Kanthal® Super RA
Kanthal® Super RA is specially designed to work in nitrogen at temperatures above 1,250ºC (2,280ºF). Other Kanthal Super molybdenum disilicide (MoSi2) heating elements have an excellent lifetime in oxidizing atmospheres but, when operating in nitrogen, nitration occurs.
Information
At temperatures above 1,250ºC (2,280ºF), the protective glaze is consumed and the silicon in the silicide of the elements may react with nitrogen forming silicon nitride, which can cause scaling. The speed of the process depends on the dew point and the time in the atmosphere.
The solution to these problems has been to run the element in air at high temperatures for a couple of hours to restore the glaze.
Kanthal® Super RA heating elements withstand nitration at high temperatures better than any other type of Kanthal® Super MoSi2 heating element. The nitration process still occurs, but to a 50% lower rate than for Kanthal Super 1800. The temperature, at which the weight reduction starts, is about 75ºC (135ºF) higher.
The element also has a substantially longer lifetime in all reduced and oxygen-deficient atmospheres and is characterized by a high tolerance in other aggressive environments.
Applications
Kanthal® Super RA heating elements is used in different types of sintering-, forging- and heat treatment furnaces.
Special features
- Longer life at high temperatures in reactive atmospheres
- Long life in all reduced and oxygen deficient atmospheres
- Can be used in nitrogen up to 1,700ºC (3,090ºF) at a 40ºC (105ºF) dew point
- Standard and specially designed elements