Code No: 07A5EC22 R07 Set No. 2
III
B.Tech I Semester Supplementary Examinations,June 2010
WELDING TECHNOLOGY
Common to Production Engineering, Metallurgy And Material
Technology
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
? ? ? ? ?
1. (a) Explain the factors to be considered in selection of weld joints.
(b) Explain various welding positions with neat sketches. [8+8]
2. (a) What do you understand by the term soldering?
(b) Explain the phenomena
of brazing.
[8+8]
3. (a) Explain the difference between seam welding and spot welding under resistance welding technique?
(b) Why laser welding is used only micro welding applications? [8+8]
4. (a) Describe the functions and characteristics of electrodes? What function do coatings have? How electrodes are classified?
(b)
What
are the similarities and differences between consumable and non con- sumable electrodes?
[8+8]
5. Write
short note on following
weld
cracks:
(a) Chevron cracks
(b) Lamellar cracks.
[8+8]
6. (a) List out the welding
conditions for welding of 5CrMoV steels?
(b)
List out the guidelines for designing welded ultra high
strength steel
struc- tures?
[8+8]
7. (a) Describe the reasons that fatigue generally occur in the heat affected
zones of welds instead
of through the weld bead it self ?
(b)
Why does preheating
the parts to be welded to reduce
the likelihood of crack-
ing?
[8+8]
8. (a) Explain the process of explosive welding for joining of dissimilar metals.
(b)
How do you calculate and control the weld metal
composition resulting from dilution of two different metals?
[8+8]
? ? ? ? ?
1
Code No: 07A5EC22 R07 Set No. 4
III
B.Tech I Semester Supplementary Examinations,June 2010
WELDING TECHNOLOGY
Common to Production Engineering, Metallurgy And Material
Technology
Time: 3 hours
Max Marks:
80
Answer any FIVE Questions
All Questions carry equal marks
? ? ? ? ?
1. (a) Discuss the need for edge preparation in
welding.
(b)
How do you classify
the different weld positions?
Explain them in detail.
[8+8]
2. (a) Which welding process is suitable for welding
of nodular cast
Steels? Explain any one with neat sketch?
(b) Give complete classification stainless steels? [8+8]
3. (a) Give probable causes
of poor quality resistance weld? (b) Give the causes of hot cracking in carbon weld steel?
(c) Name the impurity that may causes
hot cracking in weld steels? [6+5+5]
4. Discuss
the weldability of aluminum
explaining clearly
the chief problems encoun-
tered in its welding.
What fluxes
do you recommend for welding
aluminum? [16]
5. (a) Explain the principle of operation,
equipment and procedure for Manual Metal
Arc Welding.
(b) Explain the modes of transfer of metal during
arc welding process?
[8+8]
6. (a) Explain the principle of brazing with neat sketch.
(b) Differentiate between brazing
and braze welding.
(c) What are the relative advantages of braze welding and fusion welding? [6+5+5]
7. (a) What are the different phases
which can be seen in the microstructure of weldments and Heat affected
Zones of steel welds.
(b) What are phases encountered in the
microstructure of gray cast iron welds?
Explain?
[8+8]
8. (a) What is the effect of metallurgical variable on diffusion welding?
(b) Briefly describe the vacuum fusion bonding of diffusion welding? [8+8]
? ? ? ? ?
2
Code No: 07A5EC22 R07 Set No. 1
III
B.Tech I Semester Supplementary Examinations,June 2010
WELDING TECHNOLOGY
Common to Production Engineering, Metallurgy And Material
Technology
Time: 3 hours
Max Marks:
80
Answer any FIVE Questions
All Questions carry equal marks
? ? ? ? ?
1. (a) Discuss the classification of welding processes.
(b)
Explain the reasons why the cleaning of a joint is important before welding. [10+6]
2. (a) Write
the advantages and limitations
of spot welding?
(b) Explain the important applications
of spot welding. [10+6]
3. (a) Describe the welding
consideration for cast iron? (b)
Explain the following:
i. Buttering
ii. Studding.
[8+8]
4. (a) What is distortion?
Explain its significance in welding?
(b) Explain the structure of Heat Affected Zone in hardenable steel? [8+8]
5. (a) Name
the various shielding gases used in inert gas arc welding methods.
Dis-
cuss the relative merits and demerits
of each one it?
(b) Compare and contrast TIG and MIG welding processes? [8+8]
6. (a) What
is wettability? How the wetting behavior of material
against a particular substrate is
determined?
(b)
How the high electrical and thermal
conductivities
of copper and copper alloys have effect on their weldability? Explain.
[8+8]
7. (a) What would be the heating situation when TIG welding of aluminum with positive electrode?
(b)
State
the
problems
containing likely to be met in
trying to weld an alloy containing
one relatively
low melting
temperature constituents and with a wide solidification range
of temperature?
[16]
8. (a) What are
the factors to be considered in selecting a solder alloy?
Name any
two soldering alloys.
(b) Explain infrared
brazing process with neat sketch. [8+8]
? ? ? ? ?
3
Code No: 07A5EC22 R07 Set No. 3
III
B.Tech I Semester Supplementary Examinations,June 2010
WELDING TECHNOLOGY
Common to Production Engineering, Metallurgy And Material
Technology
Time: 3 hours
Max Marks:
80
Answer any FIVE Questions
All Questions carry equal marks
? ? ? ? ?
1. (a) In what way does laser butt welding resembles plasma
arc welding?
(b) What happens during
the hold time of spot weld? [8+8]
2. What are
the various types of welding joints?
How are they classified? Explain
all of them with neat sketches. [16]
3. (a) State the possible causes for cracking
of welded joints
in carbon
steel, and explain how this effect may be avoided.
(b) State the precaution which should be taken
to minimize
cracking. [8+8]
4. (a) Describe oxy-acetylene
welding of copper with neat sketch.
(b) Describe arc welding of copper with neat sketch. [8+8]
5. Explain the following:
(a) Weldability of arc welded
maraging steels
(b) Weldability of white cast iron.
[8+8]
6. (a) How the diameter
of the electrode determines
the current required?
(b) Write short
note on the AC power sources
of arc welding. [8+8]
7. (a) Discuss post heat treatment methods for weldments.
(b)
Explain the microstructural changes
taking place due to exposure to thermal effects in different parts of weldments. [8+8]
8. (a) Explain why primers are used in adhesive bonding process? What are different types of adhesives used?
(b)
What
are
important characteristics of adhesives used
in
adhesive bonding process? [8+8]
? ? ? ? ?
4
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