Modern salt-bath plant Nitrocarburizing offers an alternative to complicated coating processes and enables manufacturers to replace expensive materials with less costly ones. Common applications include spindles, cams, gears, dies, hydraulic piston rods, and powdered metal components. The compound layer consists of iron, nitrogen, and oxygen, is abrasion resistant, and stable at elevated temperatures. The shared attributes of this class of this process is the introduction of nitrogen and carbon in the ferritic state of the material. Ferritic nitrocarburizing solves some of the problems of size change and distortion that are seen in higher temperature treatments. The processing temperature ranges from 525 °C (977 °F) to 625 °C (1,157 °F), but usually occurs at 565 °C (1,049 °F). [29] After the Tenifer process, a black Parkerized finish is applied and the slide is protected even if the finish were to wear off. A salt bath uses a liquid salt solution that is usually heated between 750 degrees Fahrenheit and 1050 degrees Fahrenheit. In salt bath nitriding the nitrogen donating medium is a nitrogen-containing salt such as cyanide salt. [17], Gaseous ferritic nitrocarburizing is also known as controlled nitrocarburizing, soft nitriding, and vacuum nitrocarburizing or by the tradenames UltraOx,[18] Nitrotec, Nitemper, Deganit, Triniding, Corr-I-Dur, Nitroc, NITREG-C and Nitrowear, Nitroneg. An added benefit of the process is minimal distortion due to short process cycle within the ferrite phase. Typically, this process involves either a salt bath nitriding or nitrocarburizing to properly treat a barrel. The trade name and patented processes may vary slightly from the general description, but they are all a form of ferritic nitrocarburizing. Due to the relatively low temperature range (420 °C (788 °F) to 580 °C (1,076 °F)) generally applied during plasma-assisted ferritic nitrocarburizing and gentle cooling in the furnace, the distortion of workpieces can be minimized. ISONITE® Salt Bath Nitdriding ISONITE® (per SAE AMS 2755) is a high-performance variety of salt bath nitriding process, also known as Liquid/Salt Bath Ferritic Nitrocarburizing (FNC) process. The process is carried out at 750-1050°F, making it faster than gas nitriding. In combination with oxidation bath it improves corrosion resistance and reduces surface roughness. 3). The gas used for plasma nitriding is usually pure nitrogen, since no spontaneous decomposition is needed (as is the case of gaseous ferritic nitrocarburizing with ammonia). An additional step can be added to the nitrocarburizing process called postoxidation. [16], Other trademarked processes are Sursulf and Tenoplus. The process works to achieve the same result as the salt bath and gaseous process, except the reactivity of the media is not due to the temperature but to the gas ionized state. What is the basic principle of Liquid Nitriding? When properly performed, postoxidation creates a layer of black oxide (Fe3O4), that greatly increases the corrosion resistance of the treated substrate while leaving an aesthetically attractive black color. [28] The final matte, non-glare finish meets or exceeds stainless steel specifications, is 85% more corrosion resistant than a hard chrome finish, and is 99.9% salt-water corrosion resistant. SBN/QPQ SM (salt bath nitriding), or Quench-Polish-Quench, is particularly important to oil field equipment and other manufacturers whose parts are subject to high levels of wear, friction, or erosion. This is because of the low processing temperature, which reduces thermal shocks and avoids phase transitions in steel. [14][15], The process uses a salt bath of alkali cyanate. Tenoplus is a two-stage high-temperature process. To ensure part quality, our salt baths are continuously monitored, with chemistry adjustments made when necessary. [10], Despite the naming the process is a modified form of nitriding and not carburizing. [9] Their process is the widely known as the Tufftride or Tenifer process. [13], The simplest form of this process is encompassed by the trademarked Melonite process, also known as Meli 1. Software Requirements: To view, complete, and print fillable PDF forms you'll need the freely available Adobe Reader software installed on your computer. Due to the main process characteristics like The primary objective of ferritic nitrocarburising treatment is to improve the anti-scuffing characteristics of components. The surface hardness ranges from 800 to 1500 HV depending on the steel grade. This is a crucial reason for the positive, specific surface zone properties of salt bath … It begins with the treating cycle of the nitrocarburizing segment, i.e. This is done to minimize distortion and to destroy any lingering cyanates or cyanides left on the workpiece. It is also known as Liquid/Salt Bath Ferritic Nitrocarburizing (FNC) process. The trade name and patented processes may vary slightly from the general description, but they are all a form of ferritic nitrocarburizing. Stainless steel workpieces can be processed at moderate temperatures (like 420 °C (788 °F)) without the formation of chromium nitride precipitates and hence maintaining their corrosion resistance properties.