Technical Information

Features of Induction Quenching

Features of Induction Hardening

Using induction heating (IH) process that makes use of the electromagnetic induction phenomenon, the surface of a steel part is rapidly heated to a high temperature in seconds and then rapidly cooled, and in this way it is possible to harden the surface of the steel parts. Induction hardening has been widely applied to improve the wear resistance and the fatigue endurance of steel parts in such products as automobiles, construction equipment, machine tools and so on. In addition, it has attracted attention as W-Eco (Ecological and Economical) heat treatment method. This is because it features low-level CO2 emissions, a clean environment and environmentally-friendly technology, and it offers the advantage of energy conservation through outstanding productivity by rapid heating using IH technology. Features of Induction  Heat Treatment

Features of Usage

Advantage Main Points
①Outstanding thermal efficiency Self-heating, rapid and surface heating up to 1000℃ in a few second
② High flexibility of heating cycle Combination of frequency, output power, heating coil and cooling system
→ Wide range of heating and cooling condition settings
③ Clean environment Direct heating using electricity
④ Speedy start and shutdown of operation Direct heating using electricity
⑤ Ease of automation Introduction of computerized control and in-line process
⑥ Space-saving Development of high efficiency transistor power supply

Features of Material quality

Advantage Main mechanical characteristics
Fatigue Friction Toughness Cost
① High surface hardness × -
② Deep and adjustable hardened layer depth
(Against carburizing and nitriding)
Surface fracture○
Internal fracture◎
Rolling○ - -
③ High level surface compressive residual stress Rolling◎
Surface △
④ Microstructure(1) Gain size
(2) Temper carbides
⑤ Low decarburization
⑥ Low distortion
W(double)-Tei (Stabilized and low) distortion
⑦ Low material costs


Double (W) low (stabilized) distortion

Variation in the amount of heat-treatment distortion in each steel part is reduced by controlling the material and heat-treatment conditions (stabilized distortion), and low heat-treatment distortion is achieved by changing the shape of the steel parts to incorporate the heat-treatment distortion.

Double (W) low (tabilized ) distortion

Double (W)-Eco

Compared to the other methods of surface heat treatment, induction heat treatment is an environmentally-friendly method (Ecological) and has high economic efficiency (Economical).

Comparison of carbon dioxide emissions (calculated values)

Comparison of energy conservation (calculated values)

Comparison of energy conservation (calculated values)

※Comparison in heat-treated spur gear with126mm in tooth tip diameter, 20mm in tooth with and in module 3 with 40 teeth.