Besides, the process has few advantages, quick heating of the workpiece being the only one worth mentioning. The atmosphere consisted of ammonia, hydrocarbon gases, and a small amount of other carbon-containing gases. The salt-bath nitrocarburizing treatment was performed at 480 °C for 5 h, the operating atmosphere being the one typically used in the Sursulf nitrocarburizing process : CNO¯ (36 ± 2%), CO 3 2– (19 ± 2%), CN¯ (≤ 0.8%). It produced a similar surface finish as the Sulfinuz process with the exception of the formation of sulfides. With the introduction of nitrogen in the diffused zone fatigue properties are enhanced. The actual gas mixtures are proprietary, but they usually contain ammonia and an endothermic gas. It is a thermochemical diffusion process whereby nitrogen-bearing salts generate a controlled release of nitrogen at the interface of a ferrous part. Ferritic Nitrocarburizing is the thermochemical process that simultaneously diffuses nitrogen and carbon into the surface of ferrous metals. [27], Glock Ges.m.b.H., an Austrian firearms manufacturer, utilized the Tenifer process until 2010, to protect the barrels and slides of the pistols they manufacture. The surface hardness ranges from 800 to 1500 HV depending on the steel grade. Version 9 or later of Adobe Reader is required. The primary objective of ferritic nitrocarburising treatment is to improve the anti-scuffing characteristics of components. 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. It is used as a post-nitride ‘quench bath.’ This neutralizes any potential toxic compounds which may have formed as a result of nitriding bath reactions reacting with any nitriding salt residues adhering to the components or fixtures. The salts used also donate carbon to the workpiece surface making salt bath a nitrocarburizing process. Salt bath nitrocarburizing is used for decades in a wide range of industries. It has the added advantage of inducing little shape distortion during the hardening process. Liquid Nitriding (Salt Bath Nitriding) FAQ What is Liquid Nitriding? The surface formed from the reaction has a compound layer and a diffusion layer. [21][22][23][24] In this technique intense electric fields are used to generate ionized molecules of the gas around the surface to diffuse the nitrogen and carbon into the workpiece. Tenoplus is a two-stage high-temperature process. Following this the ion nitriding process was invented in the early 1980s. 2). The diffusion layer contains nitrides and carbides. The temperature used is typical of all nitrocarburizing processes: 550 to 570 °C. The company applied for a patent by 1961. The processing temperature ranges from 525 °C (977 °F) to 625 °C (1,157 °F), but usually occurs at 565 °C (1,049 °F). 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. Salt Bath Nitriding is a ferritic nitrocarburizing process which involves the diffusional addition of both nitrogen and carbon to the ferrous surface at temperatures within the ferritic phase. The processes are broken up into four main classes: gaseous, salt bath, ion or plasma, or fluidized-bed. Houston Unlimited, Inc. offers a salt bath nitriding process, also referred to as liquid salt bath ferritic nitrocarburizing. Despite the name, the process is really a modified form of nitriding with carbon added. The intermediate quench is an oxidizing salt bath at 400 °C (752 °F). Salt bath nitrocarburizing is used for decades in a wide range of industries. pre-heat, Del-Nite salt, Delamin Del-quench salt bath quench (SBQ), which produces a layer of epsilon iron nitride, Fig. 3). A salt bath uses a liquid salt solution that is usually heated between 750 degrees Fahrenheit and 1050 degrees Fahrenheit. This also inversely affects the depth of the case; i.e. [4], The first ferritic nitrocarburizing methods were done at low temperatures, around 550 °C (1,022 °F), in a liquid salt bath. 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). 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. This allows for better control of the dimensional stability that would not be present in case hardening processes that occur when the alloy is transitioned into the austenitic phase. [7], Because of the cleaning issues the Joseph Lucas Limited company began experimenting with gaseous forms of ferritic nitrocarburizing in the late 1950s. [29] After the Tenifer process, a black Parkerized finish is applied and the slide is protected even if the finish were to wear off. These processes are most commonly used on low-carbon, low-alloy steels, however they are also used on medium and high-carbon steels. Short process cycle within the ferrite phase pot that has an aeration system use a nitrocarburizing process postoxidation. Also carbon ) is molten salt this is done to minimize distortion and to destroy any lingering cyanates or left. Imperial Chemical industries in salt bath nitrocarburizing Britain other iron alloy metals in a wide range of industries left on workpiece! 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