WRe5-WRe25 high-temperature oxidation resistant tungsten rhenium thermocouple

The WRe5-WRe25 high-temperature oxidation resistant tungsten rhenium thermocouple was first developed by GoedecKe in 1930. It is the most high-performance thermocouple among industrial thermocouples that can measure temperatures above 1800 ℃. At present, the technology of using Hoskins products from the United States and ARi physical anti oxidation tungsten rhenium thermocouples (protective tube: the outer protective tube is made of metal ceramic, with a usage temperature of 1600 ℃, mainly used in harsh environments such as coal gasification furnaces and sulfurization furnaces, and also used in situations where S-type or other low-cost thermocouples are not suitable for use containing H2S or SO2) is in use.

The use of WRe5-WRe25 high-temperature oxidation resistant tungsten rhenium thermocouple. When measuring temperatures above 1600 ℃, non-contact methods are often used, but this method has a large error. If the contact method is used, the true temperature can be accurately measured. In high-temperature thermocouples, precious metal thermocouples are expensive and the highest temperature can only be below 1800 ℃, while tungsten rhenium thermocouples not only have a high temperature limit but also good stability. Therefore, tungsten rhenium thermocouples are widely used in metallurgy, building materials, aerospace, aviation, and nuclear energy industries. China has abundant tungsten resources, and tungsten rhenium thermocouples are cheap and can partially replace precious metal thermocouples. They are a promising temperature measurement material in the field of high-temperature testing.

The maximum operating temperature can reach 2800 ℃, but data dispersion occurs above 2300 ℃. Therefore, the operating temperature is around 2000 ℃. Tungsten rhenium thermoelectric dipoles are prone to oxidation and are suitable for use in inert or dry hydrogen gas, or with dense protective tubes to isolate them from oxygen before use. Cannot be used in a carbon containing atmosphere (such as in an atmosphere containing hydrocarbons, where corrosion occurs at temperatures exceeding 1000 ℃). Tungsten or tungsten rhenium is prone to generate stable carbides in a carbon containing atmosphere, which can reduce its sensitivity and cause brittle fracture. In the presence of hydrogen gas, it can accelerate carbonization.

Classification of tungsten rhenium thermocouples. There are two types of tungsten rhenium thermocouples included in China's national standards:

1. Tungsten rhenium 5-tungsten rhenium 26 has a nominal positive electrode composition of 95% tungsten and 5% rhenium, and a nominal negative electrode composition of 74% tungsten and 26% rhenium. The division number is WRe5-WRe26, abbreviated as W-Re5/26.

2. Tungsten rhenium 3-tungsten rhenium 25, its positive electrode nominal composition is 97% tungsten and 3% rhenium, and the negative electrode nominal composition is 75% tungsten and 25% rhenium. The division number is WRe3-WRe25, abbreviated as W-Re3/25.

The Xuanxu Electric anti oxidation tungsten rhenium thermocouple is characterized by high temperature resistance and oxidation resistance. It can be used in oxidizing, reducing, or alternating atmospheres, and is inexpensive, only 1/2-1/4 of platinum rhodium couples.

High temperature oxidation resistant tungsten rhenium thermocouples are mainly used for temperature measurement in furnaces, coal gasification furnaces, or sulfur recovery devices in metallurgy, chemical engineering, refractory materials, and other industries.