Surface hardening with induction heating is a process of using the principle of electromagnetic induction to rapidly inductively heat the workpiece and then rapidly cool the workpiece. Induction hardening can effectively improve the surface hardness of the workpiece and increase its wear resistance. The induction heating time is short, the heating speed is fast, the workpiece is rarely oxidized and decarburized, and the workpiece is less deformed. In addition, induction hardening equipment can be easily integrated into the production line to automate the production process.

Induction hardening is often used for the surface hardening of small module gears and shaft parts, the hardening of medium and small module gears, the surface hardening of camshafts and crankshafts, the surface hardening of saw teeth, blades, and thin parts, and the surface hardening of cold rolls.

The main purpose and benefits of induction hardening of mechanical parts

1. Improve the wear resistance of the surface of the parts
Induction hardening was originally applied to the surface of crankshaft journals to improve the wear resistance of the journals. Prior to this, the crankshaft was hardened and tempered, and induction hardening greatly improved the wear resistance of the crankshaft journal.

2. Improve the fatigue strength of parts
Induction hardening can improve the fatigue strength of hardened parts. After induction hardening of automobile half shafts, the fatigue strength was greatly improved. After induction hardening of the steering knuckle ball stud, the bending fatigue life of the part increased from 80,000 times to more than 2 million times. The induction hardening of the crankshaft fillet doubles the fatigue strength of the crankshaft, and the fatigue strength of the crankshaft of some products reaches more than 700MPa.

3. Reduce distortion
Due to the long process time of carburized gears, the distortion after hardening is large. The gears undergo induction hardening, especially synchronous dual-frequency gear hardening; the process time is short, the distortion is small, the gear accuracy is improved, and the noise is reduced.

4. Energy saving, material saving, labor saving, and environmentally protective
Parts such as gears are made of low hardenability steel and are induction hardened. First, steel has no alloying elements, saving material costs. Secondly, induction heating is local heating and hardening, and the time is short, so it saves energy. In addition, induction hardening can realize automatic online production, which saves labor, and there is no emission of harmful gases in the production process, which is more conducive to protecting the environment.

Disadvantages of induction hardening

1) It is troublesome to match the equipment with the hardening process, because the electrical parameters often change.
2) The parts that need to be hardened must have certain induction coils corresponding to them.
3) It requires the use of specialized and strong quenching machine tools, and the cost is high.
4) Equipment maintenance is more complicated. Modular hardening equipment is now generally used, and parts are easy to replace.


Induction hardening can effectively improve the physical properties of steel workpieces. Using induction hardening equipment allows precise control of the hardening process, heating only the areas that need to be hardened. In addition, induction heating machines can easily automate the hardening process and improve production efficiency.