Boriding vs. Nitriding – A Comparison Material, part specs and intended uses dictate whether nitrocarburizing or carbonitriding is the best case hardening method. 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. Unlike nitrocarburization, in nitriding only nitrogen is transferred. It is an extension of conventional nitriding process, utilizing plasma discharge physic to diffuse nitrogen into the surface of a ferrous alloy. Workpieces improved by nitrocarburizing include drive train components in automobiles and heavy equipment, firearm components like barrels and slides and dies for manufacturing processes. 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. Atomic nitrogen is then further converted into nitrogen ion through plasma ionization. The possibility of generating a compound layer free diffusion layer is often used in plasma nitriding prior to DLC coating. The original Gas Nitride treatment is a “low temperature” furnace treatment with an atmosphere of Ammonia. Plasma Nitriding or Ion Nitriding is a significant development of the original Nitriding process. The glow discharge at the surface of the steel part produces atomic nitrogen by ionisation of the ammonia gas. Main Difference – Case Hardening vs Surface Hardening. Quite often, selective gas nitriding or selective plasma-ion nitriding becomes necessary. Nitrogen is commonly added to low carbon, low alloy steels that otherwise wouldn’t harden well as intended. Material, part specs and intended uses dictate whether nitrocarburizing or carbonitriding is the best case hardening method. This provided a large amount of discharged energy, which causes the cathode and job part to glow. 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. All Rights Reserved. Thus, case hardening is achieved. Nitriding of steels produces less distortion and deformation than either carburizing or conventional hardening. Plasma nitriding is a smart choice whenever parts are required to have both nitrided and soft areas. Other, superficially cost-effective methods of enhancing surface hardness (or case hardness), involve much higher temperatures than nitriding. During carbonitriding, parts are heated in a sealed chamber well into the austenitic range—around 1600 degrees Fahrenheit—before nitrogen and carbon are added. Case hardening refers to the “case” that develops around a part that is subjected to a hardening treatment. Nitriding is a popular case hardening technique renowned for the qualities it delivers at relatively low process temperatures. The chemical changes brought on by case hardening are responsible for the added hardness of a part’s surface. 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. There are two general types of nitriding processes: 1. Ion (Plasma) Nitriding. Together with the advantages of using only environmentally-friendly gases, plasma-based nitriding … Nitrogen reacts with the iron and other alloys on the surface, forming strong nitrides that protect the surface of the material. Our process is also very clean and environmentally friendly. NITRIDING Nitriding is a heat treating process that diffuses nitrogen into the surface of a metal to create a case hardened surface. Gas Nitriding And Plasma Ion Nitriding are case hardening processes. Using this method, a furnace atmosphere can be tightly regulated so that a required case … Carbonitriding typically achieves greater case depths compared to nitrocarburizing. Fig.1 shows a schematic of the plasma nitriding process. MPT uses a pulsed plasma nitriding system Here at MPT in Valencia California, our process is unique compared to other case hardening methods. To put it simply, plasma nitriding utilizes a Direct Current electricity source to break up nitrogen gas (N2) into nitrogen ion (N+). 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. 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. Within that temperature range, nitrogen atoms can diffuse into the steel but the risk of distortion is decreased. Can be applied to very large parts, which due to very large mass or because of danger of cracking would be impractical to harden, by conventional heating and quenching. Gas nitriding is arguably the more versatile case hardening option. 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 process is carried out in the temperature range of 420 º C to 580 º C. … 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. Nitriding. Austenitic nitrocarburizing refers to the temperature of the nitrogen-enriched zone at the surface of a part. The details are summarized in Tables 2 and 3. 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. Plasma nitriding/Ion nitriding Nitrocarburising Gas nitriding Ferritic nitrocarburising ... Gas nitriding is a thermochemical case hardening process used to increase wear resistance, surface hardness and fatigue life by dissolution of nitrogen and hard nitride … Plasma Nitriding uses glow discharge technology to introduce elemental nitrogen to the surface of parts for subsequent diffusion. Plasma Nitriding. Parts to be nitrided are cleaned, … During the plasma nitriding process, the job part and the cathode inside the furnace will be emitting a purple glow. 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. Plasma nitriding can be further branched out into plasma nitrocarburising. There are advantages and disadvantages to both processes. This is because voltages had dropped sharply at these regions. A typical plasma nitriding process is shown in Fig.3 and the processing parameters are detailed in Table 1. Traditional Gas & Salt Bath Nitriding. 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. Main Difference – Carburizing vs Nitriding. 