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STUDENT INDUSTRIAL PROJECT REPORTJANUARY 2014 – APRIL 2014

The Analysis of Welding Procedure and Welding Procedure

Qualification Test

Name: Khairil Anwar B. Muhajir

SID: 14799

Course: Chemical Engineering

Host Company: True Feature Corporation Sdn. Bhd.

Host Company Supervisor: Mr. Nazri B. Nawi

UTP Supervisor: Dr Nurlidia Bt Mansor



I

HOST COMPANY VERIFICATION STATEMENT

I hereby verify that this report was written by:

Name: Khairil Anwar B. Muhajir

IC Number : 921203-10-5061

and all information regarding this company and the project involved are NOTconfidential.

Host Company Supervisor’s stamp

and signature

Name: Nazri Bin Nawi

Designation: Quality Assurance Quality Control

Host Company: True Features Corporation Sdn.

Bhd.

Date: 6/8/2014



II

HOST COMPANY’S VERIFICATION

STATEMENT

I hereby verify that this report was written by

NAME : KHAIRIL ANWAR B. MUHAJIR

IC NUMBER : 921203-10-5061

and all information regarding this company and the projects involved are NOT

confidential.

However, this document is subject to the Universiti Teknologi PETRONAS and True

Features Corporation Sdn. Bhd. policy and shall be treat as educational reference

only.

HOST COMPANY

SUPERVISOR’S SIGNATURE

& STAMP

NAME Nazri Bin Nawi

DESIGNATION Quality Assurance & Quality Control

HOST COMPANY True Features Corporation Sdn. Bhd.

DATE 6/8/2014



III

ACKNOWLEDGEMENT

My deepest gratitude to Allah The Most Gracious and Merciful, for the

guidance and blessings, for providing me strength whenever the hopes seem

vanished. The author would like to thanks to En. Nasrul Adli (Engineering Manager)

for being proactive in helping and providing support throughout the 14 weeks of

internship training period. It has been a remarkable experience to work under his

supervision because the best opportunity granted upon the author regarding the

experience real life problems and work technical knowledge.

High sincere appreciation is dedicated to En. Hafizul Mohamad (QA & QC),

En. Shariff Yusoff (QA & QC), En. Nazri Nawi (QA & QC), En. Hafiz Daud (QA &

QC), En. Hossein Onn (Senior Welder), as well to all staff of True Features

Corporation Sdn. Bhd, Star Kris Services Sdn. Bhd. and CETCO Oilfield Sdn. Bhd

for their continuous support, guidance and contribution toward the successfulness of

the training program. Without the contribution from the various people mention,

author would doubt to success in achieving the objective of the industrial internship

program.

Deepest thanks to the workforce of TFCSB staffs for be openly embrace my

existence as part of their colleague and their readiness in giving guidelines and

knowledge as well sharing their working experience which really an giving deepest

insight upon my future employment and making my internship period as priceless

experience. Although, the course taken by the author in the university is not really

compatible with the fabrication piping and skid field work, however, with the

enthusiasm in helping by the staffs, the author manage to adapt and learn the new

knowledge which not related with the course taken in the university.

Last but not least, author would like to give a special credit to Dr Nurlidia

who has been appointed as the author UTP’s supervisor for allocating her time from

her hectic schedule to evaluate author performance and sharing information on

internship matters in ensuring my 14 weeks training period going on smoothly. With

her supervision, the author would doubt to achieve the goal setting by Universiti

Teknologi PETRONAS for this industrial training internship. With countless helps

and supports from them, thus completing the industrial internship program.



IV

LIST OF CONTENT

List of Figures VList of Tables V

List of Abbreviations VICHAPTER 1 Abstract & Introduction 11.1 Introduction of Internship Training Project 11.2 Objectives 21.3 Scope of Study 31.4 Problem Statements 71.5 Relevancy of the Project 9CHAPTER 2 Background & Literature Review 102.1 Feasibility of the Project within the Scope and Time Frame 102.2 Critical Analysis Literature 11

2.2.1 Theory of Welding 112.2.1.1 Type of Joint 11

2.2.1.2 Category of Welding 122.2.1.3 Factor of Weld Joint Strength 122.2.1.4 Weld Accessibility 132.2.1.5 Type of Welding Process 132.2.1.6 Section of A Weld 202.2.1.7 Types of Weld 21

2.2.2 Theory of Electrode 232.2.2.1 Type of Electrode 24

2.2.3 Metal Classification 252.2.4 Welding Testing 26

CHAPTER 3 Methodology 323.1 Research Methodology 32

3.1.1 Data collection 333.1.2 Conducting WPQT and Mechanical Testing 333.1.3 Results from Testing 343.1.4 Recommendations and Conclusion 34

