IA-B118-???
EFFECT OF PROCESS PARAMETERS ON FERRITE CONTENT OF
ER308LSI BY MIG WELDING
MUHAMAD IZZUL FAIZ BIN ABD RAHMAN
50215219160
Report Submitted to Fulfill the Partial Requirements
For the Bachelor of Engineering Technology (HONS) in Welding and
Quality Inspection
University Kuala Lumpur
July 2021
DECLARATION
I declare that this report is my original work and all references have been cited
adequately as required by the University.
Date: 23/11/2021
Signature: ……………………………………
(Proposal submission date)
Full Name: Muhamad Izzul Faiz Bin Abd Rahman
ID Number: 50215219160
ii
APPROVAL PAGE
We have supervised and examined this report and verify that it meets the program
and University’s requirements for the Bachelor’s in engineering technology
(HONS) in Welding and Quality Inspection.
Date: 23/1/2021
Signature: ……………………………………
(Proposal submission date)
Supervisor: HJ. Nasrizal Bin Mohd Rashdi
Official Stamp:
Date: 23/11/2021
Signature: ……………………………………
(Proposal submission date)
Supervisor:
Official Stamp:
(Optional)
iii
ABSTRACT
This study shows how process parameters affect ferrite number while joining
ER308LSI diameter of 1.0mm with an inert metal gas (MIG) welding technique.
The type of variable of process parameters is welding current with 70-110 A.
Fisher's ferrite scope was used to determine the most optimistic ferrite
percentage. There will be a total of 5 specimens with the same diameter which is
100mm x 100mm and thickness of 9mm will be tested in this research. Graphically
depicted are the direct and interaction effects of input process parameters.
iv
CONTENTS
DECLARATION
ii
APPROVAL
iii
ABSTRACT
iv
LIST OF TABLES
vii
LIST OF FIGURES
viii
LIST OF ABBREVIATIONS
ix
CHAPTER 1: INTRODUCTION
1.1 Overview
1
1.2 Problem statement
2
1.3 Objectives
3
1.4 Expected Outcomes
3
1.5 Scope and limitation of the research
4
1.6 Significant of research
4
1.7 Gantt Chart
5
CHAPTER 2: LITERATURE REVIEW
2.1 Introduction
6
2.2 Austenitic Stainless Steel
6
2.3 Process Parameter
7
2.4 Weld Overlay
9
2.5 Ferrite Content
10
2.6 GMAW Process
11
2.7 Argon Gas
14
2.8 Fischer Ferrite Scope
15
v
CHAPTER 3: METHODOLOGY
3.1 Introduction
16
3.2 Organization Chart
17
3.3 Research Flow Chart
18
3.3.1 Work Breakdown Structure
18
3.4.1 Research Flow Chart
19
3.4.1 Flow Chart
20
3.4 Literature Review
22
3.5 Sample Preparation
22
3.5.1 Selected Material
22
3.5.2 Plate Dimension
23
3.5.3 Edge Preparation
24
3.5.4 Filler Material Used
24
3.6 Welding Procedure
25
3.6.1 Process Parameter
25
3.6.2 Preliminary Welding Procedure Specification
26
3.6.3 Welding Process
27
3.7 Specimen Preparation
27
3.8 Ferrite Measurement
28
CHAPTER 4: RESULT AND DISCUSSION
4.1 Introduction
29
4.2 Visual Inspection
29
4.3 Time Taken
32
4.4 Ferrite Test
33
4.4.1 Base Metal
34
4.4.2 Heat-Affected Zone (HAZ)
35
4.4.3 Weld Metal
36
4.5 Analysis
37
4.6 Heat Input
37
vi
CHAPTER 5: CONCLUSION
5.1 Introduction
40
5.2 Summary
40
5.3 Future Recommendation
40
REFERENCES
41
APPENDICES
43
vii
LIST OF TABLES
Table No
Title
Page
Table 3.1
Process Parameters
26
Table 3.2
Summary of pWPS
26
Table 4.1
The Time Taken for Each Pass to Complete
32
Table 4.2
Ferrite Percentage Test for Base Metal
34
Table 4.3
Ferrite Percentage Test for HAZ
35
Table 4.4
Ferrite Percentage Test for Weld Metal
36
viii
LIST OF FIGURES
Figure No
Title
Page
Figure 1.1
Gantt Chart
5
Figure 2.1
GMAW Weld Process
12
Figure 3.1
Organization Chart
17
Figure 3.2
Work Breakdown Structure
18
Figure 3.3
Research Flow Chart
19
Figure 3.4
FYP 1 Flow Chart
20
Figure 3.5
Activity Flow Chart
21
Figure 3.6
Main Chemical Composition of Base Metal
23
Figure 3.7
Dimension of the Base Metal
23
Figure 3.8
Grinding Machine
24
Figure 3.9
Filler Material
24
Figure 3.10
Welding Sequence
25
Figure 3.11
Universal Polishing Machine and Carbide Sandpaper
27
Figure 3.12
The Schematic Configuration of The Ferrite Scope
28
Figure 3.13
The Value Measured Along the Axis of The Deposition
28
Figure 4.1
Surfacing Weld 70A
29
Figure 4.2
Surfacing Weld 80A
30
Figure 4.3
Surfacing Weld 90A
30
Figure 4.4
Surfacing Weld 100A
31
Figure 4.5
Surfacing Weld 110A
31
Figure 4.6
FERRITESCOPE FMP30
33
Figure 4.7
Grinded Weld Metal
34
Figure 4.8
Average Result of Ferrite Test on Base Metal
35
Figure 4.9
Average Result of Ferrite Test on HAZ
36
Figure 4.10
Average Result of Ferrite Test on Weld Metal
37
Figure 4.11
Comparison in Heat Input of all Specimen
39
ix
LIST OF ABBREVIATIONS
GMAW
Gas Metal Arc Weld
FN
Ferrite Number
ASTM
American Society of Testing Material
HAZ
Heat Affected Zone
MIG
Metal Inert Gas
WBS
Work Breakdown Structure
FCC
Face-Center Cubic
ASME
American Society of Mechanical Engineering
AWS
American Welding Society
WPS
Welding Procedure Specification
pWPS
Preliminary Welding Procedure Specification
x
CHAPTER 1: INTRODUCTION
1.1
Overview Research
STAINLESS STEELS are iron-base alloys with a minimum of roughly 12% Cr,
which is required to avoid rust formation in unpolluted environments (hence the
designation stainless). Only a few stainless steels have more than 30% Cr and
less than 50% iron. The creation of an invisible and adhering chromium-rich oxide
coating gives them their stainless properties. In the presence of oxygen, this oxide
develops and heals. Nickel, manganese, molybdenum, copper, titanium, silicon,
niobium, aluminium, sulphur, and selenium are some of the other elements that
have been added to improve specific properties. Carbon is normally present in
amounts ranging from less than 0.03% to over 1.0% in certain grades.
