Tungsten-rhenium thermocouple details:
的分类。 1. Classification of tungsten-rhenium thermocouples . There are two types of tungsten-rhenium thermocouples listed in national standards in China:
A. Tungsten thorium 5-tungsten thorium 26. The nominal composition of the positive electrode is 95% tungsten, rhenium 5%, and the nominal component of the negative electrode is 74% tungsten and 26% tungsten. The division number is WRe5-WRe26, short for W-Re5 / 26.
B. Tungsten thorium 3-tungsten thorium 25, the nominal composition of the positive electrode is 97% tungsten, 3% thorium, and the nominal composition of the negative electrode is 75% tungsten, thorium 25%. The division number is WRe3-WRe25, short for W-Re3 / 25.
2. Use of tungsten-rhenium thermocouple. At present, when measuring temperatures above 1600 ° C, non-contact methods are often used. However, the error of this method is relatively large. If the contact method is used, the real temperature can be accurately measured. In high temperature thermocouples, precious metals
Thermocouples are expensive and the maximum temperature can only be below 1800 ° C. Tungsten-rhenium thermocouples not only have a high temperature measurement limit, but also have good stability. Therefore, tungsten-rhenium thermocouples are used in metallurgy, building materials, aerospace, aviation, and nuclear energy industries. Get wide
Pan application. China has abundant tungsten resources. Tungsten-rhenium thermocouples are inexpensive and can partially replace precious metal thermocouples. It is a promising temperature measurement material in the field of high temperature testing.
3. Use temperature. Its maximum operating temperature can reach 2800 ° C. However, when it is higher than 2300 ° C, the data is scattered. Therefore, the best use temperature is around 2000 ° C.
4. Use environmental atmosphere. Tungsten-rhenium thermocouples are extremely susceptible to oxidation and are suitable for use in inert or dry hydrogen, or they can be isolated from oxygen with a dense protective tube. Cannot be used in carbon-containing atmospheres (e.g. in hydrocarbon-containing atmospheres)
Use, the temperature will be corroded if it exceeds 1000 ℃). Tungsten or tungsten thorium is easy to form stable carbides in a carbon-containing atmosphere, which reduces its sensitivity and causes brittle fracture. In the presence of hydrogen, it will accelerate carbonization.
抗氧化。 5. Tungsten-rhenium thermocouple is resistant to oxidation. This problem has been a topic of concern to scholars at home and abroad, and is committed to research and solution. Our company has adopted the international advanced manufacturing process and successfully developed the assembled high temperature and high pressure W-Re thermoelectric
Occasionally, this project was rated as "Beijing Torch Plan Project" in 1999-2001 with project number 99353. The temperature range of this product is 0 ～ 1800 ℃, which is widely used in metallurgy, coking, chemical kiln, heat treatment, glass
In other industries, it has the advantages of high accuracy, low price, stable performance, and is not restricted by the working environment atmosphere. It is an ideal product to replace platinum and rhodium thermocouples. The W-Re thermocouple produced by our company has been hardened in Zhuzhou Cemented Carbide Factory, Zigong
Carbide plant and Shenyang Zhongkeyi and other units are widely used, and their performance reaches the level of similar foreign products. Its technical indicators are as follows:
1. Indexing number: W-Re3 / 25, W-Re5 / 26
2. Temperature measurement range: 0 ～ 1800 ℃
3. Temperature measurement accuracy: <± 1% t; <± 0.5% t
4. Time constant: ≥180 s
5. Insulation resistance:> 5MΩ
6. Specifications: 300, 500, 750, 1000, 1100 (mm)
Tungsten-rhenium molten steel rapid temperature measurement thermocouple is specially designed and manufactured for measuring the temperature of molten steel, molten iron and other metal melts. It has the advantages of small volume, fast response speed, high accuracy, and low price. Its technical indicators are as follows:?
1. Maximum temperature measurement temperature: 1800 ℃
2.Temperature measurement accuracy: ≤ 0.5% t
3.Insulation resistance: ≥30 MΩ
4.Measurement rate: ≥98%
5. Response time: <5 s
In particular, the W-Re thermocouples produced by our company are divided into three categories, one is a fine ceramic protection tube, the other is a pure molybdenum protection tube, and the other is a tungsten protection tube. The specifications of ceramic tube are: diameter of Ф8, Ф10,
Ф12, Ф14, Ф16, length 300 ~ 1100mm, this type of thermocouple can be used in any atmosphere for a long time without being restricted by the working environment atmosphere. Ф6, Ф8,
Ф10mm, length 500 ~ 700mm, this type of thermocouple can only work for a long time in the environment protected by vacuum, reduction or inert gas. Molybdenum tube is best used at a temperature below 1800 ℃ for a long time. The short-term use temperature can reach
2000 ℃; As for the tungsten tube, it can work at 2100 ℃ for a long time, but it is difficult to process and makes it very expensive. Please choose the thermocouple suitable for you according to our parameters.
是60年代发展起来的一种高温热电偶，有W/(W-26Re),(W-3Re)/(W-25Re),(W-5Re)/(W-26Re)和(W-5Re)/(W-20Re)等。 Tungsten-rhenium thermocouple is a high-temperature thermocouple developed in the 1960s. It has W / (W-26Re), (W-3Re) / (W-25Re), (W-5Re) / (W-26Re), and ( W-5Re) / (W-20Re), etc. Long-term use temperature is
2000 ～ 2400 ℃, short-term use up to 3000 ℃. Among low temperature thermocouples, the thermoelectric potential of (Au-2.1Co) / Cu thermocouples above 10K is greater than 10μV / K; gold contains a small amount (about 0.07 atomic percent) of iron
Thermocouples composed of gold and nickel-chromium alloys have a thermoelectric rate greater than 10 μV / K at liquid helium temperature (4K). (Pt-0.1Mo) / (Pt-5Mo), (Pt-1Mo) / (Pt-5Mo), and alloys using tungsten and 0.5 to 1 (atomic percentage) rhenium
Thermocouples made of alloys of tungsten and thorium can be used under nuclear irradiation. In addition to metallic materials, non-metallic materials such as graphite and refractory compounds can also be used as high temperature thermocouples. The advantages of such materials are high melting point and stable high temperature performance.
The thermoelectric potential and the rate of thermoelectric potential are high; the disadvantage is that the material is brittle, and graphite easily absorbs moisture to change the thermoelectric property, and the repeatability is poor. It is still under research and development. Such thermocouples are carbon / graphite, graphite / carbide, carbide / carbide, and the like.