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Induction Hardening Applications [.pdf format]

Tips for successful induction hardening of steels

Authors: Valery Rudnev, GB, EH
Publication: Industrial Heating
Date: 1/1/2005

Steel selection for parts to be induction heating lays a critical role in determining if the required properties can be achieved in the hardening process.

A common misassumption in induction hardening

Authors: Valery Rudnev
Publication: Heat Treating Progress, Professor Induction Series
Date: 9/1/2004

Whenever someone is talking about induction heating, reference is often made to the phenomenon of skin effect. In most publications devoted to induction heating distributions of current density and power density (heat source distributions) along the workpiece thickness/radius are simplified, and described as exponentially decreasing from the surface into the workpiece. However, in some applications, surface hardening in particular, the power density distribution along the radius/thickness has a unique "wave" shape, which differs significantly from the commonly assumed, classical exponential distribution. Here, the power density is maximum at the surface, and decreases toward the core. But then, at a certain distance from the surface, the power density increases, reaching a maximum value before again decreasing. Article discusses frequency selection for induction surface hardening as well as electromagnetic "wave" phenomenon.

Spin hardening of gears revisited

Authors: Valery Rudnev
Publication: Heat Treating Progress, Professor Induction Series
Date: 3/1/2004

In recent years, gear manufacturers have gained additional knowledge about how technology can be used to produce quality parts. The application of this knowledge has resulted in gears that are quieter, lighter, and lower cost, and have an increased load-carrying capacity to handle higher speeds and torques while generating a minimum amount of heat. Not all gears are well suited for induction hardening. For example, bevel, hypoid, and noncircular gears are rarely heat treated by induction. On the other hand, external spur and helical gears, worm gears, and internal gears, racks, and sprockets are among those that typically are induction hardened. Frequency selection and computer modeling of induction hardening of gears is discussed here.

Induction Hardening of Gears: A Review, Part 2

Authors: Valery Rudnev
Publication: Heat Treatment of Metals, England
Date: 1/1/2004

This is an edited version of a section from "Handbook of Induction Heating", 2003

Intricacies of Induction Hardening of Powder Metallurgy Parts

Authors: Valery Rudnev
Publication: Heat Treating Progress, Professor Induction Series
Date: 12/1/2003

An important emerging application of induction heating is for surface hardening of ferrous powder metallurgy (P/M) parts, such as gears, splined hubs, and cams. Induction hardening of P/M parts has several peculiarities compared with hardening wrought steels and cast irons. First, when using induction, remember that the results of induction hardening are more sensitive than those of alternative processes to chemical composition, the microstructure of the part before hardening, and the part's physical properties. Article discusses specifics of induction hardening powder metallurgy components.