What is the process parameters and application of tungsten-rhenium thermocouples _ instrument
Tungsten-rhenium thermocouples technology parameters of the temperature tolerance of tungsten-rhenium thermocouples temperature tolerance using temperature of 1300 ~ 1700 ℃ tolerance 0.
0 ~ 2300 ℃ 1% tolerance?
Insulation resistance at room temperature under normal temperature insulation resistance tungsten-rhenium thermocouples in the ambient air temperature is 20 and 15 ℃, relative humidity is not more than 85%, the thermal insulation resistance between the electrode and the external protecting tube should be greater than 100 m Ω.
The classification of tungsten-rhenium thermocouples in China listed in the national standard of tungsten-rhenium thermocouples has two kinds of tungsten-rhenium 5 -
Tungsten-rhenium 26, it is the name of the anode components in containing 5% 95%, rhenium, tungsten cathode nominal composition of containing 74%, 26% rhenium tungsten.
Index number of wre5 -
Wre26, abbreviated: w -
Tungsten-rhenium 3 -
Tungsten-rhenium 25, it the name of the anode components in containing 3% 97%, rhenium, tungsten cathode nominal composition of containing 75%, 25% rhenium tungsten.
Index number of wre3 -
Wre25, abbreviated: w -
Tungsten-rhenium thermocouples measuring temperature above 1600 ℃, the use of non-contact method is used, however, the method of error is bigger, such as contact law can accurately measure the true temperature.
In high temperature thermocouple, precious metal thermocouple is expensive and high temperature can only be under 1800 ℃, and tungsten rhenium thermocouple temperature measurement not only high ceiling, and good stability, therefore, tungsten-rhenium thermocouples in metallurgy, building materials, aerospace, aviation, and nuclear power and other industries are widely used.
Tungsten resources in our country, the tungsten-rhenium thermocouples cheap, can partially replace precious metal thermocouple, it is very promising in the area of high temperature test of temperature measuring materials.
Use its higher temperature can reach 2800 ℃ temperature, however, when higher than 2300 ℃, scattered data.
Therefore, the use of temperature in 2000 ℃ or so.
Tungsten-rhenium thermocouples used environment atmosphere extremely easy oxidation, suitable for use in dry inert or hydrogen, or with dense protection tube separate it with oxygen.
Cannot be used for carbon atmosphere (
As used in the atmosphere containing hydrocarbons, a temperature over 1000 ℃ or corrosion)
Tungsten or tungsten rhenium easy to generate stable carbides in carbon atmosphere, so that to reduce its sensitivity and cause the brittle fracture, the presence of hydrogen, will accelerate carbonization.