This document discusses defect analysis of orbital TIG welding. It introduces orbital TIG welding and describes how it is used to join circular objects like tubes and pipes. Common defects that can occur include porosity, lack of fusion, and lack of penetration. The document focuses on analyzing lack of fusion and proposes solutions to reduce it, such as increasing current input, proper wire feed, and maintaining distance between workpiece and wire. Non-destructive testing methods like industrial radiography are used to identify internal defects. The results show that modifying the welding program reduced the rate of lack of fusion defects.

1. DEFECT ANALYSIS OF
ORBITAL TIG
WELDING
SASIKUMAR NATARAJAN 1

2. INTRODUCTION OF ORBITAL TIG WELDING
Orbital welding is the first
choice for the joining of tubes and
pipes. The welding torch in most
cases, the TIG-welding process is
used travels around the tubes to be
joined, guided by a mechanical
system. This process only
recommended for circular objects.
SASIKUMAR NATARAJAN 2

3. ABSTRACT
In current scenario is one of the major
concern in industries to reduce the defect and
wastage. In this project of Orbital TIG Welding we
studied and analyzed the NDT methods.
After studying this method and process will
occur defects like Porosity, Lack Of Fusion, Root
Penetration and etc., So We have chosen the project
to reduce the maximum number of defect in an
Orbital TIG Welding.
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4. LITERATURE REVIEW
Orbital TIG Welding is an effective process
for joining of circular components on carbon steel
and Alloy Steels like as Grade C, Alloy steels T11,
T12, SS437, SS304.
But this method of Orbital TIG Welding
requires development of torch design, wire feed
mechanism and welding procedure for preventing
sort of weld defects.
Use of optimized welding parameters for
different thickness of tubes/pipes and influence of
welding speed on distortion of pipe.
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5. PROBLEM AND DESCRIPTION
In Orbital TIG Welding Technique is used to
joining of circular components which make quick
and good finish. But this method makes defect on
the process like Arc Strike, Lack of Fusion, Lack of
Penetration, Porosity and etc.,
The major defect is Lack Of Fusion. This
problem will occurs when the work piece does not
receive adequate heat supply and Fusion.
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6. WELDING CYCLE
TOP - 0 to 90 degree is flat root pass
RIGHT - 90 TO 180 degree is descendant vertical pass
BOTTOM -180 to 270 degree is overhead pass
LEFT - 270 to 360 degree is ascendant vertical pass
0 90
180270
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7. NON DESTRUCTIVE TESTING
Non Destructive Testing is a testing
technology based on applied physics and method of
testing materials for crack or flaws without
damaging their physical structure. There are two
types of NDT Methods,
Method for detection of internal defects
Method for detection of surface defects
In our project we analyzed Industrial
Radiography method in Non Destructive Testing.
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8. INDUSTRIAL RADIOGRAPHY
Industrial Radiography is a method of Non
Destructive Testing. It can be examined to verify
the internal structure and integrity of the specimen.
This Radiography Testing can be performed
utilizing the X-Rays.
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9. LACK OF FUSION
In welding method incompletely fused spots
are called Lack of Fusion. A weld can lack union
with the parent metal or with a previous weld bead
which causes improper fusion between weld and
parent metal.
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10. RESULT AND DISCUSSION
Identified Lack Of Fusion in the project, hence
decided to change the welding program to reduce
the Lack Of Fusion by following steps,
REDUCING THE LACK OF FUSION
1. To increase the current input
2. Proper wire feed
3. Keep the 2mm distance between the work piece
and wire feed.
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11. SOLUTION
Based on December – 2018 report, Lack Of Fusion
for ‘SA106 Grade C’ material in Orbital TIG welding
defects were 68%.
We changed the welding program for ‘ SA106
Grade C ’ material in Orbital TIG welding. So that the
defect of Lack Of Fusion was reduced 42%.
With Defect Without Defect
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12. CONCLUSION
Our project mainly focused on the reduction of Lack Of
Fusion in orbital TIG welding process. The existing method
welding program has some errors and has some incorrect
data. But the alternate solution had reduced the Lack Of
Fusion, which is increasing the current input and locating the
proper wire feed by applying the alternate program for
welding the ‘SA106 Grade-C ‘ material.
1. Reduction in lack of fusion will decrease the production
cost upto 50%.
2. Energy saved, Less operator fatigue and Total cycle time
reduction.
3. Orbital TIG welding increases equipment life and effective
material utilization.
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