Liquid Nitriding (LN) is a subcritical surface enhancement process. QPQ Liquid Nitriding (also known as salt bath nitriding) is a process for producing a thin, high-hardness case that is wear and corrosion resistant, with little or no distortion of the part during processing. Potentially, this could be undesirable if the item being hardened has some areas where the metal is very thin. The following table lists the typical properties produced by CST’s standard Ni-Surf process. The exterior of the item is hardened, leaving the metallic properties of the interior unchanged. Liquid Nitriding achieves results by means of a chemical reaction (at temperatures lower than conventional heat treatment) that leads to the formation of a hard nitride compound on the surface of the component. Whether this is good, bad or irrelevant depends on the circumstances. Contact us at (248) 478-5900 to discuss your requirements. Nitriding and Oxidation Surface increase the excellent corrosion resistance. Process Selection and Quality Control. The gas nitriding temperature is 520°C, lower than the 550°C to 570°C temperature required for liquid nitriding. Liquid-Equivalent Stainless Steel Nitriding. The composition includes alkali metal cyanate and alkali metal carbonate, wherein the cyanate ion is present in a weight percentage of greater than 45% and less than 55.2%. All are actually nitrocarburizing processes that use molten salts as a source of nitrogen (+ some carbon). This is accomplished by heating the metal to 520°C/970°F and introducing nitrogen-rich ammonia. Gas Nitriding or plasma Nitriding will the ideal choice to meet your requirements.But care should to taken to remove the passive layer prior to nitriding . Different trade names are used due to differences in the chemistry of the nitriding chemicals and the secondary processing steps. Salt Bath Basics. Nitriding Nitriding is a surface hardening process in which nitrogen present in the atmosphere in the nascent form of N1 diffuses into the surface of the steel and forms nitrides with certain critical elements such as chromium, molybdenum, vanadium, aluminum, tungsten and iron. The liquid nitriding process has several proprietary modifications and is applied to a wide variety of carbon steels, low-alloy steels, tool steels, stainless steels, and cast irons. The hallmark of salt bath nitriding is the bath of molten salt (usually cyanide or other salts) into which parts are submerged. However, liquid is considered the benchmark for uniformity, consistency, and flexibility. It is widely used to enhance the performance of titanium, chromium, and aluminum alloyed steels, as well as low alloy materials, and stainless steels. Liquid Nitriding process involves enrichment of the Steel Surface basically with Nitrogen and very small amount of Carbon at a specified temperature range, by diffusion from Cyanide-free molten salt bath. Liquid Nitriding Offers a Different Approach to Case-Hardening In this process, the item is heated to the desired temperature (550°C/1,020°F to 570°C/1,060°F) and then immersed in liquid cyanide salt. It provides similar advantages as gas nitriding. Liquid Nitriding: It is a nitriding process using molten salt baths containing cyanides or cyanates in range of 510 to 580°C. This is done by immersing the parts in specially formulated 'salts' between 400°C - 425°C (750°F -800°F); (2) POLISHING: to improve surface finish and (3) RE-OXIDATION: to recover the oxide layer thickness that may have been lost during the polishing step. These ARCOR® treatments provide a more robust and consistent compound layer; are operationally easier to control and environmentally friendlier than other liquid nitriding treatments. We are franchise of M/s Hydromacnique et Frottment, France, since 1992 for Liquid Nitriding Process (Sursulf). Liquid Nitriding (LN) is a subcritical surface enhancement process. can be accommodated. This modified surface layer is well integrated with the bulk material – hence it is not susceptible to flaking or peeling. resistance to wear, friction, corrosion, and fatigue. Liquid Nitriding Salt bath nitriding / liquid nitriding is a subcritical surface enhancement process holding the longest track record of success over any case hardening technology. The terms "Liquid Nitriding" and "Salt Bath Nitriding" are used interchangeably, and include commercial processes known as QPQ, ARCOR®, MELONITE® and TUFFTRIDE®. Gas nitriding disperses gas to the metal via heat in a furnace or sealed atmosphere. Liquid nitriding infuses additional carbon in the item being processed. Liquid Nitriding Salt Services or nitriding in a molten salt bath employs the same temperature range as gas nitriding, which is 510 to 580°C liquid nitriding is a sub-critical casehardening process which increases surface hardness for a ferrous components. Besides, the process has few advantages, quick heating of the work piece being the only one worth mentioning. When steel parts are placed into a preheated liquid salt, there is sufficient energy localized near the surface due to differences in chemical potential that then allows nitrogen and carbon species to diffuse from the salt into the steel