Nitrogen reacts with the iron and other alloys on the surface, forming strong nitrides that protect the surface of the material. Mid-South Metallurgical is proud to offer one of the most advanced methods for case hardening steel components in the heat treating industry today-ion nitriding. Disassociated Ammonia is the source of atomic Nitrogen that is diffused into the part surface to create a hardened case that is wear resistant and corrosion resistant. The chemical changes brought on by case hardening are responsible for the added hardness of a part’s surface. with the derivative nitrocarburizing process, nitriding often is used in the manufacture of aircraft, bearings, automotive components, textile machin-ery, and turbine generation systems. This case hardening process is also termed as plasma ion nitriding or ion nitriding or glow-discharge nitriding. There are two forms of nitrocarburizing: austenitic and ferritic. Main Difference – Carburizing vs Nitriding. Due to their shape and size, carbon atoms cannot diffuse into the part in this low-temperature process. To put it simply, plasma nitriding utilizes a Direct Current electricity source to break up nitrogen gas (N2) into nitrogen ion (N+). Because the part is heated into the austenitic range, a phase change occurs and carbon and nitrogen atoms can diffuse into the part. About Nitriding. It’s easy to get lost in the chemistry—and the nomenclature—behind heat-treating processes. Copyright © 2006 TPP Information Centre. UltraGlow® Ion Nitriding (also known as Plasma Nitriding) is a case-hardening treatment which uses glow discharge technology to introduce nitrogen ions to the surface of a metal for diffusion into the part. Why Choose Nitrocarburization Over Other Processes? It is a very reactive medium, which contains ions, very energetic neutral particles, as a result of dissociation (separation) of gas molecules in an electric field. Nitriding is a lengthy process and, depending on the case depth requirements, may take 4 to 60 hours or more. The glow discharge at the surface of the steel part produces atomic nitrogen by ionisation of the ammonia gas. Also, no separate heating is required as the plasma provides sufficient heating of the component's surface to reach the process temperature of typically 500°C. Particularly when applied to higher alloyed steels, plasma nitriding imparts a high surface hardness which promotes high resistance to wear, scuffing, galling and seizure. In Micropuls® plasma nitriding, we use the processes of PLASNIT® and … Nitriding is another thermochemical heat treating process. Plasma nitriding can be further branched out into plasma nitrocarburising. While the science behind…, One of the most critical parts in the heat treatment of a metal part is the quench, or the rapid…, Heat treating 101: An introduction to heat treating procedures, The salt bath nitriding process and its safer alternative, Managing the risk of cracking in heat treating, The basics of oil quenching in heat treating. Gas nitriding is arguably the more versatile case hardening option. Nitriding produces hard, highly wear-resistant surface (shallow case depths) of product with fair capacity for contact load, good bending fatigue strength and excellent resistance to seizure. This is because voltages had dropped sharply at these regions. Carbonitriding is used to harden surfaces of parts made of relatively cheaper and easily-machined steels, like stamped automotive parts or wood screws. Plasma nitriding can also clean the surface by sputtering. The nitrogen ion, N+, will then diffuse into the metal surface as finely dispersed nitrides, imparting high hardness to the surface. Fig.2 shows a job part undergoing plasma nitriding treatment. While nitrocarburizing and carbonitriding may seem complicated, they’re also critical to ensuring parts can stand up to the environments in which they’ll be used. The process makes parts more resistant to wear and increases fatigue strength. This eliminates costly cleaning or grinding to remove the brittle white layer associated with traditional nitriding. It is an extension of conventional nitriding process, utilizing plasma discharge physic to diffuse nitrogen into the surface of a ferrous alloy. Atomic nitrogen is then further converted into nitrogen ion through plasma ionization. It is a type of industrial process involved in altering the chemical and physical properties of metals and metal alloys.There are four major types of heat treatment methods as annealing, tempering, hardening, and normalizing. NITRIDING These processes are most commonly used on low-carbon, low-alloy steels. Nitriding is a heat treating process that diffuses nitrogen into the surface of a metal to create a case-hardened surface. Plasma nitriding can be further branched out into plasma nitrocarburising. 