- Process & Technologies -

NITREG® is a modern heat-treating process, capable of meeting the metallurgical requirements of all nitriding specifications that may have been originally written for salt bath, plasma or traditional gas nitriding. The ability to control the concentration of nitrogen in the surface allows the user to control the growth of the compound layer virtually independently from developing a desirable diffusion zone. This approach facilitates not only meeting specification requirements, but it also makes it possible to improve on them by allowing for tighter tolerances, particularly regarding the thickness and properties of the compound layer.   The NITREG® Advantage

• Controls the thickness of the compound (white) layer and its properties
• Eliminates closed nitride networks within the diffusion zone
• Excellent control of the case depth

• Uniformly hardened even small bores, tight grooves and sharp edges

• Excellent control of surface hardness
• No parts distortion
• Very high level of process repeatability
• Green technology, no waste pollution

Nitreg®-C is based on the proven Nitreg® potential-controlled nitriding technology, whose ability to control processes and produce the desired properties of the nitrided layer has revolutionized the whole concept and practice of nitriding. This was achieved mainly by introducing superior process control and providing excellent properties to the nitrided layer. Nitreg®-C has shorter process cycle times than Nitreg® for the same expected specifications and is carried out predominantly on carbon and low alloy materials. Nitreg®-C is a nitrocarburizing process, which involves the diffusion of carbon and nitrogen into the steel surface simultaneously. The purpose of this treatment is to create a hardened superficial layer, enhancing wear and corrosion resistance, or improved fatigue resistance of treated steel or cast-iron parts, without distortion of shape or dimensional changes. In order to maintain a proper concentration of nascent nitrogen and carbon at the surface of metal, Nitreg®-C technology utilizes the Nitriding and Carburizing Potentials (KNand KC) control concept. It is often specified in industrial applications on the merit of its being an environmentally friendly but equivalent alternative to salt bath nitrocarburizing. The advantage of a KN and KC controlled technology is best evidenced when increased wear and/or corrosion resistance is sought. Such properties of the nitrided case are not only influenced by the thickness and relative phase composition of the WL, but also strongly depend on the relative level of porosity developed in the WL. KN control is essential in producing the desired WL configuration. Example of various porosity levels achieved through KN control   NITREG®-C Advantage:

• Accelerates formation of the compound (white) layer on low-carbon unalloyed steel
• Features low operational costs by utilizing more economic gas compositions
• Increases and stabilizes the ε-phase content in most types of steels
• Controls the thickness of the compound (white) layer and its properties
• Eliminates closed nitride networks within the diffusion zone
• Excellent control of the case depth
• Uniformly hardened even small bores, tight grooves and sharp edges
• Excellent control of the surface hardness
• No part distortion
• Very high level of repeatability of the process
• Green technology, no waste pollution

In-process post-nitriding/nitrocarburizing oxidation When resistance to atmospheric corrosion and an attractive black finish are the main requirements, ONC® is the best technology. Oxynitriding/oxynitrocarburizing transforms the very top portion of the white layer obtained with either Nitreg® or Nitreg®-C technologies into a complex spinel type structure consisting mostly of Fe₃O₄ type of iron oxide. As a result, the post-nitriding oxidation treatment has a net effect of enhancing the corrosion resistance of an already nitrided component. This integrated process (i.e. Nitreg® + ONC® or Nitreg®-C + ONC®) simultaneously enhances corrosion and wear resistance of steel, while giving the surface an attractive dark or black appearance, expressly desired by many customers. ONC® is a clean technology that, in many instances, can replace chrome plating and salt bath nitriding which may involve pollution and cost challenges. Depending on the type of steel, parts treated with the Nitreg® + ONC processes can easily pass well over 200 hours of salt-spray test per ASTM B117 before a corrosion spot appears.   ONC® Advantage

• Builds on the benefits of Nitreg and Nitreg-C
• Improves corrosion resistance
• Imparts an attractive black surface finish
• Enhances inherent wear resistance

Stainless steels respond to nitriding differently than other ferrous alloys, and there are significant differences within the stainless group as well. The primary reason is that, depending on the chemistry of the steel, it will behave differently with regard to the kinetics of layer formation, and it is a rather difficult process to control. In other words, unless you know what you are doing, you may end up with nothing, too little or too much case depth or white layer, or even damaged parts. NITREG®-S is a process in which any stainless steel may be nitrided, with complete control over the formation of nitrided layers. All types of stainless steel can be nitrided.   NITREG®-S Advantage

• No need for pre-processing parts preparation. In-furnace de-passivation and nitriding.
• Excellent wear resistance
• Improves fatigue strength
• Prevents galling
• Does not alter the alloy’s chemical composition
• Has no effect on the steel’s non-magnetic nature
• No change in colour, shape or size
• Controls the thickness of the compound (white) layer and its properties
• Eliminates closed nitride networks within the diffusion zone
• Excellent control of case depth
• Uniformly hardened even small bores, tight grooves and sharp edges
• Excellent control of the surface hardness
• Very high level of process repeatability
• Green technology, no waste pollution

Stainless steels have excellent corrosion resistance but possess relatively low strength and wear resistance. NANO-S™ expands their application range to include components that are subjected to intensive wear. NANO-S™ is a surface hardening process that improves the wear and galling resistance of stainless steel components without affecting inherent corrosion resistance. The process diffuses nitrogen and/or carbon into the surface of the steel, creating a new phase structure, the S-Phase, which provides extremely high hardness. Because NANO-S™ is a fully controlled process, there is no formation of chromium nitrides/carbides and consequently no loss of corrosion inhibiting properties. The treatment produces a hardened layer that is ductile and up to 25 μm deep (0.001"). Achieved at temperatures below 932 °F (500 °C), NANO-S™ does not induce distortion, which eliminates final machining. Finished parts are uniformly hardened even inside small bores, tight grooves, and at sharp edges.   NANO-S™ Advantage

• No need for pre-processing parts preparation. In-furnace de-passivation and nitriding
• Excellent wear resistance
• Improves fatigue strength
• Retains intrinsic corrosion properties
• Prevents galling
• Does not alter the alloy’s chemical composition
• Has no effect on the steel’s non-magnetic nature
• No change in colour, shape or size
• Controls the thickness of the compound (white) layer and its properties
• Eliminates closed nitride networks within the diffusion zone
• Excellent control of case depth
• Uniformly hardened even small bores, tight grooves and sharp edges
• Excellent control of the surface hardness
• Very high level of process repeatability
• Green technology, no waste pollution

Not sure which process or service is right for you? Contact our global team of heat treat experts and let them guide you or fill out the contact form to put you in touch with one of our experts!