Time Temperature Analysis of Welding Process

1. Time Temperature Analysis
of
Welding Processes
Prepared by:
Kaustav Datta (12BME010)
Kawan R. Jain (12BME019)
8th Semester B.Tech.,
Dept. of Mechanical Engineering,
School of Technology,
Pandit Deendayal Petroleum University,
Gandhinagar
Guided by:
Dr. Vishvesh J. Badheka
Associate Professor
Department of Mechanical Engineering,
School of Technology,
Pandit Deendayal Petroleum University,
Gandhinagar

2. Contents discussed during Mid-Semester Review
• Project title and Introduction
• Literature Survey – Why Time Temperature Analysis
• Literature Survey – GMAW (Process & its Advantages)
• Literature Survey – FCAW (Process & its Advantages)
• Literature Survey – MCAW (Process & its Advantages)
• Method of Experiment
• Materials and Tools
• Experimental Method
2

3. Figure 1. Process Schematic Diagram for MIG/FCAW/MCAW
Source: AU : IPRM 2007 : Section 4 : Welding Processes

4. Materials and Tools
4
Gases used:
Argon (80%)
CO2 (20%)
Kempact Pulse 3000MVU
Kemppi K5 MIG/MAG
welder
Software: Pro Weld Data v
3.17
Metal Consumables:
GMAW Wire
FCAW Wire
MCAW Wire
Figure 2. Electrode Gun used for MIG/FCAW/MCAW
Source: AU : IPRM 2007 : Section 4 : Welding Processes

5. Previous Work
• We have learned about all the 3 Welding Processes, i.e., GMAW, FCAW, MCAW
thoroughly & understood the welding operation as well as their advantages
individually.
• Later we also discussed several differences between the 3 Processes, and observed
Economic Advantage of Cored Tubular Wire over Solid Wire Use.
• The Method of Experiment has been Covered earlier itself.
• After Getting the Samples from the Welding, We performed several Tests to find
out Few properties of the Weld Metal.

6. Post Experiment
All Samples are properly cleaned by using brushes.
Further, Two samples are cut from Between of size 10mm*100mm*10mm, for further inspection &
testing purposes.
Above step is repeated for All 3 Processes.
Figure 4. Flux Cored Wire (Fcaw), SampleFigure 3. Test Sample cutting under Band Saw Machine.

7. Process Parameters & Their Effects
In arc welding processes, a number of welding parameters exist that can affect the
size, shape, quality and consistency of the weld. Producing a weld bead of the right
size, shape and depth involves many variables. Few of them are:
1. Amperage
2. Arc Voltage
3. Travel Speed
4. Arc Length
5. Work Angle
Our main objective was to find out the Heat Input or Power requirements for three
different welding processes, i.e, GMAW, FCAW and MCAW, so we have kept all
these parameters constant for our experiment work.

8. Table1 Process Parameters used in the Experiment
GMAW FCAW MCAW
Amperage 198 A 191 A 186 A
Arc Voltage 27.7 V 27.9 V 28 V
Travel Speed 220 mm/min 220 mm/min 220 mm/min
Arc Length 2 mm 2 mm 2 mm
Work Angle 90° 90° 90°
Total Energy Used 443 KJ 406.7 KJ 420.3 KJ
1. Amperage – Higher the Current, Deeper the Penetration
2. Arc Voltage – Higher Voltage leads to more wider & flat Bead
3. Travel Speed – Faster the travel speeds, results in narrower beads with less
penetration.
4. Arc Length – Size of the Electrode and Amperage Increases, Arc Length
Increases

9. RESULTS AND DISCUSSION

10. Contents to be discussed here….
1. Time Temperature Variation for GMAW, FCAW, MCAW Processes.
2. Heat Input Calculations and Plots.
3. Macrostructure Testing & Imaging.
4. Weld Dimensional Analysis.
5. Microstructure Images and Analysis.
6. Microhardness Test Results.
7. Conclusion.
8. References.

