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Hub AI
Ferritic nitrocarburizing AI simulator
(@Ferritic nitrocarburizing_simulator)
Hub AI
Ferritic nitrocarburizing AI simulator
(@Ferritic nitrocarburizing_simulator)
Ferritic nitrocarburizing
Ferritic nitrocarburizing or FNC, also known by the proprietary names "Tenifer", "Tufftride", Melonite, and "Arcor", is a range of proprietary case hardening processes that diffuse nitrogen and carbon into ferrous metals at sub-critical temperatures during a salt bath. Other methods of ferritic nitrocarburizing include gaseous processes such as Nitrotec and ion (plasma) ones. The processing temperature ranges from 525 °C (977 °F) to 625 °C (1,157 °F), but usually occurs at 565 °C (1,049 °F). Steel and other ferrous alloys remain in the ferritic phase region at this temperature. 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. There are four main classes of ferritic nitrocarburizing: gaseous, salt bath, ion or plasma, and fluidized-bed.
The process improves three main surface integrity aspects: scuffing resistance, fatigue properties, and corrosion resistance. It has the advantage of inducing little shape distortion during the hardening process. This is because of the low processing temperature, which reduces thermal shocks and avoids phase transitions in steel.
The first ferritic nitrocarburizing methods were done at low temperatures, around 550 °C (1,022 °F), in a liquid salt bath. The first company to successfully commercialize the process was the Imperial Chemical Industries in Great Britain. ICI called their process "the cassel" due to the plant where it was developed or "Sulfinuz" treatment because it had sulfur in the salt bath. 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.
Because of the cleaning issues, Lucas Industries began experimenting with gaseous forms of ferritic nitrocarburizing in the late 1950s. The company applied for a patent in 1961. It produced a similar surface finish as the Sulfinuz process, except for the formation of sulfides. The atmosphere consists of ammonia, hydrocarbon gases, and a small amount of other carbon-containing gases.
This innovation spurred the development of a more environmentally friendly salt bath process by the German company Degussa after acquiring ICI patents. Their process is widely known as the Tufftride or Tenifer process. Following this, the ion nitriding process was invented in the early 1980s. This process had faster cycle times, required less cleaning and preparation, formed deeper cases, and allowed for better control of the process.
Despite the naming, the process is a modified form of nitriding and not carburizing. The shared attribute of this class of this process is the introduction of nitrogen and carbon in the ferritic state of the material. The processes are divided into four main classes: gaseous, salt bath, ion or plasma, or fluidized-bed. The trade name and patented processes may vary slightly from the general description, but they are all a form of ferritic nitrocarburizing.
Salt bath ferritic nitrocarburizing is also known as liquid ferritic nitrocarburizing or liquid nitrocarburizing and is also known by the trademarked names "Tufftride" and "Tenifer".
The simplest form of this process is encompassed by the trademarked "Melonite" process, also known as "Meli 1". It is most commonly used on steels, sintered irons, and cast irons to lower friction and improve wear and corrosion resistance.
Ferritic nitrocarburizing
Ferritic nitrocarburizing or FNC, also known by the proprietary names "Tenifer", "Tufftride", Melonite, and "Arcor", is a range of proprietary case hardening processes that diffuse nitrogen and carbon into ferrous metals at sub-critical temperatures during a salt bath. Other methods of ferritic nitrocarburizing include gaseous processes such as Nitrotec and ion (plasma) ones. The processing temperature ranges from 525 °C (977 °F) to 625 °C (1,157 °F), but usually occurs at 565 °C (1,049 °F). Steel and other ferrous alloys remain in the ferritic phase region at this temperature. 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. There are four main classes of ferritic nitrocarburizing: gaseous, salt bath, ion or plasma, and fluidized-bed.
The process improves three main surface integrity aspects: scuffing resistance, fatigue properties, and corrosion resistance. It has the advantage of inducing little shape distortion during the hardening process. This is because of the low processing temperature, which reduces thermal shocks and avoids phase transitions in steel.
The first ferritic nitrocarburizing methods were done at low temperatures, around 550 °C (1,022 °F), in a liquid salt bath. The first company to successfully commercialize the process was the Imperial Chemical Industries in Great Britain. ICI called their process "the cassel" due to the plant where it was developed or "Sulfinuz" treatment because it had sulfur in the salt bath. 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.
Because of the cleaning issues, Lucas Industries began experimenting with gaseous forms of ferritic nitrocarburizing in the late 1950s. The company applied for a patent in 1961. It produced a similar surface finish as the Sulfinuz process, except for the formation of sulfides. The atmosphere consists of ammonia, hydrocarbon gases, and a small amount of other carbon-containing gases.
This innovation spurred the development of a more environmentally friendly salt bath process by the German company Degussa after acquiring ICI patents. Their process is widely known as the Tufftride or Tenifer process. Following this, the ion nitriding process was invented in the early 1980s. This process had faster cycle times, required less cleaning and preparation, formed deeper cases, and allowed for better control of the process.
Despite the naming, the process is a modified form of nitriding and not carburizing. The shared attribute of this class of this process is the introduction of nitrogen and carbon in the ferritic state of the material. The processes are divided into four main classes: gaseous, salt bath, ion or plasma, or fluidized-bed. The trade name and patented processes may vary slightly from the general description, but they are all a form of ferritic nitrocarburizing.
Salt bath ferritic nitrocarburizing is also known as liquid ferritic nitrocarburizing or liquid nitrocarburizing and is also known by the trademarked names "Tufftride" and "Tenifer".
The simplest form of this process is encompassed by the trademarked "Melonite" process, also known as "Meli 1". It is most commonly used on steels, sintered irons, and cast irons to lower friction and improve wear and corrosion resistance.