Download GTU (Gujarat Technological University Ahmedabad) B.Tech/BE (Bachelor of Technology/ Bachelor of Engineering) 2020 Winter 7th Sem 2172111 Advances In Welding Metallurgy Previous Question Paper
Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE- SEMESTER?VII (NEW) EXAMINATION ? WINTER 2020
Subject Code:2172111 Date:21/01/2021
Subject Name:Advances in Welding Metallurgy
Time:10:30 AM TO 12:30 PM Total Marks: 56
Instructions:
1. Attempt any FOUR questions out of EIGHT questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
MARKS
Q.1
(a)
State the requirement of advances in welding Power
03
sources giving suitable examples.
(b)
Enlist Process variables of GTAW process and discuss
04
Why high frequency arc starting is required in GTAW
Welding?
(c)
Draw schematics comparing DCEN, DCEP and AC
07
welding characteristics with 1. Heat balance 2.
Penetration characteristics 3. Oxide cleaning action and 4.
Electrode size and current caring capacity.
Q.2
(a)
Calculate heat Input for SMAW Process Current- 150 A,
03
Voltage- 22 V, Travelling Speed- 150 mm/min, process
efficency 60%.
(b)
Critically Compare Argon, Helium Argon-helium
04
mixtures and CO2 shielding gases.
(c)
Justify the following development with filler
07
Wire/Consumable a) Addition of Fe Powder in SAW Flux
b) Rutile based Flux coating in SMAW Electrodes c)
Titanium Boron micro alloying in SAW Wire d) Low
hydrogen electrodes.
Q.3
(a)
Explain Specifications of following Consumables : -
03
(1) E 6013 (2) F70A2-EL8 (SAW FLUX + WIRE) (3)
ER 70 -S6 / ER 70-S2 (4) E71T - 1
(b)
Classify the Low hydrogen electrodes and state their
04
requirements.
(c)
Enlist the various parameters of Friction Stir Welding and
07
state the merits-demerits and application.
Q.4
(a)
Draw schematic of various modes of metal transfers in
03
GMAW.
(b)
Evaluate Flux core wire gives higher penetration
04
compared to solid wire.
(c)
Draw schematic of plasma key hole welding and state the
07
applications of this process.
Q.5
(a)
Differentiate between agglomerated and fused fluxes used
03
for SAW Process.
(b)
State the applications of Friction Stir surfacing.
04
(c)
Explain Narrow Gap Welding Processes for High
07
Thickness joints with schematics. How can NGW joints
save consumable, time and labour? Justify
Q.6
(a)
What are the benefits of Pulse TIG welding technology?
03
Only draw pulse wave form.
(b)
Why Ac welding is preferred for welding of Aluminium
04
/aluminium alloys ?
(c)
Explain the process of Activated Flux TIG Process &
07
state the merits & demerits. How much plate thickness it
can weld in one pass?
Q.7
(a)
Draw schematics of Hot Wire TIG Welding Process the
03
state the benefits of this process.
(b)
Low heat input and less weld metal volume is preferred to
04
obtain sound mechanical properties of the weld? Justify
with suitable example
(c)
What is Cold Metal Transfer Technology? What are the
07
process benefits of this process?
Q.8
(a)
Enlist Salient features of intelligent welding Power source
03
system based on Fuzzy logic and Artificial intelligence.
(b)
Differentiate between self-shielded and externally
04
shielded electrodes.
(c)
Write short note on (i) Robots in Welding automation (ii)
07
Modelling and simulation of welds
*********************************
This post was last modified on 04 March 2021