11. Table 2 Time-Temperature data of the Experiments
Time (s) Temperature (°C)
GMAW FCAW MCAW
0 14 23 20
2 14 23 21
4 14 23 21
28 17 33 33
30 18 41 36
36 22 57 69
38 33 80 97
40 48 133 144
42 92 211 213
44 116 272 263
46 178 306 284
48 234 319 299
50 259 330 308
52 285 337 315
54 298 340 318
56 309 341 320
58 315 341 321
62 318 340 321

12. Time Temperature Variation For Gmaw
318 °C
0
50
100
150
200
250
300
350
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70
Temperature(°C)
Time (s)
TEMPERATURE VS. TIME PLOT FOR GMAW
Temperature
Table 3 Time-Temperature data from Software for GMAW
Weld name Date Start time Arc time Av.Current(A) Av.Voltage(V) Av.Wfs(m/min) Energy used(kJ)
W0001 1/26/2016 1:10:13 PM 01:21 198 27.7 7.9 443.3
Figure 5. Temperature vs. Time plot for GMAW

13. Time Temperature Variation For Fcaw
Table 4 Time-Temperature data from Software for FCAW
Weld name Date Start time Arc time Av. Current(A) Av. Voltage(V) Av.Wfs(m/min) Energy used(kJ)
W0002 2/5/2016 3:44:57 PM 01:17 191 27.9 7.9 406.7
0
50
100
150
200
250
300
350
400
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70
Temperature(°C)
Time (s)
TIME – TEMPERATURE ANALYSIS OF FCAW
Temperature
342 °C
Figure 6. Temperature vs. Time plot for FCAW

14. Time Temperature Variation For Mcaw
Table 5 Time-Temperature data from Software for MCAW
Weld name Date Start time Arc time Av.Current(A) Av.Voltage(V) Av.Wfs(m/min) Energy used(kJ)
W0003 1/26/2016 2:59:56 PM 01:16 196 28 7.9 420.3
322 °C
0
50
100
150
200
250
300
350
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70
Temperature(°C)
Time (s)
TIME – TEMPERATURE ANALYSIS OF MCAW
Temperature
Figure 7. Temperature vs. Time plot for MCAW

15. Heat Input Calculations And Plots
The Heat Input for an ideal arc welding process is given by:
𝐻𝐼 =
𝑉 × 𝐼 × 60
𝑆
where,
HI = Heat Input
V = Voltage
I = current
S = Welding Speed

16. • For a lower heat input value, it is observed that the FCAW process witnesses the
highest temperature observed during the welding.
• This means that the temperature is raised easily to a higher value for the FCAW
process, as compared to the MCAW and GMAW. Also, higher heat input should
yield better strength/toughness of weld.
• GMAW Process requires Maximum Heat Input among all the three, but still
Maximum Temperature reached is very low compared to others.
Table 6
PROCESS ENERGY USED (KJ) HEAT INPUT CALCULATED
(KJ)
PEAK TEMPERATURE (°C)
GMAW 443.3 438.50 318
MCAW 420.3 416.90 322
FCAW 406.7 410.23 342

17. Macrostructure Testing & Imaging
• To achieve good Microstructure of the sample, we had to achieve Mirror Like
finishing.
• For this purpose, samples were cleaned and then grinded on the Belt Grinder for
the first time to remove any present burrs.
• Later different grades of paper were used on the Paper Grinder Machine to
enhance the quality of the finish.
• After doing this, samples were put in a beaker such that they were completely
submerged in the Etchant.
• The purpose of etching is to optically enhance the microstructural features such as
grain size and phase features. Etching selectively alters these microstructural
features based on composition, stress or crystal structure.
• The most common technique for etching is selective Chemical Etching and
numerous formulations have been used over the years.