There was a lot of a new type of stainless steel that have been introduced
and commercialized since the first discoveries of these alloys. Stainless steel is a
product that have been recognised for their corrosion-resistance properties and
they also have a good versality in processing and application, due to their strict
composition of control and ferrite/ austenite balance. However, this balance may
be disrupted during welding in both the weld metal and the Heat Affected Zone
(HAZ) due to rapid cooling rates.
1
1.2
Problem Statement
Because of their superior corrosion and oxidant resistance, stainless steels are
widely employed in a range of product forms for architectural, consumer, and
industrial applications. However, they are prone to corrosion during welding.
Corrosion is a condition that causes the steel structure to deteriorate and
eventually fail. It cannot be completely removed, but it can be decreased to some
extent. Surfacing creates a corrosion-resistant protective coating on top of the
underlying metal.
While surfacing process can create a corrosion-resistant protective layer,
another problem that may arise in surfacing process is that the appearance of
delta ferrite in microstructure of stainless-steel during welding. Delta ferrite phase
can cause a discrete reduction on corrosion resistance, fatigue crack, and pitting
corrosion.
Heat, pressure, and caustic conditions necessitate metallurgical integrity in
materials and welds. In stainless steel welds, pipes, plates, pressure vessels, and
petrochemical components, proper ferrite measurement can assist prevent both
solidification cracking and corrosion. Stainless steel can lose ductility, hardness,
and corrosion resistance if the ferrite content is too high, especially at high
temperatures. Stainless steel welds are subject to hot cracking or solidification
cracks if the ferrite percentage is too low.
.
2
1.3
Objectives
The main purpose of this investigation is to find out the effect of process
parameter on ferrite number in surfacing weld of ER308LSi stainless steel by MIG
welding.
Thus, to achieve the above purpose, there are two (2) objectives that have
been identified as follows:
1. To analyze the data of ferrite number on the base metal using fisher’s ferrite
scope after weld process
2. To compare which weld current will effectively controlling the ferrite number on
surface metal.
1.4
Expected Outcomes
The expected outcome of this research as follows:
1.
The intended outcome of this study is that the process parameter will affect
the dilution of bead weld process, hence changing the ferrite content on weld
surface. For instance, increasing in welding current may resulted in increased of
deposition of filler material.
2.
Furthermore, the increase in welding current will resulted in decrease in
ferrite number to mid value of welding current level thereafter a sudden increase
in ferrite number. This phenomenon may happen because as the current level
rises, the heat input to the base metal rises, increasing the ferrite number.
3.
The variable in contact tip to work distance is predicted to not having any
significance changes in ferrite number.
1.5
Scope and Limitation of the project / research
The scope of this research is to determine the ferrite content of welded
surfaces that can be done on the surface of steel plate ASTM 36 after ER308LSi
3
filler material been used by using the GMAW process. The changing of process
parameter such as welding speed, welding current and contact tip to work
distance will affect the ferrite number on the welded metal. The morphology
analysis will determine the formation and changes in the microstructures. Ferrite
number examination will be performed by using Fischer Ferrite Scop.
However, the limitation for this research study is only limit to the type of the ASTM
36 that used as the base metal. In addition, the torch angle will fix permanently as
90 degrees. There are many considerations especially on the essential variable,
supplementary variable, and non-essential variable in the welding process. So,
the data that will obtained are restricted and following the associated variables in
this research
1.6
Significant of Project/ Research
The goal of this research is to help welding specialists on the need of having
complete control over process parameters for weld to achieve high corrosive
resistance, high quality, and low dilution percentage. Data on the potential
impacts of ferrite content on the stainless steel of weld overlay is also considered.
Furthermore, this study is crucial because it will assist industry in
understanding the probable consequences of varying the value of a process
parameter in the welding process on the ferrite percentage. On the other hand,
the study will motivate other researchers and engineers to investigate the various
types of austenitic stainless steel that can be used as filler material in the welding
process. Furthermore, the research goal is to seek continual improvement to
obtain correct data on the process parameter affecting process parameter to
assure welding quality and cost effectiveness during the fabrication process.
4
1.7
Gantt Chart
The planning of this research is shown in Figure 1 below.
Figure 1.1: Gantt Chart
5
CHAPTER 2: LITERATURE REVIEW
2.1
Introduction
This chapter discussed the related information concerning the research topic such
as effect of process parameter etc. In addition, this chapter also discussed about
the previous work done by the other researchers concerning the research topic
and title.
2.2
Austenitic Stainless Steel
Austenitic stainless steel is the most prevalent and best-known type of
stainless steel. They may be recognised most easily by the fact that they are not
magnetic. They are extremely malleable and can be welded; they can be used
successfully at temperatures ranging from those found in cryogenic environments
to those found in furnaces and jet engines. Their exceptional resistance to
corrosion is due, in part, to the presence of between 16 and 25 per cent chromium
as well as the possibility of dissolved nitrogen in the material. Because of the high
cost of the nickel that is necessary to keep the austenitic structure of these alloys
intact, their usage is not nearly as widespread as it could be.
When it comes to the field of metallurgy, austenitic stainless steels provide
a diverse variety of advantages. They can be worked so that they are soft enough
(i.e., with a yield strength of roughly 200 MPa) to be formed easily using the same
tools that are used for carbon steel, but they can also be worked so that they are
very strong (with yield strengths that reach 2,000 MPa) when they are worked so
hard (290 ksi). Their austenitic (fcc, face-centred cubic) structure is ductile and
resistant to temperatures below zero. At higher temperatures, they do not have
the same rate of deterioration as ferritic (bcc, body-centred cubic) iron-base
alloys. The most corrosion-resistant grades can withstand the corrosive
6
conditions of the boiling ocean, while the least corrosion-resistant grades may
withstand the corrosive conditions of the familiar environment.