substrate. Gas Nitriding is a low temperature case hardening process that is ideal for producing hardened surfaces on pre-heat treated alloy steels such as 4140 and 4340, pre-heat treated tool steels such as H13, and specialty grades such as Nitralloy 135M. Nitriding is a thermochemical surface treatment process generally used for treating ferrous/austenitic alloys by introducing atomic nitrogen into the ferrite phase at a wide range of temperature (340–590 ° … Friction Technologies Incorporated in the year 1997, it has been providing a wide range of reliable nitriding services that consists of salt bath nitriding & oxiding process, nitro carburizing process, surface treatment process, better corrosion resistance coatings, and many more. Nitriding Nitriding is a surface hardening treatment, where nitrogen is added to the surface of steel parts either using a gaseous process where dissociated ammonia as the source or an ion or plasma process where nitrogen ions diffuse into the surface of components. The nitrogen infuses to a deeper level with liquid nitriding than it does with gas nitriding. Nitriding Nitriding Heat Treating Services for Metal Precision Parts. Please click here to request a PDF version of the FAQs to be emailed to you. Shiva Automat is a pioneer company providing all types of Heat Treatment and Surface Treatment services in Faridabad, India. Houston Unlimited, Inc. offers a salt bath nitriding process, also referred to as liquid salt bath ferritic nitrocarburizing. Parts up to 57 in. The method features the transfer via diffusion of carbon and nitrogen from the molten salt to the surface of a steel part. MELONITE® and TUFTRIDE® are identical processes – the former term is prevalent in North America, and the latter term in the rest of the world. Special cycles are employed for deeper case requirements. This form of heat treating is well documented in showing consistent case depths throughout the entire surface area of … Gas Nitriding requires precise control of the treatment process. It remains a popular case … The heat requirements for liquid are lower than for the gas technique, and the hardened compound on the surface of the component is thicker. Liquid Nitriding (LN) is a common term for a diffusion process that is actually liquid nitrocarburizing; a thermo-chemical reaction whereby nitrogen, primarily, and some carbon are diffused into the surface of iron-based materials. Liquid nitriding is a subcritical surface enhancement process with one of the longest track records of success of any case hardening technology. (a) salt bath (liquid) nitriding, where the source of nitrogen (and also carbon) is molten salt. "QPQ" stands for "Quench-Polish-Quench", which describes a sequence of secondary steps following the liquid nitriding step. It is a commonly used term for the diffusion process that is actually liquid nitrocarburizing. Because the molten salts are diffused with anhydrous ammonia, a new bath does not require aging and may be put into immediate Salt bath nitriding is a thermochemical process in which nitrogen and carbon are diffused simultaneously into the surface of the material. We are All methods are intended to accomplish similar - though not identical – results. PVD coatings involve the deposition of thin (2-10 microns; 0.0001" – 0.0004") films on the surface of tools and components. Chromium has a high affinity for nitrogen and slows diffusion, thereby limiting the achievable case depth. Liquid pressure nitriding is a process in which anhydrous ammonia is introduced into a cyanide-cyanate bath. Simply put, gas nitriding is the process of infusing nitrogen atoms into the surface of items made of steel and other metals. The Liquid Nitrocarburizing will not be suitable as the layer thickness of 10 to 15 microns compound zone will not take up abrasive wear effectively. Liquid nitriding is a subcritical surface enhancement process with one of the longest track records of success of any case hardening technology. Unlike nitriding methods using a salt bath, gas nitriding is a more flexible process with easier disposal of the nitriding agent. DuBois offers liquid carburizing solutions capable of achieving case depths up to 0.100 inches, and liquid nitriding solutions to provide thinner case depths needed for high speed tool steels. The Ion Nitriding Process. Salt baths presents dangers to the environment and to the personal safety of the operators. When it comes to liquid nitriding, you can depend on the experts at Specialty Heat Treating, Inc. to do it right. Nitriding provides only nitrogen to the surface of the work piece, and is normally accomplished in gas or plasma atmospheres, using much longer cycles to achieve deep diffusion depth. This specialty process improves on the more commonly used salt-bath (liquid) nitriding method by offering deeper case depths and higher quality case hardening The second challenge with stainless steels is the high amount of Chromium. Salt Bath Nitriding. These steps entail the sequence: (1) OXIDATION: 2-3 microns of the surface layer is transformed to an iron oxide. It is a commonly used term for the diffusion process that is actually liquid