[25]. It is used to improve wear resistance and fatique strength of cast iron, sintered iron and steel. This porosity is used to contain lubrication. Heckler & Koch use a nitrocarburizing process they refer to as Hostile Environment. This process is preferred for improving tribological and surface properties of ferrous components in addition to improving fatigue strength. a high carbon steel will form a hard, but shallow case. The processes are broken up into four main classes: gaseous, salt bath, ion or plasma, or fluidized-bed. Salt bath nitriding can be an economical method of nitriding providing that both the salt bath chemistry and the salt bath cleanliness are maintained. The first company to successfully commercialize the process was the Imperial Chemical Industries in Great Britain. The finish on a Glock pistol is the third and final hardening process. [30] Besides Glock several other pistol manufacturers, including Smith & Wesson and Springfield Armory, Inc., also use ferritic nitrocarburizing for finishing parts like barrels and slides but they call it Melonite finish. [3][19] The process works to achieve the same result as the salt bath process, except gaseous mixtures are used to diffuse the nitrogen and carbon into the workpiece. [14], A similar process is the trademarked Nu-Tride process, also known incorrectly as the Kolene process (which is actually the company's name), which includes a preheat and an intermediate quench cycle. [4], The first ferritic nitrocarburizing methods were done at low temperatures, around 550 °C (1,022 °F), in a liquid salt bath. In 2010 Glock switched to a gaseous ferritic nitrocarburizing process. Salt Bath Nitriding/Nitrocarburizing was originally created as an alternative to gas nitriding that would produce a more uniform case through surface contact between the substrate and liquid salt. ISONITE® QPQ (per SAE AMS 2753) is a high-performance variety of salt bath nitrocarburizing process. 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. PVD High Energy Deposition Coating Technology, Chrome / Chromium Carbide Coating (CrC-TDH), Plasma Electrolytic Oxidation (PEO) | CeraTough™, Corrosion resistance exceeds chrome plating, Oil & gas components such as impellers, diffusers, and pipe and drill pieces (i.e. The Nitrocarburizing process step is conducted in the MEL 1 / TF 1 bath at 896-1166°F, the standard temperature is usually 1076°F. Ferritic Nitrocarburizing is the thermochemical process that simultaneously diffuses nitrogen and carbon into the surface of ferrous metals. The salts used also donate carbon to the workpiece surface making salt bath a nitrocarburizing process. 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 processes are broken up into four main classes: gaseous, salt bath, ion or plasma, or fluidized-bed. Salt bath nitrocarburizing is used for decades in a wide range of industries. [11], Salt bath ferritic nitrocarburizing is also known as liquid ferritic nitrocarburizing or liquid nitrocarburizing[12] and is also known by the trademarked names Tufftride[3] and Tenifer. In combination with oxidation bath it improves corrosion resistance and reduces surface roughness. Despite the naming the process is a modified form of nitriding and not carburizing. Numerous improvements and design enhancements have occurred over the years. Liquid Salt Bath Ferritic Nitrocarburizing Non-Cyanide Bath(STABILIZED Jul 2019) AMS2753D This specification covers the requirements for an epsilon-iron nitride case on ferrous parts produced by immersion in a low-temperature, agitated, fused salt bath. This is contained in a steel pot that has an aeration system. It is used to improve wear resistance and fatique strength of cast iron, sintered iron and steel. [20], Plasma-assisted ferritic nitrocarburizing is also known as ion nitriding, plasma ion nitriding or glow-discharge nitriding. Grandpower, a Slovakian firearms producer, also uses a quench polish quench (QPQ) treatment to harden metal parts on its K100 pistols. The TENIFER process (TF1) is a salt bath nitrocarburizing of components in molten salt at temperatures around 580° C. Besides the addition of nitrogen, carbon also always diffuses into the surface in every TF1 treatment. [3], The process is used to improve three main surface integrity aspects including scuffing resistance, fatigue properties, and corrosion resistance. [26] Since the introduction of the Glock pistol in 1982, this type of nitrocarburizing with postoxidation finish has become popular as a factory finish for military style handguns. The compound layer exhibits significant improvement in adhesive wear resistance. The surface formed from the reaction has a compound layer and a diffusion layer. Case hardening refers to the “case” that develops around a part that is subjected to a hardening treatment. Nitrocarburizing / Salt Bath Nitriding Ionic liquids offer a significant improvement in wear protection, sliding properties and fatigue strength on all kind of ferrous materials. salt bath equipment NITRIDING SYSTEMS Since the introduction of salt bath nitriding (or ferritic nitrocarburizing) to North America in the 1950s, Kolene has been providing the … Del-Quench™ Standard is a proprietary salt consisting of alkaline nitrate and hydroxide compounds. While the process was very successful with high-speed spindles and cutting tools, there were issues with cleaning the solution off because it was not very water soluble. The temperature used is typical of all nitrocarburizing processes: 550 to 570 °C. The shared attributes of this class of this process is the introduction of nitrogen and carbon in the ferritic state of the material. It is a thermochemical diffusion process whereby nitrogen-bearing salts generate a controlled release of nitrogen at the interface of a ferrous part. Liquid Nitriding (Salt Bath Nitriding) FAQ What is Liquid Nitriding? Salt Bath Nitriding/Nitrocarburizing was originally created as an alternative to gas nitriding that would produce a more uniform case through surface contact between the substrate and liquid salt. Other methods of ferric nitrocarburizing include gaseous process such as Nitrotec and ion (plasma) ones. [7], Because of the cleaning issues the Joseph Lucas Limited company began experimenting with gaseous forms of ferritic nitrocarburizing in the late 1950s. It is 0.05 mm (0.0020 in) thick and produces a 64 Rockwell C hardness rating via a 500 °C (932 °F) nitride bath. salt bath nitriding equipment Since the introduction of salt bath nitriding (or ferritic nitrocarburizing) to North America in the 1950s, Kolene has been providing the necessary process equipment. Parts are typically core treated and finished machined prior to nitriding, with some allowance being made for a slight amount of growth. The next step is a mechanical polish of the nitride layer, thus restoring the original surface finish.