and click the "buy" button. If necessary our managers can consult you on any current questions. They will give all necessary information concerning products, price range, and terms of realization. Lead time is minimal. In case of bulk purchases we provide discounts.

icoExperience of using tungsten thermocouples BP5/20 in high-temperature thermometry