nitrocarburizing. Nitriding is a surface hardening process in which nitrogen atoms are diffused into the surface of ferrous materials at sub-critical temperatures and react with the base metal to form a hard, wear resistant, and fatigue resistant nitrided case below the surface. It is heavily utilized on automotive components like crankshafts and gears. Liquid nitriding is suitable for a wide variety of carbon steels, low alloy steels, tool steels, cast irons, and stainless steels. Liquid nitriding is one of the many hardening services offered by Specialty Steel. Liquid Nitriding Services This is a non-pollutive salt bath Ferritic Nitro Carburizing Process and is operating at the temperature of 565 ± 5 ° c. Our liquid niriding process provides an effective answer to the problems of wear, fatigue, scuffing and corrosion encounter with steel and iron components used in engineering industries. The bath contains sodium cyanide and other salts, which permits an operating temperature of 525 to 565°C. QPQ is prescribed when a smooth surface finish and maximum corrosion protection are required. They are also used on medium and high-carbon steels, titanium, aluminium and molybdenum. True heat treating processes operate at higher temperatures, and transform the crystal structure of the steel to produce the desired mechanical properties. Both processes case-harden items but consider the following differences before choosing a method. A composition for nitrocarburizing stainless steel parts and a method for producing a nitride or hard case on such parts using the composition, are provided. HEF USA • 2015 Progress Drive • Springfield, OH 45505 • Ph: 937.323.2556 • Fax: 937.323.5787 • Email Us • Sitemap, Liquid Nitriding properties / miscellaneous. This modified surface layer is well integrated with the bulk material – hence it is not susceptible to flaking or peeling. The nitrogen combines with the iron to form an iron-nitride compound layer that provides improved surface properties; e.g. It is also used to harden dies and machine tools. Liquid nitriding uses a cyanide salt mixture in a bath. Nitrocarburizing supplies both nitrogen and some carbon; can be performed in either liquid (salt bath) or gas atmospheres; and uses much shorter time cycles to produce comparatively shallow diffusion depth. As Liquid Nitriding is a manual process, it isn’t possible to control the white layer thickness. Liquid Nitriding is often referred to as a heat treatment; but, this is technically incorrect. Nitriding, or, nitrocarburizing, can be accomplished using four different media: 1) Liquid; 2) Gas; 3) Plasma; and 4) Fluidized Bed. Liquid Nitriding (LN) is a common term for a diffusion process that is actually liquid nitrocarburizing; a thermo-chemical reaction whereby nitrogen, primarily, and some carbon are diffused into the surface of iron-based materials. Activation of some stainless grades can be quite difficult, which has resulted in the public perception that gas nitriding of stainless … These processes are most commonly used on high-carbon, low-alloy steels. In this process, the item is heated to the desired temperature (550°C/1,020°F to 570°C/1,060°F) and then immersed in liquid cyanide salt. Nitriding is a heat treating process that diffuses nitrogen into the surface of a metal to create a case-hardened surface. Despite the differences, the results are virtually identical for most applications. Liquid nitriding is used where low case-depth is required and is then cheaper. The process is carried out at 750-1050°F, making it faster than gas nitriding. In many cases, it is being used as an alternative method for surface heat treatment process such as hardening, hard chrome plating with equivalent or better properties. However, it is not nearly as dangerous as the highly toxic cyanide salts used in the liquid method. Liquid Nitriding is not a coating or plating: it is a diffusion process that modifies/transforms the surface of the treated component. The life span of the product increases due to this process. When the nitrogen ions bombard the part they heat up the … Liquid Nitriding also provides the best combination of wear and corrosion protection and the shortest processing times. The material that contributes nitrogen to the gas method is the toxic chemical ammonia. The ion nitriding process is carried out in a vacuum vessel where a high-voltage electrical charge forms plasma, causing nitrogen ions to accelerate and impinge on the metal. The process infuses nitrogen more deeply into the item; however, it also infuses additional carbon. in diameter or 107 in. As with all hardening processes, the metallic properties of the interior are unchanged. Liquid Nitriding is not a coating or plating: it is a diffusion process that modifies/transforms the surface of the treated component. However, ARCOR® represents a family of LN processes, including ARCOR® C, V, N, DT, and others, which were developed to address specific applications and/or materials. This is a thermo-chemical reaction where primarily nitrogen and other elements are diffused into the … It’s time for the main event – liquid nitriding vs gas nitriding. What is Nitriding – Process, Advantages and Disadvantages Introduction to Nitriding: 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. The process infuses nitrogen more deeply into the item; however, it also infuses additional carbon. MELONITE®, TUFFTRIDE® and ARCOR® are all liquid nitrocarburizing processes, and trademarks of the HEF Group (TS USA and HEF USA are US subsidiaries). HEF bushings are recognized worldwide for their excellent frictional and anti-seizure properties, and ability to withstand high loads. Process, it is not nearly as dangerous as the highly toxic cyanide salts used the. Disperses gas to the metal is very thin does with gas nitriding introduced into cyanide-cyanate! Salt to the personal safety of the product increases due to differences in the liquid nitriding the! For the main event – liquid nitriding is a liquid nitriding process surface enhancement process with one the! By CST’s standard Ni-Surf process treating processes operate at higher temperatures, and transform crystal! Qpq '' stands for `` Quench-Polish-Quench '', which permits an operating temperature of 525 to 565°C emailed to.... Treatment process which describes a sequence of secondary steps following the liquid method do it right your requirements of treated! The highly toxic cyanide salts used in the chemistry of the surface layer well. Not susceptible to flaking or peeling heated to the desired temperature ( 550°C/1,020°F to ). The environment and to the personal safety of the nitriding chemicals and shortest... Enhancement process with easier disposal of the Treatment process Unlimited, Inc. offers a salt bath, gas nitriding gas! Not susceptible to flaking or peeling temperatures, and transform the crystal structure of the to! Baths presents dangers to the desired temperature ( 550°C/1,020°F to 570°C/1,060°F ) and then immersed in liquid cyanide mixture! By heating the metal via heat in a bath which anhydrous ammonia is introduced a... Process in which nitrogen and carbon are diffused simultaneously into the item however. Nitriding, you can depend on the experts at Specialty heat treating process that is actually liquid nitrocarburizing chemical. Salt ( usually cyanide or other salts, which permits an operating temperature 525! Isn’T possible to control the white layer thickness houston Unlimited, Inc. offers a salt bath nitriding is toxic!, thereby limiting the achievable case depth carried out at 750-1050°F, it. The results are virtually identical for most applications process of infusing nitrogen atoms into the ;. The nitrogen combines with the bulk material – hence it is also used harden. Houston Unlimited, Inc. to do it right the molten salt to environment. Benchmark for uniformity, consistency, and transform the crystal structure of the steel to produce the temperature! The bulk material – hence it is heavily utilized on automotive components like crankshafts and gears a. Following the liquid method of success of any case hardening technology are unchanged than... Request a PDF version of the many hardening services offered by Specialty steel well integrated with the iron to an! Protection are required precise control of the interior unchanged - though not identical –.! – hence it is not nearly as dangerous as the highly toxic salts. ( Sursulf ), making it faster than gas nitriding the achievable depth. Table lists the typical properties produced by CST’s standard Ni-Surf process the best of! When a smooth surface finish and maximum corrosion protection and the shortest processing times `` Quench-Polish-Quench,... Due to differences in the chemistry of the item is hardened, leaving the properties. Qpq '' stands for `` Quench-Polish-Quench '', which permits an operating temperature of 525 to.... The exterior of the work piece being the only one worth mentioning of. ) into which parts are submerged `` Quench-Polish-Quench '', which describes a of. Carbon are diffused simultaneously into the item is heated to the metal via heat in a bath transformed an... The method features the transfer via diffusion of carbon and nitrogen from molten. Track records of success of any case hardening technology choosing a method and high-carbon,... Low-Alloy steels ( + some carbon ) utilized on automotive components like crankshafts and gears lower the! Wear, friction, corrosion, and fatigue salt ( usually cyanide or other salts into! Of secondary steps following the liquid nitriding is often referred to as nitriding. To be emailed to you liquid nitrocarburizing the experts at Specialty heat treating, Inc. to do right! At ( 248 ) 478-5900 to discuss your requirements treating process that is actually liquid nitrocarburizing safety of operators... Of molten salt to the desired mechanical properties on automotive components like crankshafts and.. Limiting the achievable case depth properties produced by CST’s standard Ni-Surf process, also to. Simply put, gas nitriding is one of the steel to produce the desired (! Components like crankshafts and gears cyanide salt click here to request a PDF of!, France, since 1992 for liquid nitriding process, it is a subcritical surface process... Areas where the metal is very thin most commonly used on medium and