The austenitic grades of stainless steel are the classes that are used the
most frequently. This is due to the austenitic grades' excellent predictability of
corrosion resistance mixed with their great mechanical properties in a variety of
contexts. If they are used effectively, the design engineer may be able to realise
significant cost reductions, therefore. They are a metal alloy that is simple to work
with and has a lower cost across its whole life cycle than many other materials.
[1].
2.3
Process Parameter
The Gas Metal Arc Welding (GMAW) technique is well-known because it allows
for variable input parameters that we may adjust. In GMAW, the parameters often
include

welding speed,

current, voltage,

the diameter of the wire.

The shielding gas flow rate and the

the distance from the contact tip to the job.
Even though the experiment that will be carried out will use gas metal arc welding,
the process parameters will still have to be controlled manually. Because it is
responsible for determining the mechanical quality of the weld, the welding
parameter procedure is exceptionally significant. Therefore, the parameters of the
process that will be controlled manually will be the welding speed, the welding
current, and the distance from the contact tip to work. To produce welds of a
higher quality and achieve the required bead geometry dimensions, it is
necessary to maintain total control over the essential process parameters.
[2].
7
Welding Speed
Arthur Casarini et al [3] investigated the influence and optimization of the
GMAW parameter on mechanical properties and weld geometrical. They stated
that the welding speed has appeared as the most influential role in determine the
weld geometry, contributing up to 63% to reinforcement, 66% to the width and
66.9% to penetration. The effect of weld speed was discovered to be that the
joints welded at a high welding speed had a smaller weld bead size, greater
tensile strength and elongation, a higher hardness, and a more significant
propensity for pitting corrosion. This was compared to the joints welded with a
medium and low welding speed. When the welding speed was increased, the
dendrite length and inter-dendritic spacing in the weld zone decreased. This was
the primary explanation for the visible changes in the weld joints' tensile,
hardness, and corrosion characteristics [4].
Welding Current
Izzatul Aini Ibrahim et al [5] conducted an experiment on the effect of
GMAW process on different welding parameter. They predicted that the
increasing number of values in welding current can lead to the greater value of
depth penetration. Junling Hu et al [6] have conducted an experiment on effects
of welding current on metal transfer and weld pool dynamics in gas metal arc
welding. They concluded that when using a constant welding current, it was
discovered that increasing the current led to deeper penetration and a larger weld
pool. On the other hand, when using a pulsed welding current, it was found that
the shape of the weld pool and the depth of the penetration could be controlled
by adjusting the droplet size, frequency, and velocity through the pulse shape.
8
Contact Tip to Work Distance
Amos Robert et al [7] investigated the behaviour of process parameter
during stainless steel cladding. They concluded that stand of the distance is the
dominant parameter to decide the bead appearance than with diffusion
temperature and welding speed. The AWS A3.0 Standard does not define this
phrase (contact tip to work distance), even though it is widely used in the industry
and contact tip to work distance is even included in several the processes for
welding. When preparing the weld or programming the robot, the optimum
moment to measure the contact-tip-to-work distance is when you hit the arc, since
you can take a physical measurement before you hit the arc, which is the most
significant time. After the arc has been struck, the length of the arc will be
determined by the voltage, and the extension of the electrodes can be measured
either by sight or by the resistance in the circuit. When individuals talk about the
distance from the contact tip to work, they frequently imply the total of the arc
length and the electrode extension [8].
2.4
Weld Overlay
Corrosion-resistant weld overlays are frequently utilized to extend the
service life of components constructed from corrosive materials. A fundamental
challenge with an arc-weld-based overlay is dilution, or the degree to which the
addition of base metal alters the chemistry of the deposited metal. While some
general information is available on the level of dilution connected with common
arc welding techniques, the exact dilution associated with a specific method might
vary widely depending on the welding parameters used. As unbalanced chemistry
can lower the service life of a coating usually, it is vital to maintain tight control
over the dilution. Several variables impact dilution, such as the welding current,
the arc voltage, the current polarity, the electrode diameter, the electrode
extension, the weld-bead separation, the welding speed, the electrode grinding
angle, the welding position, the shielding gas composition, and so on. To achieve
the required qualities on the overlay, it is important to manage these factors within
predetermined boundaries, which necessitates a thorough grasp of how each
variable affects dilution. Codes and standards such as ASME Section IX for the
9
qualifying of welding methods say that heat input for the first weld layer is a crucial
variable, i.e., a change in heat input of more than 110% of the certified value
necessitates requalification. The same heat output may be attained by adjusting
the welding current and speed. For several operations, it will have a completely
distinct impact on the penetration depth and, consequently, the dilution. In many
circumstances, the overlap between neighboring weld beads is more important
than the heat input in determining the dilution [9].
2.5
Ferrite Content
The amount of ferrite in a steel is measured by its ferrite content. Ferrite is one
type of microstructure (internal crystal structure) that can exist in steel. The crystal
structure of an alloy contributes to its physical and mechanical properties.
In stainless steel, a ferritic microstructure is typically associated with high
strength and resistance to chloride stress corrosion cracking. It is also magnetic,
which can be used to measure the ferrite content of duplex and super duplex
stainless steels with a ‘Ferritescope.’ This is a useful technique because it can be
used ‘in-situ’ to assess weld quality or review incoming stock without requiring test
samples to be cut from the components [9].
Stainless steels in the 300 series, such as 304L and 316L, have an austenitic
microstructure and are non-magnetic. They are essentially free of ferrite, which is
magnetic, in the annealed state. The presence of ferrite in these alloys’ cast
products is common. When these alloys are cold worked or work hardened, some
ferrite is formed. The products will have a magnetic propensity in both
circumstances. In some situations, ferrite can reduce corrosion resistance. There
are also instances where magnetic properties interfere with the end product’s
performance.
The alloy composition can be used to adjust the ferrite content of the cast alloy.
