This process is carried out in the temperature range of 420 º C to 580 º C. … 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. 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. Nitriding and carburizing are the two most common heat treatment practices for surface hardening functional components. 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. Plasma nitriding imparts a hard wear resistant surface without brittleness, galling, or spalling. Nitriding is a heat treating process that diffuses nitrogen into the surface of a metal to create a case-hardened 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. Plasma Nitriding or Ion Nitriding is a significant development of the original Nitriding process. 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. 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). Though wrapped in a bit of “alchemi-cal mystery,” it remains the simplest of the case hardening techniques. There’s peace of mind in knowing what processes your parts will undergo, but only if you understand them. Ion Nitriding vs Gas Nitriding: ... (plasma) nitriding are often compared when engineers decide what is best for their application. Nitrogen reacts with the iron and other alloys on the surface, forming strong nitrides that protect the surface of the material. NITRIDING These processes are most commonly used on low-carbon, low-alloy steels. 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). Adding nitrogen also helps a part maintain hardness during use in high-heat settings. 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. The advantages of gaseous nitriding processes can be surpassed by plasma nitriding. 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. 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). Nitrocarburizing also entails the dissolution of carbon and nitrogen into a workpiece, but, compared to carbonitriding, more nitrogen is used in nitrocarburizing. Plasma Nitriding uses glow discharge technology to introduce elemental nitrogen to the surface of parts for subsequent diffusion. Plasma Ion Nitriding is the most advanced case hardening process available. Material, part specs and intended uses dictate whether nitrocarburizing or carbonitriding is the best case hardening method. 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 … Quite often, selective gas nitriding or selective plasma-ion nitriding becomes necessary. The nitriding processes give the surface hardness and a distinct microstructure. During the plasma nitriding process, the job part and the cathode inside the furnace will be emitting a purple glow. Plasma nitriding can be further branched out into plasma nitrocarburising. Fatigue strength is increased mainly by the development of surface compressive stresses. Salt bath nitriding —also known as ferritic nitrocarburizing (FNC)— is one of the … There are three types of nitriding layer that could be formed during plasma nitriding treatment are featured in Fig.4. Our plasma nitriding hardness chart will help you identify the materials & typical results achieved when considering nitriding. Plasma Nitriding. The chemical changes brought on by case hardening are responsible for the added hardness of a part’s surface. Then nitrogen atoms incorporate into the surface of the metal, cleaning the surface and diffusing into the metal. 7. The process concludes with a quench. A typical plasma nitriding process is shown in Fig.3 and the processing parameters are detailed in Table 1. 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.. Case depths as a result of nitrocarburizing are typically more shallow compared to carbonitriding. Atomic nitrogen is then further converted into nitrogen ion through plasma ionization. Nitrogen is commonly added to low carbon, low alloy steels that otherwise wouldn’t harden well as intended. The process temperature for Gas Nitriding … Unlike nitrocarburization, in nitriding only nitrogen is transferred. Nitriding is a lengthy process and, depending on the case depth requirements, may take 4 to 60 hours or more. Main Difference – Carburizing vs 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. Using this method, a furnace atmosphere can be tightly regulated so that a required case depth is applied with great accuracy. Fig.1 shows a schematic of the plasma nitriding process. Material, part specs and intended uses dictate whether nitrocarburizing or carbonitriding is the best case hardening method. Plasma technology is primarily for stainless steel and other low alloy steels which are not suitable for a “standard” heat treatment processes. Boriding vs. Nitriding – A Comparison The nitrogen comes in the form of ammonia, which cracks on the surface of the part to provide nitrogen that diffuses into the steel. Plasma nitriding, known also as ion nitriding is a form of case hardening process. 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. 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. The original Gas Nitride treatment is a “low temperature” furnace treatment with an atmosphere of Ammonia. The glow discharge at the surface of the steel part produces atomic nitrogen by ionisation of the ammonia gas. Other, superficially cost-effective methods of enhancing surface hardness (or case hardness), involve much higher temperatures than nitriding. They improve wear resistance, seizing resistance, corrosion resistance and fatigue life of nitrided parts. For alloy steels containing strong nitride-forming elements. Plasma nitriding can be further branched out into plasma nitrocarburising. Therefore, gas nitriding is preferred when processing high-volume case hardening runs. 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. Plasma (ionized gas) is the fourth material state. Plasma Nitriding. 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. About Nitriding. 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. 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. 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