10
■
Operating at low temperature
Generally, due to the structure of electric furnaces, temperature control and temperature distribution
tend to worsen as the operating temperature decreases due to control methods. When used below
300
℃
, the lower the temperature, the greater the tendency. Therefore, adjust the set temperature
according to the actual firing condition.
■
Heating element
The heating element used in our electric furnace is a heating element for high-temperature furnaces
with a maximum operating temperature of 1400
℃
. In particular, this material has extremely good
resistance to oxidation in the atmosphere, making it suitable for various electric furnaces as well as
various
high-temperature
furnaces and electric heating equipment.
・
Effects of various atmospheric gases
a
）
Atmosphere/Nitrogen
It can be used without problems. Especially in the air above 800
℃
, a protective film consisting of
AL
2
O
3
is formed on the heater surface, so it is recommended to regularly bake in air.
b
）
Carburizing atmosphere
The
protective
film
of
AL
2
O
3
formed on the surface of the heating element prevents carburization
inside and shows good high temperature corrosion resistance. Before using the heating element
in the carburizing atmosphere, preheat it in the air (at 800
℃
or higher for about 5 hours) and
generate a protective film of AL
2
O
3
on its surface to prevent carburization inside the heating element
Lengthen.
c
）
Other
Any substance that inhibits the formation of the AL
2
O
3
protective film formed on the surface of the
heating element or that reacts with the protective film to lower the melting point is harmful to the
heating
element.
●
S (sulfur)
Use in an atmosphere containing H
2
S or SO
2
is not preferable because it reacts with
S to lower the melting point.
●
Halogen/salt
Halogen elements such as Cl and F and salts of alkali metals such as Na and K are
all harmful because they hinder the formation of protective film.
・
Operating at low temperature
When used in a temperature range of 500
℃
or lower, the heater may break due to the carbon that comes
out of the heat-treated product adhering to the heater surface (shooting phenomenon). If the inside of
the furnace is dark, carbon may be attached, so bake it at 800
℃
or higher for about 1 hour. A long burning
life can be expected as the carbon burns and an oxidation protection film is also formed on the heater
surface.
■
Structure of the furnace door
The furnace door of this machine has a structure in which the heat insulating material moves slightly
back and forth. This is to ensure that there is no gap between the furnace lid and the furnace lid even
after many years of use, and the furnace lid is pressed with a spring when the door is closed, so that
the furnace lid is always in close contact. It is supposed to be. If you open the door and press the
furnace lid (insulation part), it will dent in the back, but this is not a malfunction.
■
Transportation
When transporting this product for movement or repair, do not put the hearth plate, objects,
etc. in the furnace. Also, remove the exhaust port plug and exhaust guide. It damages the
furnace during transportation.
CAUTION
CAUTION
Summary of Contents for 1500-Plus
Page 2: ......