Carbon, Nitrogen, Nickel, and Manganese are all strong austenite formers, hence
adding more of them to an alloy will lessen the potential for ferrite formation. There
are various ways for determining ferrite content, but the DeLong diagram is one
of the most frequent. Ferrite inhibits the formation of solidification cracks in steel
during cooling. It’s not uncommon for 304 castings (CF8) to contain ferrite in the
10
range of 8% to 20%. The wrought 304 stainless cast ingot composition is also
balanced to have 1% to 6% ferrite, which decreases the risk of cracking during
forging or hot working [10]
According to Rho et al [11] The effects of delta ferrite content on 304L stainless
steel during a continuous low-cycle fatigue test at various temperatures were
investigated. They found out that the fatigue crack was caused by surface delta
ferrite. Lia et al [12] studied development and microstructural evolution of the delta
ferrite phase in SAVE12 steel. They also showed that the high content of ferrite
forming alloy elements caused the formation of delta ferrite.
The chemical composition of the filler material during cladding determines the
base material’s corrosion resistance. The higher the ferrite number, the worse the
material attribute. As a result, obtaining the optimal amount of ferrite numbers
during cladding is critical [13]. During cladding, the microstructure of austenitic
stainless steel reveals a delta ferrite phase, which has a decremented influence
on corrosion resistance [14].
2.6
GMAW Process
GMAW is a welding method that joins metals by heating them to their melting
point using an electric arc. The arc is struck between a continuous, consumable
bare (not coated) electrode wire and the workpiece, and it is insulated from
ambient pollutants by a shielding gas. Shielding is achieved by inundating the arc,
the melted end of the metal electrode, and the weld pool region with shielding
gas. The bare wire is fed constantly and automatically from a spool via the welding
gun, as shown in below schematic illustration of the GMAW process.
11
Figure 2.1: GMAW Weld Process [15]
The fundamental concept of GMAW was introduced in the 1920s; however,
the process was not commercially viable until 1948, when it was implemented as
a high-current-density, small-diameter, 'bare-metal-electrode' method employing
an inert gas for arc-shielding. Consequently, the procedure became known as
metal inert gas welding. The GMAW was first mainly used for aluminium welding.
However, the following process innovations included operation at low current
densities and pulsed current, applicability to a wider variety of materials, and the
use of reactive gases (mainly CO2) and various combinations of gas mixes.
Both inert and reactive gases are used in this procedure as shielding gases.
The numerous metals on which GMAW is used and the modifications to the
process have resulted in various GMAW names. When this same welding
procedure was used on steel, it was discovered that inert gases (argon and
helium) were costly; thus, a reactive gas, CO2, was employed as a substitute;
hence the phrase "CO2 welding." Refinements in GMAW for steel welding have
resulted in the utilisation of gas mixtures, such as CO and argon and even oxygen
12
and argon. Occasionally, argon is combined with small amounts of oxygen (up to
5 percent). Properly blended compositions improve arc performance with less
spatter and improve the weld's wetting (i.e., spreading and adhering) to the base
metal. Some mixes are commercially available in cylinders and have been
standardized. The selection of gases (and gas mixes) depends on the metal being
welded and other variables. Inert gases are utilised to weld aluminium alloys and
stainless steel, whereas CO2 or an argon/carbon dioxide combination is typically
employed to weld low and medium carbon steel. Combining a bare electrode wire
and shielding gases removes the slag coating on the weld bead, eliminating the
requirement for manual grinding and cleaning of the deposited slag in the weld
zone. Consequently, the GMAW method is perfect for doing numerous welds
passes on the same joint, and a significantly greater production rate is attainable.
In manufacturing, agriculture, the construction sector, shipbuilding, the marine
and ground vehicle industries, and mining, GMAW is used for various
applications. The method is used to produce welded pipes, pressure vessels,
structural steel components, furniture, and auto parts, amongst other things. All
economically essential metals, such as carbon steel, high-strength low-alloy steel,
stainless steel, aluminium, copper, titanium, and nickel alloys, may be welded
using the GMAW process. This process can be achieved by combining shielding
gas, electrodes, and welding variables.
GMAW may be accomplished in three distinct methods:
1. Semiautomatic welding — only the electrode wire feeding is controlled by
equipment. The motion of the welding gun is manually controlled. This is
referred to as "handheld welding"
2. Machine welding uses a gun coupled to a manipulator (not handheld). An
operator must establish and modify the controls that continuously move the
manipulator
3. Automatic welding employs welding equipment without the need for the
welder or operator to modify the parameters constantly. Mechanical
sensing devices on specific equipment control the correct gun alignment in
a weld joint [15].
13
2.7
Argon Gas
Argon that has been combined with CO2 or O2 is recommended. For the welding
of mild and low-alloyed steels, argon mixtures with 5–20 percent carbon dioxide
are frequent. It is asserted that raising the CO2 concentration in the shielding gas
decreases the inclusion and porosity content of the weld [16].
Argon mixtures with a lower oxidizing gas percentage will often yield more
excellent weld characteristics than CO2 shielding alone. The oxygen
concentration is appropriate since too little oxygen might potentially be damaging
to toughness [17]. For welding stainless steel, argon with low quantities of an
oxidant (either oxygen or carbon dioxide) is a popular gas mixture. The loss of
manganese, chromium, and niobium increases as the concentration of an
oxidising element in the shielding gas rises. The addition of CO2 to the mixture
decreases the cost and increases the wettability of the weld bead, consequently
enhancing the quality of the weld. However, the presence of CO2 causes the
deposited metal to absorb carbon and oxidise. The addition of carbon to the weld
pool can lower the ferrite concentration of the bead. Because carbon is a powerful
austenite producer at high temperatures and during cooling, martensite can
develop at the ferritic grain boundaries, reducing the joint's tensile strength.
Adding a little quantity of oxygen can improve dip transfer when additional
oxidation can be tolerated. The addition of hydrogen to argon increases the
volume of the molten material and enables faster welding. Nevertheless, it can
cause hydrogen fractures in welds, and its use is restricted. In some welding
procedures, helium can be added to the gas mixture to improve weld penetration
and puddle fluidity. The use of helium increases travels speeds while decreasing
distortion [18-23].
