Induction hardening offers excellent hardness distribution with minimal defects

Induction hardening offers significant advantages over traditional methods for heat-treating steel, alloy, and other metal parts. This process is perfect for metal with a carbon content of more than 0.3%, particularly hardened steel with a low alloy content (C34, C35, C60, etc.), as described in the DIN EN 100083 industry norm. Shafts, gears, armatures, sprockets and other components can all be hardened using this induction process.

The process is very demanding on the equipment and the inductor used. Ideal hardening results can only be achieved by perfectly matching a precisely controlled energy source with an optimum inductor design. eldec's experienced engineers custom design the induction coils to meet customer unique specifications, including single turn, two-turn, face-heating, clamshell, and clamp inductors. Every machine is completely inspected and tested to ensure optimum power and heat settings.

Heating directly with induction hardening

Induction hardening in Faridabad is a process in which the heat is generated directly in the work piece. The principal advantage of this type of heat treatment is that the material quickly reaches the desired temperature to produce hardened metal parts. With traditional heat treatments such as flames, ovens, or by convection, heat is applied to the part by heating up the surface layer. These methods take considerably longer and require significantly more energy to produce the desired hardness. Induction hardening, by contrast, offers extremely short heating times. It is a very effective and attractive method in the manufacturing of steel shafts, components, and other metal parts across a range of industries. Additionally, induction heating can be very precisely controlled via the power, frequency, and inductor geometry. This minimizes deformities in the workpiece and ensures the efficiency of the process.

How induction hardening works

The primary application of this induction method is the hardening of steel. One or many induction coils are used to generate and target an alternating magnetic field. This magnetic field produces eddy currents in the metal, which heat the workpiece up to the desired temperature. Immediately after heating, the component then goes through a quenching process using water, oil, or an emulsion. This cools the metal until martensitic transformation occurs, producing a hardened surface that is tougher than the base metal.

After quenching, the steel undergoes tempering, a low-temperature heat treatment process, to reach the desired hardness / toughness ratio. The maximum hardness of a steel grade obtained through the hardening process gives the material a low toughness. Treating the steel through tempering reduces the hardness in the material and increases its toughness.

The hardening depth in the work piece is controlled, very precisely, by adjusting the electrical power output of the induction machine and the frequency of the inductor / coil current. The thickness of the heated layer from the surface of the metal to some point below the surface is inversely proportional to the frequency of the applied alternating current. Higher frequencies produce thinner skins. Case hardening in Faridabad the surface of steel increases the wear resistance of the component without reducing the ductility of the bulk of the material. eldec offers energy sources with the latest converter technology in three frequency ranges:

• Low: 1 – 7 kHz
• Medium: 8 – 40 kHz
• High: 60 – 500 kHz

Induction hardening with SDF

With Simultaneous Dual Frequency, also known as SDF, eldec offers an additional method that is used especially for work pieces with complex shapes. A medium frequency is overlaid with a high one so that both act upon the material simultaneously at a uniform depth. This guarantees the component is heated at a consistent temperature across the entire part to ensure even surface hardness. This application is perfect for the process of manufacturing cogs and gears. Even though the top and bottom of the gear teeth are at different distances from the inductor, a smooth and precise hardness layer can be achieved.