18. Fig. 9 Beaker after 12 mins heating Fig. 10 Macrostructure
measurement
Fig 8 Samples being heated at 70°C for 12-15
mins in a beaker

19. • We used a 35% concentrated Hydrochloric Acid (HCl) solution for the etching process, where the
beaker was heated for 12-15 mins at 75°C.
• After this, the samples were washed and cooled down and then observed under a microscope with
magnification 10X to obtain the following Macrostrucural Images and measure the weld
dimensions
Table 4.5Macro Images of the Samples
S1 M1 F1
• The macrostructure images show that FCAW has the least visible depth of weld penetration and
the also the least weld reinforcement.
• We have found visible elongated porosity in the solid wire weld.
• The Weld Heat Affected band is clearly visible in case of solid and metal cored welding and is
obstructed by the elongated porosity in the case of the flux cored welding
Table 7 Macro Images of the Samples

20. Weld Dimensional Analysis
• The weld bead dimensions are measured using a microscope under a 10X
magnification lens at the Metallurgy Laboratory in PDPU premises.
• The following are the weld bead dimension measurements according to the image
attached for reference.
Table 8 Measurement of Weld Bead Width
Sample Name Sample No. D1
(mm)
D2
(mm)
Bead Width
(D2 – D1)
(mm)
Average Bead
Width
(mm)
Solid
S1 2.05 3.15 1.10
1.345
S2 1.45 3.04 1.59
Metal
M1 2.05 3.27 1.22
1.235
M2 2.08 3.33 1.25
Flux
F1 0.55 1.91 1.36
1.380
F2 0.56 1.96 1.40

21. Table 9 Measurement of Weld Reinforcement and Depth of Penetration
Sample
Name
Sample No. H1
(mm)
H2
(mm)
H3
(mm)
Reinforcement
(H2 – H3)
(mm)
Average Reinforcement
(mm)
Depth of Penetration
(H1 – H2)
(mm)
Average
DOP
(mm)
Solid
S1 3.72 3.36 2.92 0.44
0.48
0.36
0.365
S2 3.37 3.00 2.48 0.52 0.37
Metal
M1 3.80 3.37 3.01 0.36
0.37
0.43
0.365
M2 3.73 3.43 3.05 0.38 0.30
Flux
F1 3.14 3.08 2.77 0.31
0.30
0.06
0.070
F2 3.13 3.05 2.76 0.29 0.08
H2 – H1
H3 – H2
D2 – D1
Figure 11. Weld Bead Shape
generated during Welding
http://www.azom.com/article.aspx

22. • As expected, the lower current in the FCAW process is responsible for a lower
DOP amongst the three processes.
• Also, the voltage input is very slightly higher (0.1 V) in case of FCAW and due to
the slight variation, the weld bead width is observed to be maximum where the
Voltage is also maximum.

23. Microstructure Images And Analysis
• For the study of the Micro Structure, we have used an Olympus GX 51
Metallurgical Microscope. For this, we availed the services of Hertz testing Centre
in Vatva, Ahmedabad.
• Optical microscopy revealed that the use of different electrode wires has a
significant effect on the microstructures in the different welded samples.
• In this study, the effects of performing welds using solid, flux and metal cored wires
were examined.
• The comparison of microstructure of the different regions is shown in the table 4.5
for samples S1, F1 and M1 respectively.
• The images were captured at different magnifications of 100X, 200X, 500X and
1000X from which the images taken at 200X and 500X are compared.

24. Table 10 Observation of Microstructures of different regions in the three welds
Region S1 F1 M1
Weld
Zone
(200x)
Weld
Zone
(500x)

25. Table 10 (contd.) Observation of Microstructures of different regions in the three
welds
Region S1 F1 M1
HAZ
(200x)
Base Metal
(200x)

26. • A high heat input gives slower cooling and the grain size in the HAZ can become
very coarse if the temperature is high enough to promote grain growth prior to
transformation.
• GMAW Process required Maximum Heat Input among the three.
• From the microstructural images, we can observe that the grain boundaries are
clearly visible and finer in case of FCAW and MCAW processes as compared to
GMAW process.
• This is justified as the heat input is also lower in case of the cored-wire welding
processes. Also, the finer microstructure leads to a higher hardness value.
• This is verified by the Micro Hardness measurement done thereafter.

27. Microhardness Test Results
• Finally, the Micro Hardness test of the samples was done, for which we have used a
Vicker cum Brinell Hardness Tester BIE / BV-250 SPL.
• For this, we availed the services of Hertz testing Centre in Vatva, Ahmedabad.
Measurement of Micro-Hardness of the different regions is shown in the table 4.6
for samples S1, F1 and M1 respectively.
• The measurements were done using a 1 Kgf force on a diamond shaped indenter.
The table is followed by a comparative graph of the same.