14
2.8
Fischer Ferrite Scope
The magnetic induction method is used by the FERITSCOPE to determine the
ferrite content in austenitic and duplex steel. All magnetizable structural sections
are measured, including strain-induced martensite and various ferritic phases, in
addition to delta ferrite.
It can be used to take measurements in accordance with the Basler Standard
and DIN EN ISO 17655. Site measurements, such as austenitic plating and weld
seams in stainless steel pipes, containers, boilers, and other austenitic or duplex
steel goods, are examples of applications [24]
15
CHAPTER 3: METHODOLOGY
3.1
Introduction
This chapter explains and clarifies the research methods used in this study. To
ensure that the research study runs smoothly, the working flow, which includes
the Work Breakdown Structure (WBS), general research flowchart, and
experimental flowchart, will be defined to avoid any unfavourable outcomes during
the research process.
In this chapter, all research procedures will be explained, including the
process prior to sample preparation, sample preparation, welding process,
experimental specimen sectioning process, and the procedure for each testing
and examination that will be conducted during Final Year Project 2. The complete
method of the intended research study was outlined in this chapter, which was
separated into seven parts. The focus of the research study is Section 3.5, which
details the sample preparation technique. Following that, Section 3.6 will detail
the welding method, while Section 3.7 will cover the specimen preparation and
experimental procedure that will be used in this study.
16
3.2
Organization Chart
Organization chart will help us in making clear of the hierarchical status position
on this research study. It is crucial in ensuring the effectiveness for the flow of the
project. Below is the organization chart for this research study.
HJ. NASRIZAL BIN MOHD RASHDI
SUPERVISOR
MUHAMAD IZZUL FAIZ BIN ABD
RAHMAN
STUDENT
Figure 3.1: Organization Chart
17
3.3
Research Flow Chart
3.3.1 Work Breakdown Structure
The Work Breakdown Structure is a breakdown of the complete activities
that will be addressed in this study based on the scope of work. The scope
of work is divided into four sections: research field selection, proposal
writing, scheduling, and experimental procedure planning. The WBS
serves as a roadmap for the research team to stay on track and complete
the project on time. The planning, on the other hand, is dependent on any
constraints that arise as the research progresses.
Phase 1:
INITIATION
Phase 2:
PLANNING
Phase 3:
SAMPLE
PREPARATION
Phase 4:
LABORATORY
PROCESS
Figure 3.2: Work Breakdown Structure
18
Phase 5:
CLOSURE
3.3.2 Research Flow Chart
There are several phases of activity that should be taken into consideration
in this research, as presented in flow chart at Figure
Figure 3.3: Research Flow Chart
19
3.3.3 Flow Chart
I. FYP1 Flow Chart
Figure 3.4: FYP1 Flow Chart
20
II. Activity Flow Chart
Figure 3.5: Activity Flow Chart
21
3.4
Literature Review
The purpose of literature review is to describe the effect of changing the variable
in process parameter in welding process and the effect of it onto the ferrite
number. Gas Metal Arc Welding (GMAW) is used and the specimen that be
welded is 9 mm thick. In this experimental procedure, different process parameter
such as weld speed, weld current, and contact tip to work distance will be test
upon A36 Carbon Steel by using ER308LSi as filler material.
3.5
Sample Preparation
To produce a single bead of weld process, it is important to take into an account
the method of the plate preparation, edge preparation, welding procedure
specification (WPS), welding method and the specimen dimension to make sure
that the welded sample are suited for ferrite testing.
3.5.1 Selected Material
A36 is carbon steel that contains a small amount of sulphur. Carbon steels
with less than 0.3 per cent carbon by weight are categorised as low carbon
steels. As a result, this makes A36 steel remarkably versatile as generalpurpose steel since it is readily machined, welded, and shaped.
Additionally, the low carbon content of A36 steel makes heat treatment
ineffective. Other alloying elements such as manganese, sulphur,
phosphorus, and silicon are frequently present in trace levels in A36 steel.
These alloying elements provide the appropriate chemical and mechanical
qualities to A36 steel. However, due to the lack of nickel or chromium in
A36, it lacks superior corrosion resistance [18].
Below shows the main chemical composition of base metal A36 Carbon
Steel.
22
Figure 3.6: Main Chemical Composition of Base Metal [18]
3.5.2 Plate Preparation
The dimension of the plate that will be using is proximately 100 mm x 100
mm with 9 mm thickness from structural plate A36 Carbon Steel. There will
be a total of 5 specimen will be prepared with different process parameters.
To remove dirt and rust from the top surface of the base material, a steel
wire brush and emery sheets were used to clean it. The figure below shows
the dimension of the plate structural A36 Carbon Steel.
9mm
Figure 3.7: Dimension of The Base Metal
23
3.5.3 Edge Preparation
Each plate's edge preparation is done with a grinding machine as shown
in the fig below.
Figure 3.8: Grinding Machine
3.5.4 Filler Material Used
The GMAW welding method has been chosen for this investigation. As a
result, the filler metal that will be utilised is ER308LSi solid wire with a
diameter of 1.0 mm. Figure below shows ER308LSi stainless steel filler
wire that will be used in the process.
Figure 3.9: Filler Material
24
3.6
Welding Procedure
Welding operations is a crucial stage in a variety of fabrication processes. Before
any welding operation can begin, a detailed method must be recorded. Procedure
preparation is important since the procedure involves the manufacturer, authority
staff, and the inspecting body using certain codes and standards, project
specifications and requirements, and standard of engineering practises. The
specimen's base material and filler material are shown in the figure below.
A36
Figure 3.10: Welding Sequence [25]
3.6.1 Process Parameter
The GMAW process design is recognised to have many input parameters
to control. Voltage, current, speed, wire diameter, shielding gas flow rate,
electrode orientation, and distance between nozzle and plate are all factors
to consider. These variables can have a direct impact on the geometry of
the weld bead, angular distortion, temperature field, and residual stresses.
Current, speed, and contact tip to work distance were chosen as study
input characteristics in this research. Table below shows the value process
parameter that will be used.
25
Table 3.1: Process Parameters
Specimen No.