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. This eliminates costly cleaning or grinding to remove the brittle white layer associated with traditional nitriding. There are two forms of nitrocarburizing: austenitic and ferritic. 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. In Micropuls® plasma nitriding, we use the processes of PLASNIT® and … The chemical changes brought on by case hardening are responsible for the added hardness of a part’s surface. About Nitriding. 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. These processes are most commonly used on high-carbon, low-alloy steels. Plasma nitriding. Then nitrogen atoms incorporate into the surface of the metal, cleaning the surface and diffusing into the metal. The harden case, which is the nitriding layer is commonly known as ‘diffused case’ or ‘diffusion zone’. NITRIDING These processes are most commonly used on low-carbon, low-alloy steels. 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 … Nitrocarburizing also entails the dissolution of carbon and nitrogen into a workpiece, but, compared to carbonitriding, more nitrogen is used in nitrocarburizing. Case depths as a result of nitrocarburizing are typically more shallow compared to carbonitriding. Nitriding is a lengthy process and, depending on the case depth requirements, may take 4 to 60 hours or more. The case hardening experts at Paulo have the tools and expertise to ensure your parts are up to spec and up to the job. Plasma technology is primarily for stainless steel and other low alloy steels which are not suitable for a “standard” heat treatment processes. Quality Plasma (Ion) Nitriding Equipment for excellent process control, repeatable results and case-hardening that suits your needs. 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.. In this process, carbon together with nitrogen was introduced into the metal surface. Plasma nitriding is a smart choice whenever parts are required to have both nitrided and soft areas. 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. Plasma Nitriding. Fatigue strength is increased mainly by the development of surface compressive stresses. Our plasma nitriding hardness chart will help you identify the materials & typical results achieved when considering nitriding. Fatigue strength is increased mainly by the development of surface compressive stresses. The carbonitriding process usually takes a few hours achieve the desired results: a part with high surface hardness but with a relatively ductile core. Adding nitrogen also helps a part maintain hardness during use in high-heat settings. Nitriding is a heat treating process that diffuses nitrogen into the surface of a metal to create a case-hardened surface. Plasma nitriding, known also as ion nitriding is a form of case hardening process. The Nitriding process is an established and successful means of generating a hard case on a component. The advantages of gaseous nitriding processes can be surpassed by plasma nitriding. The process makes parts more resistant to wear and increases fatigue strength. Plasma nitriding, known also as ion nitriding is a form of case hardening process. 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 allows the efficient nitriding of stainless steels at low temperatures with the aim of a hardened case while maintaining corrosion resistance by creating so-called expanded austenite or expanded martensite (see gaseous nitriding, Section 3.7.3). Due to their shape and size, carbon atoms cannot diffuse into the part in this low-temperature process. Also called “surface hardening”, this case hardening process typically relies upon thermochemical processes to transform the outer layer of a … The glow layer surrounding the job part is formed by these positive ions. 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. The nitrogen comes in the form of ammonia, which cracks on the surface of the part to provide nitrogen that diffuses into the steel. Because the part is heated into the austenitic range, a phase change occurs and carbon and nitrogen atoms can diffuse into the part. A plasma nitrided part is usually ready for use directly after treatment requiring no machining, polishing or any other post-nitriding finishing operations. Parts to be nitrided are cleaned, degreased and are then charged in the vessel, which is then evacuated to … 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 Plasma (ionized gas) is the fourth material state. Instead of bor, nitrogen is used to improve surface properties such as hardness and wear resistance. Nitriding is a case hardening process in which the surface nitrogen concentration of a ferrous is increased by diffusion from the surrounding environment to create case-hardened surface. Plasma nitriding imparts a hard wear resistant surface without brittleness, galling, or spalling. It is an extension of conventional nitriding process, utilizing plasma discharge physic to diffuse nitrogen into the surface of a ferrous alloy. There are three types of nitriding layer that could be formed during plasma nitriding treatment are featured in Fig.4. The nitriding processes give the surface hardness and a distinct microstructure. Salt bath…, Tool and die components are subjected to intense stresses before their final desired hardness is achieved. Ferritic nitrocarburizing is conducted at a lower temperature where no phase change occurs. Plasma nitriding can be further branched out into plasma nitrocarburising. 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 Ion Nitriding is the most advanced case hardening process available. +0.4 -0.5 effective case depth 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. 