Induction forging and induction hot forming refer to the use of an induction heating machine to pre-heat metals prior to deformation using a press or hammer. Typically metals are heated to between 1,100 and 1,200 °C (2,010 and 2,190 °F) to increase their malleability and aid flow in the forging die.
Metal induction forging and induction hot forming are excellent induction heating applications. Industrial forging and hot forming processes involve bending or shaping a metal billet or bloom after it has been heated to a temperature at which its resistance to deformation is weak. Blocks of non-ferrous materials can also be used.
Induction heating machines or conventional furnaces are used for the initial heating process. Billets can be transported through the inductor via a pneumatic or hydraulic pusher; pinch roller drive; tractor drive; or walking beam. Non-contact pyrometers are used to measure the billet temperature.
Other machines such as mechanical impact presses, bending machines, and hydraulic extrusion presses are used to bend or shape the metal.
The approximate hot forming temperatures of the most commonly used industrial materials are:
• Steel 1200º C • Brass 750º C • Aluminium 550º C
Total Forming Applications
Induction heating machines are commonly used to heat steel billets, bars, brass blocks, and titanium blocks to the proper temperature for forging and hot forming.
Partial Forming Applications
Induction heating is also used to heat parts such as pipe ends, axle ends, automotive parts, and bar ends for partial forming and forging processes.
The Induction Heating Advantage
When compared to conventional furnaces, induction heating machines for forging offer significant process and quality advantages:
- Much shorter heating times, minimizing scaling and oxidation
- Easy and accurate temperature temperature control. Parts at temperatures outside specifications can be detected and removed
- No time lost waiting for the furnace to ramp up to the required temperature
- Automated induction heating machines require minimal manual labor
- Heat can be directed to one specific point, which is highly important for parts with only one forming area.
- Greater thermal efficiency – heat is generated in the part itself and does not need to be heated in a large chamber.
- Better working conditions. The only heat present in the air is that of the parts themselves. The working conditions are much more pleasant than with a fuel furnace.