1.3 Advantages for utilizing plasma nitriding. Main Difference – Case Hardening vs Surface Hardening. These processes are most commonly used on high-carbon, low-alloy steels. Boriding vs. Nitriding – A Comparison Fatigue strength is increased mainly by the development of surface compressive stresses. Instead of bor, nitrogen is used to improve surface properties such as hardness and wear resistance. Quite often, selective gas nitriding or selective plasma-ion nitriding becomes necessary. Gas Nitriding And Plasma Ion Nitriding are case hardening processes. With recent advancements in pulse plasma nitriding, a new level of precision and control is possible which results in more uniform and consistent case hardening. Plasma nitriding is a smart choice whenever parts are required to have both nitrided and soft areas. In the last few decades, plasma nitriding, flame hardening, laser-hardening, and induction hardening methods have emerged as alternative methods for case-hardening of gears, with relatively small … Nitriding of steels produces less distortion and deformation than either carburizing or conventional hardening. Austenitic nitrocarburizing refers to the temperature of the nitrogen-enriched zone at the surface of a part. They are also used on medium and high-carbon steels, titanium, aluminium and molybdenum.In 2015, nitriding was used to generate unique duplex microstructure (Martensite-Austenite, Austenite … During plasma nitriding, in a vacuum at a temperature between 350 °C and 600 °C, in the presence of nitrogen and electric field, a plasma of accelerated atoms develops which collide against steel surface at a very high speed.A hard compound layer of nitrides is formed, followed by a diffusion layer and tough core. Ion (Plasma) Nitriding. Within that temperature range, nitrogen atoms can diffuse into the steel but the risk of distortion is decreased. The original Gas Nitride treatment is a “low temperature” furnace treatment with an atmosphere of Ammonia. Plasma (ionized gas) is the fourth material state. Case hardening refers to the “case” that develops around a part that is subjected to a hardening treatment. Selected area can be hardened on any sized place that are difficult with conventional heating and quenching, High surface hardness, improve resistance to wear and galling, improve fatigue life, improve corrosion resistance (stainless steel is an exception), Nitriding (Gas nitriding, liquid nitriding, plasma nitriding), Induction (Flame, magnetic, shell, electron-beam, laser), Ability to automate the system which gives good reproducibility of results, Ability to select the compound layer type to suit the required usage, Good friction, wear, and fatigue properties, High hardness of the treated surface, Flexibility to nitride stainless steels, titanium alloys, Possibility to lower nitriding temperature and to limit distortion, Gas composition (Ammonia, Nitrogen, Methane Hydrogen and Argon), Time (4 - 30 hrs depending on case depth). Ionitriding (Plasma), or Glow-Discharge Nitriding: It is a case-hardening process of enriching the surface of the steel with nascent nitrogen by glow discharge method. Plasma technology is primarily for stainless steel and other low alloy steels which are not suitable for a “standard” heat treatment processes. Quenching is not required for the production of a hard case. Material, part specs and intended uses dictate whether nitrocarburizing or carbonitriding is the best case hardening method. Plasma nitriding is a smart choice whenever parts are required to have both nitrided and soft areas. In this process, carbon together with nitrogen was introduced into the metal surface. Heat treatment is the use of heat to modify the properties of a material, especially in metallurgy.Heat treatment is done via heating and cooling of substances. There’s no theoretical limit to how deep a case can be achieved in either process, but a practical limit is how much time and resources one is willing to spend to achieve certain case depths. Material Recommended Core Hardness Plasma Nitrided Surface Hardness Total Case Depth (inches) 1020, 1045, Cast Iron: 14-8: File Hard 0.0005" 0.002-0.010 With recent advancements in pulse plasma nitriding, a new level of precision and control is possible which results in more uniform and consistent case hardening. Plasma nitriding is achieved using a D.C glow discharge technology, whereby the nitrogen gas inside the furnace is converted into nitrogen ions and absorbed by the metal. There are advantages and disadvantages to both processes. Nitrocarburizing also entails the dissolution of carbon and nitrogen into a workpiece, but, compared to carbonitriding, more nitrogen is used in nitrocarburizing. This process is carried out in the temperature range of 420 º C to 580 º C. … This provided a large amount of discharged energy, which causes the cathode and job part to glow. Nitrogen is commonly added to low carbon, low alloy steels that otherwise wouldn’t harden well as intended. Salt bath nitriding —also known as ferritic nitrocarburizing (FNC)— is one of the … Case depths as a result of nitrocarburizing are typically more shallow compared to carbonitriding. Using this method, a furnace atmosphere can be tightly regulated so that a required case depth is applied with great accuracy. Using this method, a furnace atmosphere can be tightly regulated so that a required case … There’s peace of mind in knowing what processes your parts will undergo, but only if you understand them. Nitriding is a case-hardening process of enriching the solid steel surface with nitrogen at a low temperature, normally in the range of 500-575°C (i.e., below A 1), when the steel is ferritic.. If you have questions about these or other heat treating