Kanthal Super is a dense cermet material consisting of molybdenum disilicide (MoSi2) and an oxide component, mainly a glass phase.
Kanthal Super heating elements have the ability to withstand oxidation at high temperatures. This is due to the formation of a thin and adhesive protective layer of quartz glass on the surface. When MoSi2 reacts with oxygen in the atmosphere, the layer of quartz glass is formed and under this a thin layer of molybdenum silicide with a lower silicon content Mo5Si3.
When Kanthal Super elements are operated at temperatures around 1200°C (2190°F) the material becomes ductile, whilst at lower temperatures the material is more brittle.
The silica layer possesses the capacity to clean itself from adhering impurities. If the impurities react with silica, the melting point will be lowered. The contaminated layer then flows down the element and drops off. A new silica layer is, however, spontaneously rebuilt.
Grades for demanding applications
Kanthal program of MoSi2 heating element includes several grades with specific features for use in demanding applications and atmospheres.
Kanthal Super 1700
Kanthal Super is a unique material combining the best properties of metallic and ceramic materials. Like metallic materials it has good heat and electrical conductivity and like ceramics it withstands corrosion and oxidation and has low thermal expansion. Maximum temperature 1700°C (3090°F).
Kanthal Super 1800
Same core characteristics as Kanthal Super 1700. Maximum temperature 1800°C (3270°F).
Kanthal Super 1900
Same core characteristics as Kanthal Super 1700, but has higher purity and a surface with better adhesion. Maximum temperature 1850°C (3360°F).
Kanthal Super ER
Kanthal Super ER is a new electric heating element with the unique ability to operate up to 1580°C (2875°F) directly in a wide range of furnace atmospheres from very dry reducing to oxidizing. With Kanthal Super ER heating elements it is possible, in just one furnace, to operate firing cycles where the atmosphere condition can be altered during the cycle between oxidizing, inert, carburizing, nitriding, reducing and rough vacuum.
Kanthal Super RA
Kanthal Super RA offers a long lifetime at high temperature in all reducing and oxygen deficient atmospheres. Specially designed for working in nitrogen atmosphere. Maximum temperature 1700°C (3090°F).
Kanthal Super HT
Kanthal Super HT is designed for a longer lifetime of small dimension elements in temperature cycling condi- tions. The hot strength and form stability is improved. The maximum operating temperature is 1830°C (3330°F), and the element is suitable for furnace temperatures between 1500 –1750°C (2730 –3180°F) approximately.