GAS SULPHONITRIDING
Gas sulphonitriding is an original method of thermo-chemical treatment for steel and cast iron parts of machines and mechanisms.
The process is carried out in retort furnaces, in an atmosphere of ammonia and sulfur vapors, at temperatures ranging from 500 to 650°C, and for a duration of several to dozen hours. Therefore, we have two pit furnaces at your disposal.
GAS SULPHONITRIDING
Gas sulphonitriding method is used for the treatment of components made from all types of iron alloys, including both steel and cast iron. This technology is particularly recommended for the treatment of machine and mechanism components operating under dry or boundary friction conditions, such as worm gears, pins, camshafts, bearing bushings, valve guides and push rods, cam mechanisms, cylinder sleeves, and dies. The process can be applied to finished components.
By activating the surface through the despassivating (activating) effect of sulfur vapor added to the atmosphere of partially dissociated ammonia, we are able to extend the application range of gas nitriding and sulfurizing. This allows us to offer services for hard-to-nitride high-chromium steels (stainless steels, heat-resistant, and acid-resistant steels). In this way, hard diffusion layers with high resistance to galling and wear are consistently produced, suitable for applications in internal combustion engines (e.g., exhaust valves), as well as in components for power generation, the chemical industry, and food processing.
Max. working chamber size for gas sulphonitriding:
We offer the execution of gas sulphonitriding processes in pit furnaces with a maximum load capacity of 1800 kg gross, and the working chamber size is as follows.
Nitriding, gas sulphonitriding, tempering, aging, and annealing in a pit furnace:
h = max 1900mm
r = max 1000mm
GAS SULPHONITRIDING Process:
As a result of this process, a nitrided layer is formed, similar to the one produced by traditional nitriding. However, in the ε phase, iron sulfides are embedded, which are crucial for the operation of machine parts, as they separate the friction surfaces and reduce their adhesion. This leads to high wear resistance, low frictional resistance, and complete resistance to seizing.
This technology allows for broad control over the structure and properties of the surface layer by adjusting process parameters, primarily through the formation of an appropriate amount of iron sulfide in the ε phase. Gas sulphonitriding is a finishing process, and parts treated in this manner do not undergo any additional mechanical processing. The thickness of the layers formed on the treated parts typically ranges from 0.1 mm to 0.4 mm, depending on the material type, process parameters, and intended use of the components. Gas sulphonitriding can be applied to elements made of steel and cast iron.
The service properties of gas sulphonitriding layers are closely correlated with their specific structural makeup.
The diagram below schematically shows two basic variants of the structure of the surface layers of gas sulphonitrided elements, along with their division into individual zones.
Taking the above into account, it can be stated that the gas sulphonitriding technology guarantees:
- The creation of surface layers with the desired properties
- Complete elimination of part seizing in machinery
- High durability of components
- Reduced friction coefficient
Increased corrosion resistance - Improved fatigue strength
- Low process costs and reduced operating costs for machines and devices
- Unlike other technologies, this process does not cause pollution to the natural environment.
Additionally, it should be noted that the gas sulphonitriding process is safe for operators and does not require the organization of a special, segregated department.
