Best Heat Treatment For Gears PDF

/ Best Heat Treatment For Gears? Categories: News Heat treating is a very key production step during the gear manufacturing process. This can represent up to 30% of the manufacturing costs. By modifying the physical, chemicaland metallurgical properties of the gear, hea...

/ Best Heat Treatment For Gears? Categories: News Heat treating is a very key production step during the gear manufacturing process. This can represent up to 30% of the manufacturing costs. By modifying the physical, chemicaland metallurgical properties of the gear, heat treatment can optimize and even extend the life of the gear, making this process a critical one in gear manufacturing. Different methods of heat treatment can improve both surface and core hardness,boost machinability, enhance ductility and strength, minimizedistortions, and reduce wear and tear. Some heat treatment processes target the while others may be whole gear, directed at certain parts of the gear, such as the teeth. Hence,depending on the requirements of the specific gear application, different types of heat treatments may be utilized. Heat Treatment Processes  other hand, this method is suited to process products with gear and axiS integrated or large gears because the gear tooth can be hardened partially. 3. Nitriding Frequently used for gears made of steel which contains chrome or molybdenum. Among the various kinds of steel which are suitable for nitriding, aluminum-containing steel produces particularlya powerful effect and are called "nitridesteel". In gears are heated in nitrogen gas to form a layer of iron nitride nitration, of0.1mm to 1mm thickness on the gear surface. The nitriding can give hardness higher than carburizing and induction hardening, but the layer hardened by nitriding is thinner than other heat treatments. Meanwhile, the temperature necessary for nitriding is relatively low, 500to 600 degrees Celsius. In contrast, products need to be heated up to 800 degrees Celsius in carburizing and induction hardening. Therefore, nitriding causes no quenching cracks or distortion unlike other heat treatments. Generally, the nitriding is carried out in the step of processing gears final as it doesn't cause deformation and gives high hardness. Related links: Materials for Gears and Heat Treatment Gear Materials  $44 3164 4524 S35 3331 Martensite Hardness There are several key heat treatment processes used in gear manufacturing today. Annealing and normalizing are processes used to soften the gear or part and relieve residual stress. Some of the more prevalentprocesses to harden thegear are through or direct hardening, case hardening-carburizing, carbonitriding. nitriding. nitrocarburizing, and applied energy hardening– flame,laser, induction. Annealing refers to the process of heating the gear to a high, pre-determined temperature for an extended period and then slowly cooling it. This results in the recrystalization of the material, thereby improving machinability. Normalizing is an annealing treatment where the material is heated above its upper critical temperature, and then allowed to air-cool. This creates a partthat is very machinable but harder than an annealed part. Through hardening process, usually used on medium and high carbon steels, is the process of heatingand cooling the material while maintainingthe carbon levels in the steelduring the process. Steels such as AISI 1045,4130, 4140,4145, 4340 and 8640 are suitable for through hardening. However, this process will not work on mild steel with low carbon content; here,the case hardening process is more suitable. In the latter process, the carbon content of the surface layer of thegear is increased via prolonged contact with a chemically reactive source of carbon at high temperatures. On cooling, this process creases a hardened surface layer, or a 'case.'Case hardening creates a gear with a softer core for better ductility, but with a harder surface for more pitting resistance. Carburizing is one of the most widely used case hardening techniques. In this thermochemical process,carbon is diffused into the surface of the gear to improve its response to heat treatment and develop a hard, wear-resistantsurface.Steels suitablefor carburizing are AlSI 1018, 4320, 5120,20MnCr5 and ZF-7B. Carbonitriding is a modificationof the carburizing process, where ammonia is added to the carburizing atmosphere in order to add nitrogen to the case. AISI 1018 and 1117 are steels suitable for carbonnitriding. Nitriding is the process of diffusing nitrogen into the surface of steel, producing a very hard,extremely smooth surface finish. Commonly nitrided steelsinclude AISI 4140, 4150,4340 and AMS 6475.