Among the plants produced by Sabe Forni, there are nitriding furnaces. Nitriding is a process of cementation with nitrogen coming from partially dissociated ammonia that takes place with a temperature of 500-560°C on steel with a special composition (aluminium, chrome, molybdenum, vanadium) inside specific nitriding furnaces with the purpose of making its surface extremely hard through the formation of nitrides.
The processing time is very long (for example 1/10 mm of nitride layer in 8-10 hours). The nitride layer is composed of an external area with a higher level of nitrogen (white layer) and an internal area, with a lower hardness, but an excellent resistance. The white layer is fragile and has to be removed through the diffusion process, increasing at the same time the degree of dissociation and the treatment temperature.
Nitriding steel is a particular type of steel that has been hardened and tempered. With the nitriding process, elements are hardened and tempered, because with this treatment they don’t undergo neither oxidation nor dimensional changes and they can be directly used.
Nitriding furnaces are usually pit or horizontal furnaces, equipped with a metal case made of Ni-Cr steel. The nitriding process is also possible inside continuous furnaces.
The nitriding process requires the continuous control of nitriding potential through the measure of the dissociation of ammonia and hydrogen. In modern nitriding furnaces, the thermal cycle is controlled by a specific software, set with production recipes.
Contact our experts for further information about our nitriding furnaces.