P P R R O O J J E E C C T T R R E E P P O O R R T T AT R R A A I I L L C C O O A A C C H H F F A A C C T T O O R R Y Y , , K K A A P P U U R R T T H H A A L L A A WITH EFFECT FROM 07-05-2012 TO 30-06-2012 SUBMITTED BY- NAME- BRANCH- ROLL NO- UNIV ROLL NO-
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PPRROOJJEECCTT RREEPPOORRTT
AT
RRAAIILL CCOOAACCHH FFAACCTTOORRYY,, KKAAPPUURRTTHHAALLAA WITH EFFECT FROM 07-05-2012 TO 30-06-2012
SUBMITTED BY- NAME- BRANCH- ROLL NO- UNIV ROLL NO-
INDEX
S. NO TOPICS PAGE NO. REMARKS
1.
ACKNOWLEDGEMENT
1
2. ABOUT RCF
2-3
3. TIG WELDING
4
4. MIG WELDING
5
5. SUBMERGED ARC WELDING
6
6. GAS WELDING
7
7. WELD DEFECTS
8-14
8. TYPES OF ELECTRODES
15
9. TECHNICAL TRAINING CENTRE
16
ACKNOWLEDGEMENT
With profound respect and gratitude, I take the opportunity to convey my thanks
to complete the training here.
I do extend my heartfelt thanks to Mr. R. K. SHARMA head of TTC
(Technical Training Center) and Mr. R.C. NASA head of Welding Workshop
for providing me this opportunity to be a part of this esteemed
organization.
I am extremely grateful to all the technical staff of RAIL COACH FACTORY,
Kapurthala for their co-operation and guidance that helped me a lot during
the course of training. I have learnt a lot working under their guidance and I will
always be indebted of them for this value addition in me.
ABOUT RCF
Established in 1986, RCF is a coach manufacturing unit of Indian Railways.
RCF has already carved a niche in the industrial scenario of the country at large
and Indian Railways, in particular. It has manufactured around 16000 passenger
coaches of 51 different types including Self Propelled passenger vehicles which
constitute over 35% of the total population of coaches on Indian Railways.
RCF is equipped with a state-of-the-art CAD centre and CNC machines to
undertake design and manufacture of Bogies, Shell (both with Stainless Steel
and Corten Steel), FRP interiors as per customer’s requirement. The state-of-
the-art manufacturing facilities and processes have enabled RCF to achieve
excellence in Design, Development, Manufacture, Installation and After-sales
service of Railway coaches with a view to ensure enhanced satisfaction of the
Rail customer.
RCF has a strong tradition of innovating and developing new products and has a
very wide manufacturing range of products which includes:-
• 1st AC Sleeper Coach (BG)
• 2 Tier AC Sleeper Coach (BG, MG)
• 3 Tier AC Sleeper Coach (BG)
• AC Inspection Coach (BG)
• AC Chair Car, Executive Class & Economy Class (BG, MG)
• AC Buffet Car (BG)
• AC Power Car (BG)
• MG Diesel Electrical Multiple Units
• Main Line Electrical Multiple Units (BG)
• Non-AC Sleeper Class Day Coach (BG)
• Non-AC General Coach (BG/MG)
• Non-AC Luggage-cum-Brake Van (BG/MG)
• Refrigerated Parcel Van (BG)
• Non AC Inspection Coach (BG)
• High Capacity Parcel Van (BG)
• Accident Relief Train (BG)
• Post Office Coach (BG)
• Coaching Container Flats (BG)
• Double Decker Coach (BG)
• Non-AC Day Coach (BG)
Fig:- Rail Coach Factory, Kapurthala
TIG WELDING
In the TIG (tungsten inert gas) welding process, an essentially non-consumable
tungsten electrode is used to provide an electric arc for welding. A sheath of
inert gas surrounds the electrode, the arc, and the area to be welded. This gas
shielding process prevents any oxidization of the weld and allows for the
production of neat, clean welds.
TIG welding differs from MIG (metal inert gas) welding in that the
electrode is not consumed in the weld. In the MIG welding process the
electrode is continuously melted and is added into the weld. In TIG welding, no
metal is added unless a separate filler rod is used.
TIG welding can be performed with a large variety of metals. The two
most commonly TIG welded metals in the PRL are steel and aluminum. Steel is
relatively easy to TIG weld and it is possible to produce very tight, neat welds.
Aluminum takes a little more skill, and one should have at least a little bit of
experience in welding steel before making the transition to aluminum.
However, the basic technique is essentially the same and most people can make
the jump to aluminum fairly easily.
TIG welding is an extremely powerful tool. With a little practice, it is
possible to make beautiful welds much more quickly and easily than with oxy-
acetylene welding. It also the only option currently available in the shop for
welding aluminum. Put in a little time, and you will be rewarded in spades.
MIG WELDING
MIG welding is an abbreviation for Metal Inert Gas Welding. It is a process
developed in the 1940’s, and is considered semi-automated. This means that
the welder still requires skill, but that the MIG welding machine will
continuously keep filling the joint being welded.
MIG welders consist of a handle with a trigger controlling a wire feed, feeding
the wire from a spool to the weld joint. The wire is similar to an endless bicycle
brake cable. The wire runs through the liner, which also has a gas feeding
through the same cable to the point of arc, which protects the weld from the air.
MIG welding is most commonly used in fabrication shops where production is
high, and the possibility of wind blowing away your gas shielding is unlikely.
SUBMERGED ARC WELDING
Submerged arc welding (SAW) is a common arc welding process. Originally
developed by the Linde - Union Carbide Company. It requires a non-
continuously fed consumable solid or tubular (flux cored) electrode. The
molten weld and the arc zone are protected from atmospheric contamination
by being “submerged” under a blanket of granular fusible flux consisting of
lime, silica, manganese oxide, calcium fluoride, and other compounds. When
molten, the flux becomes conductive, and provides a current path between the
electrode and the work. This thick layer of flux completely covers the molten
metal thus preventing spatter and sparks as well as suppressing the intense
ultraviolet radiation and fumes that are a part of the shielded metal arc
formation of martensite as the weld cools. The cracking occurs in the heat-
affected zone of the base material. To reduce the amount of distortion and
residual stresses, the amount of heat input should be limited, and the welding
sequence used should not be from one end directly to the other, but rather in
segments.
Cold cracking only occurs when all the following preconditions are met:
susceptible microstructure (e.g. martensite) hydrogen present in the microstructure (hydrogen embrittlement) service temperature environment (normal atmospheric pressure): -100 to
+100 °F high restraint
Eliminating any one of these will eliminate this condition.
Crater crack
Crater cracks occur when a crater is not filled before the arc is broken. This
causes the outer edges of the crater to cool more quickly than the crater, which
creates sufficient stresses to form a crack. It may form a longitudinal or
transverse crack or form multiple radial cracks.
Fusion-line crack
Creep crack growth and fracture toughness tests were performed using test
material machined from a seam welded ASTM A-155-66 class 1 (2.25Cr-1Mo)
steel steam pipe that had been in service for 15 years. The fracture morphology
was examined using SEM fractography. Dimpled fracture was found to be
characteristic of fracture toughness specimens. Creep crack growth generally
followed the fusion line region and was characterized as dimpled fracture mixed
with cavities. These fracture morphologies were similar to those of an actual
steam pipe. It was concluded that creep crack growth behavior was the prime