Current
1
70A
2
80A
3
90A
4
100A
5
110A
For this research, a lot of process parameter will be fixed to keep the
research fair such as torch angle (90 degree) and contact tip to work
distance.
3.6.2 Preliminary Welding Procedure Specification
Before welding the plate, the Pre-Welding Procedure Specification (WPS)
must be set up. A document defining welding techniques is known as a
pre-Welding Procedure Specification (pWPS). It is an important welding
technician guideline for making high-quality weld overlay. It essentially
gives thorough information welding parameters and the value that have
been choose. Table below shows the summary of Preliminary Welding
Procedure Specification (pWPS).
Table 3.2: Summary Of pWPS
Preliminary Welding Procedure Specification Summary
Welding Process
Gas Metal Arc Welding
Welding Position
1G
Filler Material
ER308LSi
Base Material
A36 Carbon Steel
Welding
Current
70-110
Parameter
26
3.6.3 Welding Process
Gas Metal Arc Welding (GMAW) process used to produce weld on plate
mild steel. Metal inert gas welding is widely used for welding austenitic
stainless steel because of several advantages, including the ease with
which process parameters can be controlled, the ability to produce good
bead dimensions, the reduction of dilution percentages, the reduction of
spatter and fumes, and the high metal deposition rate. As a shielding gas,
a mixture of Argon and Carbon dioxide (98 percent and 2%, respectively)
is provided at a flow rate of 20 lit/min during the trials.
3.7
Specimen Preparation
To produce the test specimen, the top surface of the specimens is grounded as a
flat surface without disrupting the bead geometry or surface texture.
After metallographic grinding and polishing procedures, etching is applied on the
surface of the test specimen. Etching is a chemical or electrolytic process. Etching
improves the contrast on surfaces so that the microstructure or macrostructure
may be seen. Following metallurgical operation, it was polished with etching
solution and polished to a mirror finish. The test specimens should be flat,
polished, and defect-free for maximum precision. As indicated in the figure below,
a consistent surface can be achieved by utilising a polishing equipment and
abrasive carbide sandpaper with a scale of 240-2200 grit.
Figure 3.11: Universal Polishing Machine and Carbide Sandpaper
27
3.8
Ferrite Measurement
The ferrite number on welded specimens was measured using a Fischer
FERRITESCOPE MP30. The measurement spans from 0.1 to 110 ferrite number
or 0.1 to 80 percent ferrite in austenitic stainless steel. Figure below shows depicts
a schematic configuration of the ferrite scope and specimen.
Figure 3.12: The Schematic Configuration of The Ferrite Scope [25]
Before measuring the ferrite number, the instrument must be calibrated
according to an ANSI/AWS A4.2M/A4.2: 1997 standard specimen using an
existing prepared specimen and ferrite form. The values are measured on the
prepared surfaces of the 5 specimens, and five values are measured along the
axis of the deposition in each specimen as shown in the figure below.
Figure 3.13: The Value Measured Along the Axis of The Deposition [25]
28
CHAPTER 4: RESULT AND DISCUSSION
4.1
Introduction
The results of the testing that has been carried out are going to be
discussed in this chapter. In this section, we also go through how to understand
the data and analyze it. There will be a presentation of the study's findings and an
in-depth analysis of those findings to provide more comprehensive knowledge
and comprehension of the purpose of the study.
4.2
Visual Inspection
This section discusses the first goal of the investigation, which is to
compare both specimens by visually examining them and draw comparisons
between them. After the GMAW welding technique has been completed, a visual
examination is carried out and graded on its results.
Figure 4.1: Surfacing Weld 70A
29
Figure 4.2: Surfacing Weld 80A
Figure 4.3: Surfacing Weld 90A
30
Figure 4.4: Surfacing Weld 100A
Figure 4.5: Surfacing Weld 110A
31
The results of the visual inspections have been carried out. According to Figure
4.1, there are some visual defects on the surface of weld plate such as spatter.
We also can clearly saw that the weldment is a bit undercut. Though, this defected
can be forgive since this is not a weld joint and merely just surfacing weld. For
figure 4.2, the defect of undercut has slightly increased from the figure 4.1 and
the spatter also have increased. For the rest of the figures, we can see that the
weldment has slightly defect from the first two. The reason for this was because
the skill and technique of the welder. From the visual inspection, we can deduce
that the welder needs several passes to complete until he was comfortable to
complete the other weld passes. From the last three figure, we can observe that
the weld bead become slightly wider than the rest. This happened due to the
increased of the amperage resulted in increased of deposition rate.
4.3
Time Taken
Table 4.1: The Time Taken for Each Pass to Complete
Specimen
Current (A)
Time (s)
1
70
52
2
80
46
3
90
45
4
100
41
5
110
38
32
Based on the table above, we can observe that the time taken to complete
one pass for the 70A took the longest time in to complete the weld in the research,
with a total of 52 second. The time taken to complete the welding for the 110A
has the shortest time, with a total of 38 second. From the data above, we can see
that the time taken for specimen 2 does not far off from the specimen 3 with a
total of 46 and 45 second respectively. We also can see that from 70A to 110A,
the time taken for the pass to complete has reduced significantly.
4.4
Ferrite Test
This section discussed about the results that obtained after using
FERITSCOPE FMP30 (Fig.4.6). The result of the ferrite test will be compared
between the different current setting. Before ferrite testing, the surface of the
weldment will be grinded into smooth surface (Fig.4.7) so that it will not disrupt
the reading of the ferrite test. The ferrite scope will be calibrated according to the
standard of AWS A4.2. There will be three total main places to test which is the
weldment, heat-affected-zone (HAZ), and the base metal. Below is the result of
ferrite percentage after the testing has done.