3.2 Key Milestone 353.3 Gantt Chart 35CHAPTER 4 Results & Discussion 364.1 Data Gathering on the Analysis of Welding Procedure 36

with Heat Effect from Welding4.2 WPQT and Mechanical Testing Result Analysis 44

4.2.1 WPQT Brief Review 44

4.2.2 Mechanical Testing Result 47CHAPTER 5 Conclusion & Recommendations 545.1 Impact 545.2 Relevancy to the Objectives 555.3 Suggested Future Work for Expansion and Continuation 55CHAPTER 6 Safety Training & Value Of The Practical Experience 566.1 Lesson Learned and Experience Gained 566.2 Leadership, Teamwork and Individual Activities 576.3 Business Values, Ethics and Management Skills 586.4 Problems or Challenges Faced and Solutions to Overcome 59REFERENCES 60APPENDICES 61



V

LIST OF FIGURES

Figure 1.1 Picture of skid with its piping.

Figure 1.2 Picture of metal i-beam.

Figure 1.3 Picture of large piping diameter welding.

Figure 1.4 Picture shows sample of RT image with its defect explanation.

Figure 2.1 Picture shows the type of welding joints.

Figure 2.2 Example of welding inaccessibility

Figure 2.3 Diagrams show the section of weld.

Figure 2.4 Picture shows the application of fillet weld in single and double.

Figure 2.5 Picture shows the basic groove weld.

Figure 2.6 Picture shows an example of surfacing weld.Figure 2.7 Picture shows the guided bend test jig.

Figure 2.8 Picture shows the specimen of guided bend test.

Figure 2.9 Picture shows the guided bend and tensile specimen.

Figure 2.10 Picture shows the tensile specimen and tensile test method.

Figure 3.1 The flow chart show the summary of research methodology

Figure 3.2 The diagram shows the Key milestone for the project.

Figure 4.1 The pictures show process of welding.

Figure 4.2 The picture shows the Weld region.

Figure 4.3 The picture shows the detail of weld region.

Figure 4.4 The picture shows the phase transformation diagram of C-Fe.

Figure 4.6 The figure shows the position of 3G welding.

Figure 4.7 The figure shows the dimension of the groove weld for this WPQT.

Figure 4.8 The figure shows the weld beads done by the welder.

Figure 4.9 The figure shows the specimens for the tensile testing.

Figure 4.10 The figure shows the specimens fractured.

Figure 4.11 The figure shows the machine for the tensile test.

Figure 4.12 The figure shows the specimen for the bending test.

Figure 4.13 The figure shows the machine used for the bend test.

Figure 4.14 The figure shows the specimen after the bending test.

Figure 4.15 The figure shows the cross sectional of weld part.

Figure 4.16 The position of the location of the pressed needle on the metal.



VI

LIST OF TABLES

Table 3.1 The table shows the Gant Chart for this project.

Table 4.1 The table shows the welding defects, causes and their remedies.

Table 4.2 The table shows the result of the tensile testing.

Table 4.3 The table shows the result of the bend testing.

Table 4.4 The table shows the result of the Charphy Test.

Table 4.5 The table show the result of Vicker's Hardness Test.

LIST OF GRAPH

Graph 4.1 The graph shows the result of the tensile testing of the metals.

LIST OF ABBREVIATION

UTP Universiti Teknologi PETRONAS

SIP Student Industrial Project

SIT Student Industrial Training

TFCSB True Features Corporation Sdn. Bhd

QAQC Quality Assurance Quality Control

AFC Approved for Construction

NDT Non-destructive Test

RT Radiographic Test

UT Ultrasonic Test

DPI Dye Penetration Inspection

MPI Magnetic Particles Inspection

WPS Welding Procedure Specification

WPQT Welding Procedure Qualification Test

WQR Welding Qualification Record

IMS Introduction to Material Science

CSIMAL Centre for Student Internship, Mobility And Adjunct Lectureship

Nusatek Nusantara Technologies Sdn. Bhd

GTAW Gas Tungsten Arc Welding

GMAW Gas Metal Arc WeldingHAZ Heat Affected Zone



1

CHAPTER 1

ABSTRACT AND INTRODUCTION

1.1 Industrial Internship Training Program

In order to achieve the Universiti Teknologi Petronas (UTP) which is to

produce well rounded graduates defined as those who possesses lifetime learning

capacity, critical thinking, technical competence, practical aptitude and solution

synthesis ability, an industrial training period is introduce and a compulsion for

student in completing studies in UTP. In order to achieve its objectives,

undergraduate students must experience the practical work as to implement their

theoretical technical knowledge gather from the class through the industrial

internship program.

In cooperation with the industry and government sectors, UTP managed to

supply their interns to pursue their experience which compatible with their course

program in UTP. This cooperation is essential in order to produce the fresh graduated

which comply with the university standards as well as the market jobs requirements.

