It is most commonly used for plain carbon steels. The case depths most commonly requested are in the 0. We have numerous furnaces capable of carbonitriding. If you have a large volume of parts, submit a quote request and we will respond promptly. Carbonitriding Capabilities on Furnace Variables All our carbonitriding cycles are run in batch-type furnaces for optimum process and lot-control.
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Case hardening basics: Nitrocarburizing vs. Here, we examine two case hardening techniques —nitrocarburizing and carbonitriding—and explain the differences between the techniques and the benefits that result from their use. Case hardening 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.
Material, part specs and intended uses dictate whether nitrocarburizing or carbonitriding is the best case hardening method. Carbonitriding During carbonitriding, parts are heated in a sealed chamber well into the austenitic range—around degrees Fahrenheit—before nitrogen and carbon are added. Because the part is heated into the austenitic range, a phase change occurs and carbon and nitrogen atoms can diffuse into the part. The nitrogen comes in the form of ammonia, which cracks on the surface of the part to provide nitrogen that diffuses into the steel.
Adding nitrogen also helps a part maintain hardness during use in high-heat settings. 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.
Carbonitriding typically achieves greater case depths compared to nitrocarburizing. The carbonitriding process usually takes a few hours achieve the desired results: a part with high surface hardness but with a relatively ductile core. The process concludes with a quench. Carbonitriding is used to harden surfaces of parts made of relatively cheaper and easily-machined steels, like stamped automotive parts or wood screws.
The process makes parts more resistant to wear and increases fatigue strength. Nitrocarburizing Nitrocarburizing also entails the dissolution of carbon and nitrogen into a workpiece, but, compared to carbonitriding, more nitrogen is used in nitrocarburizing. There are two forms of nitrocarburizing: austenitic and ferritic. Austenitic nitrocarburizing refers to the temperature of the nitrogen-enriched zone at the surface of a part.
A phase change occurs in that zone, allowing the nitrogen to diffuse. Ferritic nitrocarburizing is conducted at a lower temperature where no phase change occurs. Case depths as a result of nitrocarburizing are typically more shallow compared to carbonitriding. Within that temperature range, nitrogen atoms can diffuse into the steel but the risk of distortion is decreased. Due to their shape and size, carbon atoms cannot diffuse into the part in this low-temperature process.
Workpieces improved by nitrocarburizing include drive train components in automobiles and heavy equipment, firearm components like barrels and slides and dies for manufacturing processes. Nitrocarburizing decreases the potential for corrosion in parts and enhances their appearance. The process generally takes only a few hours. The case hardening experts at Paulo have the tools and expertise to ensure your parts are up to spec and up to the job. If you have questions about these or other heat treating processes, be sure to get in touch or read through our heat treating guide below: Heat treating An introduction to heat treating procedures.
Case hardening basics: Nitrocarburizing vs. carbonitriding
Process[ edit ] Carbonitriding is similar to gas carburization with the addition of ammonia to the carburizing atmosphere, which provides a source of nitrogen. Nitrogen is absorbed at the surface and diffuses into the workpiece along with carbon. Carbonitriding tends to be more economical than carburizing, and also reduces distortion during quenching. The lower temperature allows oil quenching, or even gas quenching with a protective atmosphere. Characteristics of carbonitrided parts[ edit ] Carbonitriding forms a hard, wear-resistant case, is typically 0. Case depth is tailored to the application; a thicker case increases the wear life of the part. Carbonitriding alters only the top layers of the workpiece; and does not deposit an additional layer, so the process does not significantly alter the dimensions of the part.