Heat treatment refers to the process where softer steel is hardened so that it stands up to use as a knife blade. Wanting to curve a file to clean the inside of a spoon. It is the purpose of this article to examine the causes of. Heat treatment processes can be tailored to maximize the life and optimize the performance of a gear in its service application by tailoring the heat treatment to produce specific desired properties. However, parallel axes spur and helical gears are the main gears in automotive transmission. One is a process of heat treatment and other is a extrinsic property of a material. Previous processing variables, as well as the heat treatment parameters of time, temperature, agitation, and quenchant must be carefully scrutinized for proper control of microstructure, distortion, and control of microstructure. Typical gear tooth hardness after through hardening ranges from 32 to 48 hrc.
The effects of heat treatment on the microstructure and. The heat treating of gears presents a difficult challenge to both the heat treater and the gear. Heat treating represents a significant por tion or about 30% of a typical gear. Lindell metal improvement company, inc twin disc, inc. Volume 4d is a practical guide to heat treating irons and steels, and is particularly helpful in the context of selecting materials and determining part geometries and process plans. Automotive gears represent another important category of components that are heavily stressed and require high levels of performance in the areas of both fatigue and wear resistance. Heat treatment process optimization for face gears based.
Jade band marigold introduction atlas 4340 is a nominally 1. Heat treat distortion of gears is discussed in detail for the major heat treat process, and a case history of each successful gear heat treat process is included. A variety of heat treatment techniques exist for case hardening gears. Cogmatic uses a spin induction heat treatment process to provide a case hardness for customer parts. Unfortunately, very little has been published on heat treatment of gears that is both easy to understand and useful to the gear engineer. Heat treating a knife blade heat treat and tempering. Flowoptimization to enhance gas quenching efficiency for. To heat treat steel, i heat it up beyond cherry red to glowing red. Using the thermal boundary conditions predicted by cfd models, heat treatment simulations have been developed to predict the component response during.
Manufacturers guide to heat treating large gears ipsen usa. The process heat treatment is carried out first by heating the metal and then cooling it in water, oil and brine water. The heat treatment processes covered are annealing, carburizing, hardening, lowpressure carburizing, induction hardening, through hardening, and nitriding. Since gears are applied for various usages, such as industrial machinery, electric electronic devices, household goods and toys, and composed of many kinds of materials, we like to. In terms of numerical simulation of heat treatment for gears, liu et al. Although casehardened gears tend to give a higher torque capacity than nitrided. Sort by date 1 heat treating challenges for the future marchapril 1996. How to avoid heat treatment problems when launching new gear. Pdf heat treating and quenching are arguably the most critical operations in the manufacture of gears. Aside from prelaunch problem resolution as discussed above, ppap can also be used to establish and document fixed heat treatment processes and force the.
The purpose of heat treatment is to soften the metal, to change the grain size, to modify. Gear materials such as sae 1045, 4340, and cast irons gray, malleable, ductile are good candidates for this technology. Selection of heat treat process for optimum gear design. Heat treatment processes in gear design prepared by. A variety of heat treatment process choices exist for hardening a gear, each designed to increase gear hardness. Gear hardening and tempering heat treating with the.
Heat treatment is the second album by rock and roll singersongwriter graham parker and the rumour. Heat treating heavyduty gears gear solutions magazine. Gear racks are utilized to convert rotating movement into linear motion. The heat treatment of any metal alloy contributes greatly to the properties the part exhibits. The handle end of half round files rarely gets much wear and makes great spoon files. Effect of quenchant flow on the distortion of carburized. Selecting the best carburizing method for the heat.
Efficient layout process of cylindrical gears with. The focus of this article will be on heat treatment of gears intended for heavy duty service applications. Heat treatment heat treatment is an operation or combination of operations involving heating at a specific rate, soaking at a temperature for a period of time and cooling at some specified rate. Surface combustion, stack metallurgical services and ipsen offer servicesadvice on the unique challenges of heat treating large gears. The influence of materials and geometry types of gears gears play an essential role in the performance of the products that we rely on in our everyday lives.
Gear materials and heat treatments it is essential to select proper materials and heat treatments in accordance with the intended application of the gear. Heat treatment processes in gear design free download as powerpoint presentation. Isaiah paul janzen a thesis submitted to the faculty of. Selecting the best carburizing method for the heat treatment of gears daniel h. Most steels that are used for throughhardened gears have medium carbon.
Heat treatment processes in gear design heat treating. Surface hardening, treatment of steel by heat or mechanical means to increase the hardness of the outer surface while the core remains relatively soft. What factor of safety do they appear to use in this catalog. A practical guide for engineers basm014 increased demand for gears to transmit more power through smaller, lighter, quieter, and more reliable packages that must operate.
Heat treating and quenching are arguably the most critical operations in the manufacture of gears. I heat locally to a low red with a cutting torch while the extra file. Failure analysis of heat treated steel components l. Introduction in the automotive industry, in order to achieve a sufficient hardness distribution. To understand why heat treating is important we look to the model of material science figure 1. Induction hardening is commonly used in the heat treatment of gears. The influence of materials and geometry types of gears gears play an essential role in the performance of the prod. Heat treatment of gears a practical guide for engineers. Manufacturing of gears presents a demanding challenge for metallurgists in. Heat treatment of steel gears heat treating of irons and.
Spur gears from the catalog page shown in figure 123 are made from a. The combination of a hard surface and a soft interior is. It is these processes that provide a gear with the proper mechanical and wear properties to. Heat treatment of pm gears heat treatment of pm gears can be performed with the same type of equipment used for processing regular steel gears.
However, distortion of the gear after heat treatment offers the engineer a challenging opportunity not only in ensuring a high quality product but also in controlling manufacturing costs. Unit 5heat treatment 21 hardening and hardness are two very different things. This heat treating process is localized to the entire tooth profile where case hardness. Due to current capacity constraints, printed versions of our publications including standards, technical papers, edge reports, scholarly journal articles, books, and paint chips may experience shipping. Although only a portion of the complete test program could be presented here, the results are representative of the entire study. Borisov 1 metal science and heat treatment volume 7. Heat treat processes for gears gear solutions magazine. Over the last 50 years, a great deal of research has been carried out and published in the disciplines. Throughhardening low alloy steel bar 4340 colour code. During the years since, however, i came to look at this little. If no drawing is available, knowledge of what the parts are going to. The correct hardness depends on the application of the steel being treated. Steels in particular respond well to heat treatment.
Heat treatment is used to improve the mechanical properties. Heat treatment and quenching of gears is a complex process. Improvements in dimensional control of heat treated gears. Totten asm international materials park, ohio 440730002. Includes heat treatment sections on through hardened, flame hardened, induction hardened, carburized, carbonitrided, and nitrided gears. Heat treatment makes a metal more useful by making it stronger and more resistant to impact, or alternatively, making it more malleable and ductile. A close followup to the debut album, howlin wind, heat treatment was well received by critics and. Heat treatment of gears a practical guide for engineers 06732g free ebook download as pdf file. The unique phases that steels have over a range of. In addition, the torque capacity strongly depends on the chosen gear materials, heat treatment and gear quality. Gear technology marchapril 2004 35 gear heat treatment. The purpose of heat treating is to bring steel to a hardened state. Heat treatment is a critical and complex element in the manufacturing of gears that greatly impacts how each will perform in transmitting power or carrying motion to other components in an assembly.