The purpose of the Student Industrial Project (SIP) is to provide exposure to

students of Universiti Teknologi PETRONAS (UTP) on reality of working

environment so can apply the theoretical knowledge in the industry. Another purpose

from the SIP, the student will acquire the skills in safety practices, work ethics,

communication, management, etc. Apart from that, SIP will strengthen the

relationship between the industry and UTP. SIP also will help students to have a

solid understanding of business fundamental and organization performance such as

business economic model, competitive positioning and strategic implementation.

Their ability to assess performance, synthesis best decision, explore the consequence

of change and interpret trends will be developing with the exposure of the real life

working environment. As an equivalent benefits from this cooperation, the company

will have opportunity to survey the future potential employees boosting the

productivity of the company. SIP also allows the industry in contributing toward

education sector which build up the company’s reputation among graduates for its

deeds in developing human capital for nation.



2

In this report will encloses all the related activities done by the author in

completing author’s project throughout the industrial project at True Features

Corporation Sdn. Bhd (TFCSB). This chapter begins with a brief description upon

the industrial project and its purposes. After that, it will expend clarifying the

project’s objectives followed by stating the problem statements and defining the

scope of study. It will end by discussing the relevancy of this chapter.

After the first half of internship period, the author has been transferred to the

Quality Control and Quality Assurance (QAQC) team who particularly deal with the

procedure and specification of the projects. Apart from that, QAQC is responsible in

monitoring the welding process quality and eliminate any defects of the welding thus

ensuring the equipment welding structure is strong enough according to the projectspecification requested by the client. The author has received useful lessons from

involving the inspection conducted by the Quality Control Engineer, tasks, as well as

receiving intensive explanations from the supervisor himself.

After consultation with supervisors from TFCSB and UTP, the author

decided to carry out his SIP with the title ‘Analysis of Welding Process and Welding

Procedure Qualification Test’. The project comprises of technical understanding ofthe Welding Procedure Specification itself; requirement of the process according to

the project specification, analysis of the material state due to heating application.



3

1.2 Objectives

The objectives of this project are:

To analyse the welding process in term of heating effect on the strength of the

material.

To understand the importance of the Welding Procedure Specification in

fabrication process of the projects.

1.3 Scope of Work, Tasks or Project Undertaken

True Features Corporation Sdn. Bhd. (TFCSB) is a local based company

which produces equipment for the clients in the oil and gas industry. TFCSB is metal

fabrication company which specialise in oil and gas equipment. The core business of

the TFCSB is the fabrication of metal piping and skid which include the purchasing

materials used for piping and skid, assembling the components, installation of

pressured and non-pressured vessel and internal and external quality check for the

piping and skid in order to ensure the piping and skid follow with the international

standard of oil and gas sector.

TFCSB produces skid and pipeline for various function of oil and gas sector.

Skid is a type of pallet, a metal, wood or plastic platform for holding machinery or

equipment while pipeline is refer to the piping system that applied to the equipment.TFCSB will produce the skid and pipeline with provided the equipment by the

customers according to the international standard requirement decided by the

customers. It can be design according the demand of the customers.



4

Figure 1.1 Picture of skid with its piping.

In fabrication, it consists of process of cutting, assembling and welding of the

materials. Cutting is a process of preparation of materials before it is rearrange

according to the drawing and being welded. In this process, the materials are cut into

designated pieces according to the Approved for Construction (AFC) drawing by the

clients. The materials usually used in the fabrication for TFCSB is i-beam, square

hollow, angle bar, c-channel and metal plate. Each of materials has different

characteristics which have distinctive function.

Figure 1.2 Picture of metal i-beam.



5

Welding process is a process where the materials are fused together following

the approved drawing. In this process, it has two phases which are fit up phase and

full welding phase. Fit up phase is a temporary welding before the joint are approved

following the AFC drawing of the equipment. Sometimes in this process, the

equipment which has been done fit up need to be witnessed and examined the third

party company representative. This happened when the clients requested for third

party to check the accuracy of the dimension of the fit up material at critical part

such as lifting parts.

Figure 1.3 Picture of large piping diameter welding.

After the third party satisfied with the dimension of the fit up, the material

can be fully welded. The complete welded materials are then being examined using

Non-Destructive Test (NDT) which are Magnetic Particles Inspection (MPI),

Radiagraphic Testing (RT), Ultrasonic Testing (UT) and Dye Penetration Inspection

(DPI). These testing is a mechanism to check whether the welding joint are truly

strong enough without any defects which later on will be discuss in critical literature

part. If the NDT inspector confirm there is no defect spotted, the assembling process

will then followed by. In the assembling process, the complete welded parts are

assembled together according to the AFC drawing.



6

Figure 1.4 Picture shows sample of RT image with its defect explanation.