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. The nitrogen ion, N+, will then diffuse into the metal surface as finely dispersed nitrides, imparting high hardness to the surface. Plasma vs Gas Advantages of Plasma Nitriding Vs. This case hardening process is also termed as plasma ion nitriding or ion nitriding or glow-discharge nitriding. It’s easy to get lost in the chemistry—and the nomenclature—behind heat-treating processes. Nitriding is another thermochemical heat treating process. Gas nitriding is arguably the more versatile case hardening option. The process temperature for Gas Nitriding … 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 … 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. Together with the advantages of using only environmentally-friendly gases, plasma-based nitriding has become a focal point for additional innovations, and a requirement for those that seek a safer, more eco-friendly solution. ... (case hardening… 7. 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. It is the latest advancement in Nitriding Technology. Plasma nitriding is environmentally safe and can ease or eliminate the above problems, and furthermore, plasma nitriding can effectively overcome the surface oxide problem encountered in traditional nitriding processes for stainless steels. 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. Quenching is not required for the production of a hard case. 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. A phase change occurs in that zone, allowing the nitrogen to diffuse. During industrial metal parts fabrication, manufacturers frequently seek to harden the exterior of steel work pieces to enhance wear resistance. Nitrocarburizing is much quicker and takes 0.5 to 6 hours. They improve wear resistance, seizing resistance, corrosion resistance and fatigue life of nitrided parts. Inside our heated furnaces, nitrogen atoms accelerate towards the metal parts. Particularly when applied to higher alloyed steels, plasma nitriding imparts a high surface hardness which promotes high resistance to wear, scuffing, galling and seizure. This nitrogen ion is then absorbed by the metal surface to harden it. / Services / Nitriding and Nitrocarburizing / Ion (Plasma) Nitriding High-density radio-frequency and direct current (RF/DC) plasma nitriding process was applied to synthesize the nitrided AISI304 microstructure and to describe the essential … 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). Plasma nitriding can also clean the surface by sputtering. 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 … Heat treatment is the use of heat to modify the properties of a material, especially in metallurgy. 1.3 Advantages for utilizing plasma nitriding. Plasma ION nitriding is an industrial surface hardening treatment for iron-based materials. Copyright © 2006 TPP Information Centre. Case hardening refers to the “case” that develops around a part that is subjected to a hardening treatment. 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. Fig.2 shows a job part undergoing plasma nitriding treatment. The process concludes with a quench. Gas Nitriding is a thermo-chemical case 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’s peace of mind in knowing what processes your parts will undergo, but only if you understand them. Plasma Nitriding, also called Ion Nitriding, is a thermo-physical case hardening process. Though wrapped in a bit of “alchemi-cal mystery,” it remains the simplest of the case hardening techniques. Nitrocarburizing decreases the potential for corrosion in parts and enhances their appearance. Why Choose Nitrocarburization Over Other Processes? 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. The process generally takes only a few hours. 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. For alloy steels containing strong nitride-forming elements. Salt bath nitriding —also known as ferritic nitrocarburizing (FNC)— is one of the … Plasma nitriding is environmentally safe and can ease or eliminate the above problems, and furthermore, ... (case hardening). Nitriding and carburizing are the two most common heat treatment practices for surface hardening functional components. 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. A more modern development of the nitriding process, also known as ion nitriding.In this process the component is made cathodic in relation to the furnace shell and ammonia gas is fed into the evacuated chamber. Using this method, a furnace atmosphere can be tightly regulated so that a required case depth is applied with great accuracy. Ion Nitriding vs Gas Nitriding: ... (plasma) nitriding are often compared when engineers decide what is best for their application. Molecular nitrogen is first broken into atomic nitrogen through direct plasma dissociation. However, the nitriding process takes tens to hundreds of times longer than nitrocarburization to achieve the same case depth. Therefore, gas nitriding is preferred when processing high-volume case hardening runs. A low temperature plasma nitriding process has become one of the most promising methods to make solid-solution hardening by the nitrogen super-saturation, being free from toxicity and energy consumption. Carbonitriding is used to harden surfaces of parts made of relatively cheaper and easily-machined steels, like stamped automotive parts or wood screws. 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). Because the process is computer controlled, we can simultaneously manage multiple variables such as temperature, gas mixtures, amperage, and voltage to control depth of penetration and required material hardness. However, even though cyanide baths require aging and special mixes, they do apply deeper case depths.