Press

Press  | 04/24/2015  | created by Markus Isgro

Benefits of induction surface layer hardening compared to other hardening processes

Induction surface layer hardening is an electrothermal process used in the industry for various workpieces, such as gear wheels and shafts. As the name suggests, induction surface layer hardening does not harden the entire workpiece, only the surface area. This means, for example, that while the teeth on gear wheels are very hard, the core of the workpiece continues to have a certain amount of elasticity to enable it to deal with impact-type stresses such as those that occur on gearbox components.

Induction surface layer hardening in practice

The hardening process for induction surface layer hardening is much shorter than that used for case hardening. Depending on the required hardness profile, the heating time is between 0.2 and a few seconds – enough time to heat the workpiece to over 900°C. Immediately after the heating process the workpiece undergoes quenching, which is what ultimately gives it its hardness. The fast heating and just as fast cooling allow the induction surface layer hardening process to take place since the generated heat cannot penetrate into the workpiece core. Naturally, it is possible, in theory, to harden the entire workpiece by induction heating, if the heating times are adjusted accordingly.

Precise control required

Induction surface layer hardening is a process which requires the precise control of the applied energy, frequency and inductor. All three components must be precisely tailored to the workpiece and the required hardness profile to allow uniform hardening to take place around the contours of the workpiece. In the EMAG Group this precision is delivered by eldec, based in Dornstetten. Their MIND hardening machines satisfy every requirement for the precision hardening of workpieces with the most diverse designs: be it toothed or worm gears, chucked parts or shafts, the MIND series can be used for almost any project. The modular design of the machines provides maximum flexibility in terms of equipment and the range of applications. The combination of multiple machines is just as possible as the use of multiple generators for different hardening processes on a single system.

The induction hardening machines in the MIND series – induction surface layer hardening on an industrial scale for a wide range of applications.