About Commercial Nitrocarburising For Wear Resistance
Ferritic nitrocarburizing or FNC, also known by theproprietary names ALFANIT,(Liquid Nitriding) is a range ofproprietary case hardening processes that diffuse nitrogen and carbon into ferrous metalsat sub-critical temperatures during a salt bath. Other methods of ferriticnitrocarburizing include gaseous processes such as Nitrotec and ion (plasma)ones. The processing temperature rangesfrom 525 C to 625 C, but usually occursat 565 C. Steel and other ferrous alloys remain in the ferritic phaseregion at this temperature. This allows for better control of the dimensionalstability that would not be present in case hardening processes that occur whenthe alloy is transitioned into the austenitic phase.
Nitrocarburising: KNITCOR (QuenchPolish Quench) coating begins with nitrocarburising the surface, which ofteninvolves using gaseous substances or salt solution to diffuse carbon andnitrogen on the metal surface. This process often forms a rigid material withanti-corrosion properties on the metal surface. The two methods used in nitrocarburisingare gas and salt bath nitrocarburizing.
Gas nitrocarburising: Themetal component or substrate requires a mixture of carbon and nitrogen gasunder extreme temperatures to achieve nitrocarburizing for the metal surface.
Salt bathnitrocarburising: Salt bath, on the other hand, requires asalt solution containing carbon and nitrogen compounds with the metallicsubstrate immersed in it to achieve nitrocarburizing.
Polishing: The next stepafter achieving nitrocarburising is polishing, ensuring no roughness on thesurface, and giving it a fine, sleek, and pleasant surface finish. Youll haveto use either mechanical or chemical-assisted polishing to achieve a smoothfinish. Fine abrasive materials are used in removing any imperfections on thesurface of the coated material when using mechanical methods to achieve thepolishing process. It often leaves a crease-free surface that is pleasant tothe sight.
Quenching: The last step in theQuench Polish Quench coating process is quenching the excessive heat generatedduring the coating process. Cooling is often done rapidly to achieve a firmcoating surface. Two major methods are often used to quench this extreme heat:water and polymer quenching.
Waterquenching involvessimply submerging the coated material into water or brine to achieve rapidcooling and a rigid coated surface.
Polymer quenching: In this case,cooling involves using a polymer solution in which you submerge the coatedmaterial. This method is often better than water quenching, considering it isbetter controlled.
Superior Surface Hardness and PerformanceNitrocarburising introduces a tough, hard surface to steel components, dramatically elevating their wear resistance and fatigue strength. The enhanced case, while thin, achieves remarkable hardness-up to 1200 HV-without sacrificing the core's mechanical properties, making parts exceptionally durable in demanding industrial applications.
Efficient Process for Industrial ApplicationOperating between 540C and 580C, the nitrocarburising process uses controlled atmospheres, including gaseous or salt bath methods. Treatment time is customizable from 1 to 4 hours based on required depth, providing flexibility for manufacturers and service providers to meet industry-specific needs efficiently.
Ideal for Automotive, Tooling, and ManufacturingThis treatment is key for industries requiring elevated wear and corrosion resistance, such as automotive drivetrain components, precision tooling, and critical manufacturing assemblies. The process yields components that perform reliably even under high stress and corrosive environments, supporting production in India and beyond.
FAQ's of Nitrocarburising For Wear Resistance:
Q: How does nitrocarburising enhance the wear resistance of steel components?
A: Nitrocarburising introduces nitrogen and carbon into the steel's surface at elevated temperatures, creating a hardened case of 0.2 to 0.7 mm depth. This layer achieves hardness up to 1200 HV, significantly improving resistance against wear and surface fatigue while preserving the ductile core.
Q: What is the typical process temperature and treatment time for nitrocarburising?
A: The process is carried out at temperatures between 540C and 580C, with a treatment duration ranging from 1 to 4 hours. The exact cycle depends on the desired case depth and application requirements.
Q: Where is nitrocarburising commonly applied in industry?
A: Nitrocarburising is widely employed in the automotive sector, tooling, and manufacturing industries. It is ideal for enhancing parts such as gears, crankshafts, dies, and components exposed to friction or corrosive environments.
Q: When should manufacturers consider nitrocarburising for their components?
A: Manufacturers should opt for nitrocarburising when improved surface hardness, fatigue strength, and corrosion resistance are needed, but it is important to retain the core's ductility and toughness. This is especially relevant for high-stress, high-performance applications.
Q: What are the main benefits of choosing nitrocarburising for steel parts?
A: Key benefits include superior surface hardness, improved fatigue strength, enhanced corrosion resistance, and protection without compromising core properties. These results extend component life and lower maintenance costs in service.
Q: How does the controlled atmosphere affect the nitrocarburising process?
A: The controlled gaseous or salt bath atmosphere ensures precise diffusion of nitrogen and carbon, resulting in a uniform hard surface layer. It also prevents unwanted oxidation and guarantees consistent quality.