Industrial Heating

46 MAY 2015 ■ IndustrialHeating.com

INDUCTION

HEAT TREATING

ways of accomplishing that result.
The details are too many to cover in this article but will be
addressed in a subsequent work. Generally, the mechanical
details can be heavy duty or lighter duty, provide ease of
adjustment of inductors or lack of adjustment (both may be
suitable for your needs). The method of scanning can vary as
follows:

• Parts move past the inductor on a stationary “tower”
  (Figs. 1-4)


• Part, tooling and “tower” move past the coil through
  stationary bearings (Figs. 5 and 6)


• Coil moves past the parts to be hardened (Figs. 7 and 8)

Each can have pros and cons depending on your application.
Quench recirculation and cooling systems can use different
methods of recirculation, single- or dual-quench valves and
manifolds, different volume of quench holding tanks, different
heaters (or no heaters at all) and various methods of quench
filtration. The power supply and matching capabilities can vary
even though they may be stated as the same rating. Range and
need for adjustment can vary along with the ease of accessing any
needed adjustments.
Controlling and protecting the power supply and the operators
should be reviewed, and cost and accessibility of components is

important. The type of water-cooling and recirculating system

offered for the power components can include different types of

heat exchangers and methods of controlling the temperature as

well as different duty-cycle ratings.

Custom and Automated Systems Can

Vary Widely

If you are considering a custom or automated design, there

are many additional details to resolve. For many years, I was

involved in conceptualizing and quoting custom-designed

machines. Many of these quotes were very general in nature,

and details of many parts are not defined. If you are buying

this type of machine, you should have the experience to ask

about the things that are not defined. It is better for both

parties to understand as much as possible about what is to be

supplied before you place an order. This will avoid later “add-

ons” and misunderstandings after an order is under way. These

tend to be expensive and cause delays in design and build of

the equipment.

Conclusion

There is expertise available to help buyers of induction heating

equipment, and this is especially valuable if the equipment is to

be used for heat treating. Independent consultants with many

Fig. 6. Standard scanner with

moving parts and tooling

through fixed bearings

(courtesy Tucker Induction)

Fig. 10. Custom induction hardening machine for

camshafts (courtesy Inductoheat, Inc.)

Fig. 11. Robot-automated dual-spindle

moving-coil scanner (courtesy Interpower

Induction USA)

Fig. 8. Standard scanner with moving

coil and transformer over fixed parts

and tooling (courtesy EFD Induction)

Fig. 9. Fully automatic ball-stud induction
hardening (courtesy GH Electrotermia S.A.)

Fig. 7. Standard scanner with moving

coil and transformer over fixed parts

and tooling (courtesy GH Induction

Atmospheres)

Fig. 5. Standard scanner with
moving parts and tooling through
fixed bearings (courtesy Inductoheat,
Inc.)