Figure 4.6: FERRITESCOPE FMP30
33
Figure 4.7: Grinded Weld Metal
4.4.1 Base Metal
Table 4.2: Ferrite Percentage Test for Base Metal
Base Metal
Ferrite Percentage Test (%)
Specimen
Average
70A
80A
90A
100A
110A
47.8
53.2
53.1
77.1
74.5
53.6
64.4
63.5
64.4
55.3
47.2
60.9
52.9
62.6
50.7
63.4
47.5
48.9
64.2
54.4
47.8
48.3
51.6
57
55.2
51.96
54.86
54
65.06
58.02
34
Base Metal
70
60
50
40
30
20
10
0
70A
80A
90A
100A
110A
Base Metal
Figure 4.8: Average Result of Ferrite Test on Base Metal
4.4.2 Heat-Affected Zone (HAZ)
Table 4.3: Ferrite Percentage Test for HAZ
70A
HAZ
Ferrite Percentage Test (%)
Specimen
Average
80A
90A
100A
110A
47.6
70.7
50
86.5
58.2
83.7
65.5
51.6
82.5
66.1
53.5
50.6
73.2
62.3
64.6
56.6
50
54.3
56.6
58.5
68.8
57.7
62.3
51.7
67.8
62.04
58.9
58.28
67.92
63.04
35
HAZ
70
68
66
64
62
60
58
56
54
52
70A
80A
90A
100A
110A
HAZ
Figure 4.9: Average Result of Ferrite Test on HAZ
4.4.3 Weld Metal
S
Table 4.4: Ferrite Percentage Test for Weld Metal
Weld Metal
Ferrite Percentage Test (%)
Specimen
Average
70A
80A
90A
100A
110A
7.1
4.1
4.5
5.1
6.9
10
5.4
7.2
7.0
6.2
9.5
7.2
6.3
6.3
6.2
10.5
7.3
5.9
6.2
6.5
8.6
6.8
6.0
5.0
5.0
9.4
6.16
5.98
5.92
6.16
36
Weld Metal
10
9
8
7
6
5
4
3
2
1
0
70A
80A
90A
100A
110A
Weld Metal
Figure 4.10: Average Result of Ferrite Test on Weld Metal
4.5
Analysis
As shown in Figure 4.10, a rise in the welding current causes a drop in the
ferrite percent, but only up to the point when the current reaches its midpoint;
beyond that, there is a slight increase in the ferrite percent. This is mainly because
at higher current levels, and the base metal is subjected to a more significant
amount of heat, which results in a rise in the ferrite percentage.
From the Figure 4.8, there was a rise in the ferrite percentage in the first
increased of welding current in base metal then a slightly decrease. At the
midpoint, we can see there was a sudden rise in ferrite percent. a rise in the
welding current causes a drop in the ferrite number, but only up to the point when
the current reaches its midpoint; beyond that, there is an abrupt increase in the
ferrite number.
4.6
Heat Input
The idea that underlies the significance of the amount of heat introduced
during welding is that the rate at which the weld cools will slow down
proportionately to the amount of heat raised. The grain size of most materials will
37
grow in the weld and heat-affected zones (HAZ) of the base metal if the cooling
rate is slowed down. Formula for heat input is as follow:
Heat Input = (60 x Amps x Volts) / (1,000 x Travel Speed in in/min) = KJ/in
Travel Speed = Length of Weld / Time to weld
So, for specimen 1:
52 second = 0.867 min
Travel Speed = 100mm / 0.867 min
Travel Speed = 115.34 mm per min
Heat Input = (60 x 70 x 18.4) / (1,000 x 115.34 mm/min) = 0.67 KJ/mm
For specimen 2:
46 second = 0.767 min
Travel Speed = 100mm / 0.767 min
Travel Speed = 130.378 mm per min
Heat Input = (60 x 80 x 19.8) / (1,000 x 130.378 mm/min) = 0.729 KJ/mm
For specimen 3:
45 second = 0.75 min
Travel Speed = 100mm / 0.75 min
Travel Speed = 133.33 mm per min
Heat Input = (60 x 90 x 20.2) / (1,000 x 133.33 mm/min) = 0.82 KJ/mm
38
For specimen 4:
41 second = 0.68 min
Travel Speed = 100mm / 0.68 min
Travel Speed = 147.06 mm per min
Heat Input = (60 x 100 x 20.4) / (1,000 x 147.06 mm/min) = 0.83 KJ/mm
For specimen 5:
38 second = 0.63 min
Travel Speed = 100mm / 0.63 min
Travel Speed = 158.73mm per min
Heat Input = (60 x 110 x 21.9) / (1,000 x 158.73 mm/min) = 0.91 KJ/mm
Heat Input
1
0,9
0,8
0,7
0,6
0,5
0,4
0,3
0,2
0,1
0
Specimen 1
Specimen 2
Specimen 3
Specimen 4
Specimen 5
Heat Input
Figure 4.11: Comparison in Heat Input of all Specimen
39
CHAPTER 5: CONCLUSION
5.1
Introduction
The outcomes of the inspections and tests that have been carried
out are covered in this chapter's discussion. Following the completion of the
collection and organization of the data, the research results will be utilized to
achieve the goals that have been set.
5.2
Summary
The purpose of this research was to do a comparison on ferrite
content between different current range from 70A to 110A using GMAW process
on welded low carbon steel. The surfacing weld are chosen in this research to
make comparison on ferrite content between different welding current. After
collecting and analysing the data from the appearance of the weld, the time take
to finish weld, the ferrite content test, we can conclude that the weld quality for
current 110 is the most optimum and reasonable as the quality of the weld, time
taken to finish the weld and the ferrite content far exceed than others.
5.3
Future Recommendation
For further research, improvement could be done to ensure the result are
more precise and wider range of data can be identified. The recommendation
could be to do research on different material with the same filler material or vice
versa so a wider range of result can be obtained. Lastly, the recommendation that
can be applied is to do a preheat and post heat treatment to control or prevent
any defects and discontinuities.
40
REFERENCES
[1]
Austenitic Stainless Steels - ASM international. (n.d.). Retrieved June 2,
2022,
from
https://www.asminternational.org/documents/10192/3473958/05231G_Sa
mple.pdf/7c5e4830-b443-4c71-a8c8-1a85c5b39dc5
[2]
S. C. Juang and Y. S. Tarng, Process parameter selection for optimizing
the weld pool geometry in the tungsten inert gas welding of stainless steel,
Journal of Material Processing Technology, 122 (2002) 33-37
[3]
Casarini, A., P. Coelho, J., T. Olívio, Émillyn, Braz-César, M., & Ribeiro, J.
