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