FORGING AHEAD WITH VEL INDUCTION HEATING

1. What can be done to increase production at the press ?
2. What can be done to increase the overall efficiency of the entire installation?
3. How can constant temperature be achieved?
4. What contribution can be made to improved quality of the forging ?
5. How can surface deterioration be minimized?
6. What can be done to save Forge shop space?
These are the usual headache of old forge shop floor management. Here is the cure for all

Tempo of working:

In a Forge shop with a bulky fuel fired furnaces and its accessories occupying most of the space available and in an atmosphere of noxious fumes and gas, in a strength sapping radiant heat, a furnace man extracts the billet, not necessarily at desired temperature. With variation in billet temperature, the forging cycle varied resulting in uneven 'tempo'.

Press Never Hungry :

Fuel fired furnaces heats less thoroughly, long volume of air circulates. Heat goes not only into the billets but also into the walls of heating chambers and through the often open furnace doors. This is inefficient way of using energy. On the other way only the billets gets heated by Induction Heating which is the most efficient method of heating . The Induction Heater has excess heating capacity which makes the forging press never 'hungry'.

Pace Maker :

Production output depends to a large degree upon the dexterity of mill team and their ability to maintain set time for each work piece. The precision of Induction Heating and repeatability of results allow fully heated billets to be discharged at regular intervals. Psychologically it is know that the pressure of a pace maker is beneficial to steady production thus synchronizing speed of heating to the rhythm of forging press.

Quality at Ease :

The billet reaches different amounts of heat according to their position and the quality of billets in the chamber. This amounts to bad quality forging. But uniform temperature distribution in billet and repeatable heat cycle by Induction Heating give high quality, best precision forgings without much effort.

Operation with pleasure :

For fuel fired furnaces lengthy start up and shut down procedures are required. safety equipments tends to become more complex with elaborate flame failure protection and automatic shut down in event of excess fuel or air supply pressure variation. Accuracy of temperature control, repaid start up and flexibility in allowing immediate adjustment of billet temperature coupled with the excellent working environment and economy of space have proved overwhelming advantages over alternatives.

Comfortable working :

Induction Heating process avoids discharging the products of combustion into shop, thereby giving rise to a cleaner working environment and since there is little thermal radiation form the casing of the heater plant, operator can work comfortably in its immediate vicinity.

Easy Handling :

Induction work station can installed very near the press thus carrying hot billet to a large distant is avoided.

Automation :

Induction Heater can be easily attached to any work handling system and whole process can be automated.

Healthy Environment :

There is no Air Pollution problem with Induction Heating. There is no water pollution also because the system requires very clean treated cool water and a closed loop water system is installed . The operation of Induction Heater is silent. Disappearance of untidy condition accompanying bulky gas or oil furnace gives clean and spacious environment for working. There is little thermal radiation form Induction Heater, so plant operators can work comfortably in its immediate vicinity.

Safety :

Induction Heaters have no inherent explosion risk, and the comparatively simply and well proved, techniques of interlocking access panels adequately meet safety requirement. There is no risk of burn from furnace casing.

Solves Fuel Crisis :

Through fuel fired furnaces directly convert fuel to heat, this has very low overall efficiency compared to fuel -electricity-induction heat system. 'convert to electricity to conserve energy' is the best way. Induction Heaters gets supply form hydroelectric or nuclear power station, which save diminishing fossil fuels. Induction Heater does not waste energy during non operation hour like lunch break or press held up. It can be used in peak hours when utility company has excess available .

METALLURGICAL ASPECTS :

Higher power concentration of Induction Heating result in very short heating time and easily controllable to comply with given requirement. This avoid oxidation of the billets and there is no scaling. Decarborising is minimum. Extremely short heating time, therefore there is no course grain formation and annealing. There is no overheating and no exclusive time. Induction Heater gives uniform heating condition for each work piece even for steels requiring a particular temperature program.

Clinking :

When the surface is heated faster, the mechanical stress development. Due to this it may crack the work piece. This is some time known as 'Clinking usually occurs in lower temperature range (up to 300 °C). Low carbon steel seldom gives trouble in this aspect but other end of the scale high carbon and chromium steel are very sensitive. Induction heating generate heat within the surface of the work piece and this causes less stress or possible damage to the internal metal structure This is not so easily attained if heat is fed directly through the surface as in the case of fuel fired.

Reducing atmosphere while heating :

It is simplicity itself to inject a suitable gas atmosphere into the induction coil .This will minimize the scale formation still further. In any event without this the limited amount of oxygen within the narrow confines of coil lines is readily consumed at the temperature involved, thus providing inert heating condition.

SAVING IN MATERIAL :

The metal loss due to oxidation is about only 0.5 %. compared to 3% in oil fired furnace As there is no scaling or decarborisation of surface in Induction Heating a closed tolerance can be achieved in forging. So the total metal savings amounts to 10% to 15%

Saving in Machining :

As per D.S.4659 decarborisation allow in tool steel is 0.5%. But decarborisation is about 1.6 mm in fuel fired furnace. So you have to forge in large size and machine decarbed layer. The machining process can be completely avoided by induction heating because decarborisation by Induction heating is only 0.0 25 mm.

Saving in die shop floor space :

It economises valuable floor space near the line by removing all possible ancillary equipment and service to a separate environment and using every inch of space for process of forging.

Saving in man power and maintenance:

Induction Heating allows complete automation . Thus the number of personnel required to operate an installation can be reduced accordingly. It is also not necessary for operating personnel to possess high degree of skill. This assumes, of course, that maintenance staff are top rate-men . However maintenance is generally less than for fuel fired furnace. A fraction of less than 1% downtime is not unusual in Induction Heating.

Saving in Inspection Time :

Selective inspection has been substituted for 100% inspection.

Saving in Energy :

Lunch break and Tea break can be given to energy consumption and there is no wastage of heat when Induction heater is used. The electrical consumption of heating is 375 to 400 KW/ton compared to 120 to 140 liter/ ton or 100 to 120 m3 /ton in fuel fired furnace.

Saving in Management Time:

The trouble spots causing bad heating and bad production run are eliminated .

Investment Justified :

The rhythmical working pattern helps to stem the dissipation of labour but additional directly attributable benefits, such as higher production , better life quality of forging fully justifies the investments in this method of heating.Induction Heating is the cure all for all problems.

INDUCTION HEATING IS CURE FOR ALL PROBLEMS