Nitriding
High wear resistance and surface hardness with minimal distortion – that is gas nitriding in a vacuum furnace, which we normally carry out after prior heat treatment so that the part meets both its functional requirements and tight tolerances. Thanks to lower temperatures than case hardening and a controlled environment, nitriding is gentle on the dimensions and shape of the part.
What is nitriding?
Nitriding is a thermochemical treatment in which nitrogen diffuses into the surface layer. At Kalírna Zlín we carry out gas nitriding in a vacuum furnace (not plasma nitriding) using ammonia (NH₃) and nitrogen (N₂). The process usually takes 10–85 hours, depending on the required layer and the type of part.
Nitriding hardness depth (NHD): according to the drawing (achievable range on request)
Result: very hard, wear-resistant surface, resistance to seizing, tough core retained
Why nitride with Kalírna Zlín
Vacuum furnace and gas atmosphere – consistent quality, uniform layer, batch-to-batch repeatability
Minimal distortion – lower temperatures and precise control of the heating/cooling curve
On-site laboratory – hardness and nitriding hardness depth measurement, metallography and reports
Technical advice – nitriding hardness depth design and protection of sensitive surfaces
Logistics – we offer a collection and delivery service
Typical parts and applications
moulds, shafts, gears, tools, levers and pins exposed to wear and seizing
parts that need a resistant surface combined with dimensional stability without subsequent grinding
How we proceed
Brief and consultation – drawing, required nitriding hardness depth, marking of functional surfaces and surfaces not to be nitrided, and inspection criteria
Process design – choice of cycle, time and gases (NH₃, N₂) in line with geometry and tolerances
Nitriding in a vacuum furnace – controlled gas atmosphere and holding time to reach the required depth
Stabilization and inspection – nitriding hardness depth and hardness measurement, metallography as required + report
What we need for an accurate quotation
drawing with the required nitriding hardness depth, measuring points and functional surfaces marked
material (steel grade) and quantity (pieces/batches)
information on previous/subsequent operations and the required documentation
No. At Kalírna Zlín we carry out gas nitriding in a vacuum furnace.
In our laboratory we carry out nitriding hardness depth and hardness measurement and, as required, metallographic evaluation. Results are documented in a test report.
Depending on the required depth and type of part, approx. 10–85 hours.