INDUSTRIAL
TRAINING REPORT
Training
Taken at:
LAKSHMI
MACHINE WORKS Ltd, COIMBATORE
&
SIMTA Ltd,
COIMBATORE
SUBMITTED
BY
SATHYA PRAKASH.G
2K2-177
DEPARTMENT OF MECHANICAL ENGINEERING
NATIONAL INSTITUTE OF TECHNOLOGY
KURUKSHETRA
CORE MAKING:
Cores are forms that are
placed into the mould to create the interior contours of the casting. These
cores are a sand mixture, typically made from sand combined with water and
organic adhesives (binders). The sand cores were then baked to form the solid
core, the baking process necessary to make the cores strong, yet collapsible,
so they could be easily removed later on from the finished casting by severe
shaking.
Since
cores are also made in moulds, they require another pattern and the creation of
their own mould, which in this case is called a "core box". The core
pattern is made in the same way as the casting pattern, but the core box is
created from a durable material like metal or wood so it can be reused a number
of times. Obviously, since the cores are made of sand, the core moulds cannot
also be made of sand.
MOULDING:
Moulding is the multi-step process in which the moulds for our cast part are actually created. In typical horizontal casting, the mould is contained in a two-piece frame or support, called a "flask". The upper portion of the flask is called a "cope" and the lower portion is the "drag". First, moulding sand is packed into a flask around the pattern that was previously made. After the pattern is gently removed, gating and runner arrangements are positioned in the drag half (lower half) of the mould cavity and "sprue" is placed in the cope portion.
The sprue is necessary to make the
opening in the mould in order to be able to pour the molten metal into the
mould, and gating systems are necessary in order for the molten metal to flow
into the mould cavity evenly and correctly. Cores are also placed in the drag
portion of the mould if they are needed to form hatch openings, etc. To finish
the mould, the cope (top) section is placed onto the drag section, and the
mould clamped together and the sprue is then removed.
MELTING:
Melting
and pouring begins the preparation of the metal for casting, converting it from
its solid form to a liquid state, generally in a blast furnace at a controlled
temperature. The temperature maintained is around 750° C. The molten metal is then transferred to
the moulding area of the foundry using a huge ladle, where the metal is then
poured into the moulds through the sprue opening. After the steel has cooled
and solidified, the moulds are vibrated to break them up and the sand is
removed from the casting, a process often called "shakeout".
Melting Procedure:
1. First of all, weigh the scraf according to the guidance of the supervisor.
2. Visually inspect the empty furnace.
3. If there are no deformities in the furnace lining, put 150 kg of the scraf iron pieces in the bottom of the furnace.
4. Switch on the furnace.
5. After the melting of the charge put also the remaining charge into the furnace and melt down each of the charges.
6. After the charge melts down fully, remove the slag present using the slag spoon.
7. Put the weighed alloy particles into the molten metal and then mix them thoroughly.
8. Using a sample spoon, take out a sample of molten metal and test it chemically.
9. Submit the sample to the lab.
10. After getting the lab results, mix the alloy materials into both.
11. Increase the alloy bath temperature up to the desired level.
12. By placing aluminium piece at the tip of the NS rod and soak it into the furnace again and again.
13. When the super wiser orders, tilt the furnace to a side and take the molten metal bath into ladle place in the crane operator.
14. As according to the order of the super wiser, put the de-oxidizing particles into the ladle.
CASTING:
Casting is the process in which molten
metal is poured into a mould and allowed to solidify to form an object. The
object that results from this process is also called a "casting".
Most of the metal casting used for making parts is done using the sand casting
method. The sand was used to define the cavity space inside the mould. In
addition, the sand was used to make any cores that were contained in the mould.
After it is poured, the molten metal solidifies in the cavity between the
interior of the mould and the exterior of the core; the core was then removed
to produce the hollow cast object.
The molten metal taken in the ladle is poured into the mould cavity by means of the following procedure.
1. First of all, check the pouring temperature before pouring.
2. Remove the slay in the ladle.
3. Pour the molten metal exactly in the down sprew.
4. Remove the escaping gases using the fire flames.
5. The number of castings inside which the molten metal was poured, should be noted down.
6. We have to place the number tag above the vent sprew after the metal is poured in.
If we find any mistakes, then we
should report to the section head.