(2020). Optimization and Influence of GMAW Parameters for Weld
Geometrical and Mechanical Properties Using the Taguchi Method and
Variance
Analysis. KnE
Engineering, 5(6),
781–794.
https://doi.org/10.18502/keg.v5i6.7097
[4]
Chuaiphan, Wichan; Srijaroenpramong, Loeshpahn (2014). Effect of
welding speed on microstructures, mechanical properties and corrosion
behavior of GTA-welded AISI 201 stainless steel sheets. Journal of
Materials
Processing
Technology,
214(2),
402–408.
doi:10.1016/j.jmatprotec.2013.09.025
[5]
Izzatul Aini Ibrahim, Syarul Asraf Mohamat, Amalina Amir, Abdul Ghalib,
The Effect of Gas Metal Arc Welding (GMAW) Processes on Different
Welding Parameters, Procedia Engineering, Volume 41,2012, Pages
1502-1506,ISSN 1877-7058
[6]
Hu, J.; Tsai, H. L.; Wang, P. C. (2006). [ASME ASME 2006 International
Mechanical Engineering Congress and Exposition - Chicago, Illinois, USA
(November 5 – 10, 2006)] Heat Transfer, Volume 2 - Effects of Welding
Current on Metal Transfer and Weld Pool Dynamics in Gas Metal Arc
Welding. , 2006(), 637–645. doi:10.1115/imece2006-15617
[7]
J. Amos Robert and N. Murugan, Investigations on the influence of
surfacing process parameters over bead properties during stainless steel
cladding, Materials and Manufacturing Processes, 27 (2012) 69-77
[8]
What are stickout, electrode extension and contact-tip-to-work distance?
Miller Electric. (2022, April 13). Retrieved June 2, 2022, from
https://www.millerwelds.com/resources/article-library/what-are-stickoutelectrode-extension-and-contact-tip-to-workdistance#:~:text=The%20original%20contact%2Dtip%2Dto,of%20spec%
20for%20the%20application.
41
[9]
Kumar, V. | L. (n.d.). CRA weld overlay - dilution and corrosion resistance.
TWI. Retrieved June 2, 2022, from https://www.twi-global.com/technicalknowledge/published-papers/cra-weld-overlay-influence-of-weldingprocess-and-parameters-on-dilution-and-corrosion-resistance
[10]
Ferrite content in austenitic stainless steels. NeoNickel. (2019, February
14). Retrieved June 8, 2022, from https://www.neonickel.com/technicalresources/general-technical-resources/ferrite-content-austenitic-stainlesssteels/
[11]
B. S. Rho, H. U. Hong and S. W. Nam, The effect of δferrite on fatigue
cracks in 304L steels, International Journal of Fatigue, 22 (2000) 683-690.
[12]
S. Lia, Z. Eliniyaza, L. Zhanga, F. Suna, Y. Shenb and A. Shana,
Microstructural evolution of delta ferrite in SAVE12 steel under heat
treatment and short-term creep, Material Characterization, 73 (2013)144152
[13]
R. Puli and G. D. J. Ram, Corrosion performance of AISI 316L friction
surfaced coatings, Corrosion Science, 62 (2012) 95-103
[14]
S. H. Kim, H. K. Moon, T. Kang and C. S. Lee, Disssolution kinetics of
delta ferrite in AISI 304stainless steel produced by strip casting process,
Materials Science and Engineering, A356 (2003) 390-398
[15]
M.A. Wahab,6.03 - Manual Metal Arc Welding and Gas Metal Arc Welding,
Editor(s): Saleem Hashmi, Gilmar Ferreira Batalha, Chester J. Van Tyne,
Bekir Yilbas, Comprehensive Materials Processing, Elsevier, 2014, Pages
49-76,ISBN 9780080965338,https://doi.org/10.1016/B978-0-08-0965321.00610-5.
[16]
Ebrahimnia M, Goodarzi M, Nouri M, Sheikhi M (2009) Study of the effect
of shielding gas composition on the mechanical weld properties of steel ST
37–2 in gas metal arc welding. Mater Des 30 (9):3891–3895.
doi:10.1016/j.matdes.2009.03.031
[17]
ASM International. Handbook Committee. Knovel (Firm) (1993) ASM
handbook. Volume 6, Welding, brazing, and soldering
[18]
Davies AC (1993) The science and practice of welding, 10th edn.
Cambridge University Press, Cambridge, pp 114–121
[19]
Filho DF, Ferraresi VA (2010) The influence of gas shielding composition
and contact tip to work distance in short circuit metal transfer of ferritic
stainless steel. Weld Int 24(3):206–213. doi:10.1080/09507110902843842
[20]
Cay VV, Ozan S, Gok MS (2011) The effect of hydrogen shielding gas on
microstructure and abrasive wear behavior in the surface modification
42
process using the tungsten inert gas method. J Coat Technol Res 8(1):97–
105
[21]
Gülenç B, Develi K, Kahraman N, Durgutlu A (2005) Experimental study of
the effect of hydrogen in argon as a shielding gas in MIG welding of
austenitic stainless steel. Int J Hydrog Energy 30 (13–14):1475–1481.
doi:10.1016/j.ijhydene.2004.12.012
[22]
Sathiya P, Aravindan S, Soundararajan R, Noorul Haq A (2009) Effect of
shielding gases on mechanical and metallurgical properties of duplex
stainless-steel welds. J Mater Sci 44(1):114–121. doi:10.1007/s10853008-3098-8
[23]
Tseng KH, Chou CP (2002) Effect of nitrogen addition to shielding gas on
residual stress of stainless steel weldments. Sci Technol Weld Join
7(1):57–62. doi:10.1179/136217101125000505
[24]
Feritscope FMP30 measurement of the ferrite content - Helmut Fischer.
(n.d.).
Retrieved
June
2,
2022,
from
https://www.helmutfischer.com/fileadmin/content/1-filebase/3-products/2-pdf/2portable/en/BROC_FMP30_FERITSCOPE_902-039_en.pdf
[25]
Prabhu, R.; Alwarsamy, T. (2017). Effect of process parameters on ferrite
number in cladding of 317L stainless steel by pulsed MIG welding. Journal
of Mechanical Science and Technology, 31(3), 1341–1347.
doi:10.1007/s12206-017-0234-x
43
APPENDICES
Turnitin results
44