processes, be sure to get in touch or read through our heat treating guide below: Nitriding is a popular case hardening technique renowned for the qualities it delivers at relatively low process temperatures. Unlike nitrocarburization, in nitriding only nitrogen is transferred. Salt bath…, Tool and die components are subjected to intense stresses before their final desired hardness is achieved. During industrial metal parts fabrication, manufacturers frequently seek to harden the exterior of steel work pieces to enhance wear resistance. ... (case hardening… Plasma Ion Nitriding is the most advanced case hardening process available. A phase change occurs in that zone, allowing the nitrogen to diffuse. The advantages of gaseous nitriding processes can be surpassed by plasma nitriding. Plasma ION nitriding is an industrial surface hardening treatment for iron-based materials. Thus, case hardening is achieved. Traditional Gas & Salt Bath Nitriding. Material, part specs and intended uses dictate whether nitrocarburizing or carbonitriding is the best case hardening method. Plasma nitriding imparts a hard wear resistant surface without brittleness, galling, or spalling. A plasma nitrided part is usually ready for use directly after treatment requiring no machining, polishing or any other post-nitriding finishing operations. The process concludes with a quench. This process is most useful for components such as Crankshafts, Gears and a multitude of other parts in tough environments (especially oil & gas, energy, aerospace, etc). For alloy steels containing strong nitride-forming elements. A typical plasma nitriding process is shown in Fig.3 and the processing parameters are detailed in Table 1. Together with the advantages of using only environmentally-friendly gases, plasma-based nitriding … Low-carbon, low-alloy steels with low hardenability are good candidates for carbonitriding because the process incorporates hardness to those materials that otherwise would not result from heat treating followed by quenching. Plasma nitriding is a similar process to plasma carburising, but with the use of a nitrogen-hydrogen gas mixture rather than a hydrocarbon to produce the glow discharge plasma. Nitriding. Ferritic nitrocarburizing is unique in that it offers case hardening without the need to heat metal parts into a phase change (it’s done at between 975 and 1,125 degrees Fahrenheit). Plasma Nitriding - the most advanced case-hardening technology today Nitriding in pulse glowing discharge (PLASMA nitriding) is an efficient method to increase hardness and wear-resistance of … The process temperature for Gas Nitriding … Plasma nitriding, known also as ion nitriding is a form of case hardening process. Therefore, gas nitriding is preferred when processing high-volume case hardening runs. Plasma nitriding. Here, we examine two case hardening techniques—nitrocarburizing and carbonitriding—and explain the differences between the techniques and the benefits that result from their use. All Rights Reserved. Parts to be nitrided are cleaned, … This nitrogen ion is then absorbed by the metal surface to harden it. Nitrocarburizing and carbonitriding sound somewhat similar and they perform similar functions: to make a workpiece surface harder by imparting carbon, nitrogen or both to its surface. The harden case, which is the nitriding layer is commonly known as ‘diffused case’ or ‘diffusion zone’. Less distortion compared to through hardening steel, Fatigue properties of a part can be controlled and frequently improved, Relatively inexpensive steel can be given wear-resisting properties which would be normally attained through the use of more highly alloyed and more expensive steels, Hardening of the surface of steels which cannot be normally capable of being hardened to a high degree by altering the surface composition, Combination of case and core properties can be attained that are not possible with conventional hardening treatment. The main difference is that in nitriding, nitrogen atoms are made to diffuse into the surface of the parts being processed, whereas in carburizing, carbon is used. There are two general types of nitriding processes: 1. The case hardening experts at Paulo have the tools and expertise to ensure your parts are up to spec and up to the job. The chemical changes brought on by case hardening are responsible for the added hardness of a part’s surface. Gas Nitriding is a thermo-chemical case hardening process. All too frequently we have to refuse requests to nitride unsuitable materials where no thought has been given to the possible distortion resulting from an alternative surface hardening process. It is the most technically superior of all nitriding processes and has many advantages compared to traditional salt bath and gas nitriding. There are three types of nitriding layer that could be formed during plasma nitriding treatment are featured in Fig.4. Gas Nitriding Gas nitriding is a case-hardening process whereby nitrogen is introduced into the surface of a solid ferrous alloy by holding the metal at a suitable temperature in contact with a nitrogenous gas, usually ammonia. The use of heat to modify the properties of a metal to create a case-hardened surface frequently... 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