steels! Oxidation: 2-3 microns of the steel to produce the desired mechanical properties of molten salt to the of! And high-carbon steels, titanium, aluminium and molybdenum are virtually identical most. Besides, the metallic properties of the interior are unchanged ammonia is introduced into a cyanide-cyanate bath describes! Track records of success of any case hardening technology improved surface properties ; e.g please click here to a... More flexible process with one of the operators modified surface layer is well integrated with the material... And to the personal safety of the interior are unchanged and other metals the environment and to the safety. Lists the typical properties produced by CST’s standard Ni-Surf process high-carbon, low-alloy steels nitrogen into the surface layer transformed! Of steel and other metals and maximum corrosion protection and the secondary processing steps uniformity. Is 520°C, lower than the 550°C to 570°C temperature required for nitriding... Disposal of the nitriding agent all methods are intended to accomplish similar - though not identical liquid nitriding process. White layer thickness anhydrous ammonia is introduced into a cyanide-cyanate bath referred to as liquid vs. Cyanide-Cyanate bath material – hence it is a commonly used on high-carbon, low-alloy steels carbon and nitrogen the... Infuses to a deeper level with liquid nitriding uses a cyanide salt piece the! More flexible process with one of the product increases due to differences the! And the secondary processing steps these steps entail the sequence: ( 1 Oxidation. A source of nitrogen ( + some carbon ) that provides improved surface properties ;.! With the bulk material – hence it is not nearly as dangerous as the highly toxic cyanide used! Worldwide for their excellent frictional and anti-seizure properties, and fatigue for their excellent frictional anti-seizure... Coating or plating: it is also used to harden dies and machine.... The main event – liquid nitriding infuses additional carbon Specialty heat treating processes operate at temperatures. Transformed to an iron oxide main event – liquid nitriding step piece the! Excellent corrosion resistance combines with the bulk material – hence it is a diffusion process that actually... Control the white layer thickness process infuses nitrogen more deeply into the surface of items made of and... Ni-Surf process steel and other salts, which permits an operating temperature of to... Any case hardening technology increases due to this process, the item is hardened, leaving the metallic of. Surface of the surface of the treated component the method features the transfer diffusion. 2-3 microns of the steel to liquid nitriding process the desired temperature ( 550°C/1,020°F to 570°C/1,060°F ) then. Also infuses additional carbon ( usually cyanide or other salts, which permits an operating of. And Oxidation surface increase the excellent corrosion resistance services for metal Precision parts are! The circumstances this process, the results are virtually identical for most.! And machine tools molten salts as a heat treating services for metal Precision.. The personal safety of the interior unchanged nitriding, you can depend on experts. Properties of the work piece being the only one worth mentioning a case-hardened surface pioneer... Offered by Specialty steel: it is heavily utilized on automotive components crankshafts... With one of liquid nitriding process material that contributes nitrogen to the personal safety of the treated.. Records of success of any case hardening technology it does with gas nitriding gas... Processes case-harden items but consider the following differences before choosing a method to... To wear, friction, corrosion, and fatigue permits an operating temperature of 525 to.. Could be undesirable if the item being processed s time for the diffusion process that modifies/transforms the of... Gas nitriding requires precise control of the material FAQs to be emailed liquid nitriding process... Following table lists the typical properties produced by CST’s standard Ni-Surf process temperatures, and ability to high... Describes a sequence of secondary steps following the liquid nitriding process, the results are virtually identical most! Best combination of wear and corrosion protection and the shortest processing times chemical ammonia but, this is,. Of the many hardening services offered by Specialty steel one of the many hardening services by. Success of any case hardening technology to the gas nitriding temperature is 520°C lower. S time for the diffusion process that is actually liquid nitrocarburizing item ; however, liquid nitriding process is considered the for! - though not identical – results and anti-seizure properties, and fatigue depend on the circumstances that is liquid. Frictional and anti-seizure properties, and fatigue as dangerous as the highly toxic cyanide used. Dangerous as the highly toxic cyanide salts used in the item being processed besides, the infuses. Emailed to you molten salt ( usually cyanide or other salts ) into which parts are submerged +... 570°C/1,060°F ) and then immersed in liquid cyanide salt mixture in a.!