28. Table 11. Micro Hardness (Brinell) Data for the weld samples
Sample Name
Base Metal
(HBN)
Average
(HBN)
HAZ
(HBN)
Average
(HBN)
Weld Metal
(HBN)
Average
(HBN)
S1
114.97
115.76
137.81
139.34
152.22
155.16122.57 140.00 153.26
109.73 140.22 160.00
M1
113.18
107.66
137.81
137.89
153.26
159.09101.75 142.69 165.00
108.06 133.18 159.00
F1
114.97
111.59
147.33
138.66
169.00
163.33104.83 135.47 165.00
114.97 133.18 156.00

29. 80
90
100
110
120
130
140
150
160
170
180
Microhardness(Brinell)
Weld metal region
Micro-Hardness variation across the Samples
Solid Metal Flux
Fig. 12. Micro-Hardness variation across the Samples

30. • From the Micro-Hardness test results and data, we can observe that the Flux-cored
Welding Process produces the highest value of hardness in the weld metal region as
compared to the rest of the two processes.
• The values are almost the same in the HAZ region for all the three processes. The
values justify the theoretical knowledge of the subject that the hardness of the flux
cored or metal cored electrodes is higher than that of the solid metal wire.
• In theory, metal cored wires show a higher hardness as compared to the flux cored
wires, but the comparison may vary depending on the material and composition of
the metal or flux cored wire used.

31. CONCLUSIONS
 The FCAW process has the lowest weld reinforcement (0.30 mm) as well as depth of penetration
(0.070 mm).
 Despite the low weld reinforcement and depth of penetration, FCAW still shows the highest Micro-
Hardness in the weld region (163.33), followed by MCAW (159.09) and GMAW (155.16).
 The peak temperature of the bead is maximum for FCAW Process (342 °C), then MCAW (322 °C) &
then GMAW (318 °C)
 Thus, FCAW process is the one that reaches the maximum peak temperature using the least
Power/Heat input and also the least weld reinforcement and depth of penetration. Apart from all this,
it produces the strongest weld amongst the three processes.

32. CONCLUSIONS (contd.)
Power Consumption / Heat Input – Maximum in case of Metal Cored Wires (420.3 KJ) than the Solid
Wire (443.3 KJ)& the least in Flux Cored Wires (406.7 KJ).
 The Micro-structure images show clearly that the weld zone in FCAW and MCAW contains granules of
metallic materials deposited onto them from the electrode wires.
 After performing FCAW, we have observed various ‘Chicken Marks’ on the Sample, which are due to
Hydrogen Content in the electrode. These are undesirable, as they can cause problem later. This Problem
has not been occurred in other two processes.

33. References
• Howard B. Cary, 4th Edition1997, Modern Welding Technology, Prentice Hall.
• D.B.Holliday, Gas Metal Arc Welding, Westinghouse Electric Corporation.
• David Widgery, Tubular Wire Welding, Jaico Publishing House.
• ASM Handbook Volume 6: Welding, Brazing and Soldering (1993), ASM
International.
• Modern Arc Welding Technologies, Ador Welding Limited, Second edition, 2005.
• V. Vasantha Kumar and N. Murugan; Effect of FCAW Process Parameters on Weld
Bead Geometry in Stainless Steel Cladding; Journal of Minerals & Materials
Characterization & Engineering, Vol. 10, No.9, pp.827-842, 2011

34. • [Online]http://www.weldguru.com/support-files/flux-cored-arc-welding.pdf
• [Online] http://www.thefabricator.com/article/consumables/an-introduction-to-
metal-cored-wire
• [Online] http://www.esabna.com/us/en/education/blog/advantages-and-
disadvantages-of-metal-cored-wires.cfm
• [Online]http://www.lincolnelectric.com/assets/global/Products/Consumable_MIGG
MAWWires-SuperArc-SuperArcL-56/c4200.pdf