However, the scope of study for this project will only cover the welding part only. It

covers the following:

1) Understanding the concept of welding

2)

Understanding types and methods of welding

3) Understanding the defects of welding and major catastrophe disaster due to

those defects.

4)

Describing the significance of Welding Procedure Specification (WPS),

Welding Procedure Qualification Test (WPQT) and Welder Qualification

Record (WQR).

5) Obtaining the data from the WPS and the mechanical testing by the welding

inspection company upon the welded metals.

6) Analyse the effects of heat from the welding procedure on the strength of

combination different metals.

7)

Obtaining the data from the WPS and the mechanical testing by the welding

inspection company upon the welded metals.



7

1.4 Problem Statement

Many processes of engineering like welding, fabrication which involves

cutting, bending, and assembling of metals require high attention and expertise to

carry out the processes without causing any harm. Welding is the process of

fabrication that joins materials by causing coalescence which can be produced by

melting the work pieces or different metal parts and adding a filler material between

them which then forming a pool of molten materials that cool down becoming a

strong joint. In the early year of welding, it was carried out by blacksmiths to make

ornaments by doing such melting and joining processes. It is believed that welding

has been discovering which date back to thousands of years ago.

During that time, the welding method was known as forge welding which

simply involved the heating of two metal surfaces and hammering them together.

Only 19th Century, the welding that we know as today is discovered. It then advanced

quickly during the early 20th Century as World War I and World War II erupted and

drove the demand for reliable and cheap joining methods. We should realise that

many structures would not existed without this form of metal work. In most industry

such as the automotive industry, the construction industry and even the aviation

industry, welding is an absolutely essential component. Imagine, even the oil rigs is

build up by various forms of welding in order to withstand the harsh oceanic weather

conditions.

Poor welding will lead to the destruction of the equipment which also will

harm the user. Let’s tak e example on study case of breakdown in lower gate of

Danube lock chamber and UMM Said NGL Plant Qatar 3rd.

Umm Said NGL Plant, Qatar 3rd

In April 1977, a tank of 260,000 barrels containing about 236,000 barrels of

refrigerated propane at -44oC failed. The wave of liquid propane swept over the dikes

and inundated the 51,000-barrel-per-dayprocess area before igniting. The other tank

containing 125,000 barrels of refrigerated butane also destroyed. The fire burned out

of control for two days and can be extinguished after eight days later. It was reportedthat the fail tank had been repaired due to welding failure a year earlier causing



8

14,000 barrels of propane released to the atmosphere. Another factor of contribution

to this 3rd April 1977 was micro-biological sulphate reducing bacteria from

hydrotesting the tank with sea water. A massive vapour cloud travelled 500 feet in

the first incident. Only six people were killed in the accident and damage inflicted to

the property was estimated at $76 million in 1977 which is equal to $179 million

nowadays.

Breakdown in lower gate of Danube lock chamber

A serious breakdown occurred in the left gate lock of Gabčíkovo dam lock

chamber resulted in shut down of ship transport through the lower section of Danube

river for more than five weeks. The steel structure gate was made up of welded boxdesign of considerable size (18.5 m width, 95m height and 2 mm minimal thickness).

After the analysis, the gate breakdown took place in brittle mode. The steel used was

a high strength (S530Q) low-alloy Cr-Mo-B type with unfavourable high carbon

equivalent of Ce = 0.79 to 0.82. It was believed that the breakdown fractures started

from the cracks in welded joint end up causing the cold, hydrogen induced cracks

are cornered which were formed due to insufficient preheat temperature applied in

welding. This is proved also by the presence of martensitic structure in the HAZ.These cold cracks with inter-crystalline surface appearance at repeating cyclic

loading of the gate propagated by the mechanism of low-cycle (high-strain) fatigue

with typical striations and openings of the elongated inclusions till they attained the

critical size, when they followed in a sudden brittle fracture of a limited length with

the characteristic river morphology.



9

1.5 Relevancy of the project

Welding process is important to the fabrication field as it comprises most of

the jobs of the fabrication production line. Without welding process, the materialcannot be fused together to form all the skid and even joining the piping. Thus, the

welding process will determine the strength and the longevity of the equipment.

Many researches are done in order to increase the strength of the welding.

Since the welding is important in our life, the welding quality is very crucial

to ensure the equipment or products strong enough to use and avoid any accident and

injury on the users. Thus, the welder need to be examined before allowed to the

welding process for the assigned project. The welder is being tested in Welding

Procedure Qualification Test (WPQT). WPQT is a test for welder to be qualified for the

welding job of the project. In order to pass the test, the welder needs to follow Welding

Procedure Specification (WPS).

WPS is a formal written document which describing the welding procedure

providing direction to the welder or welding operators in order to produce good

quality welds as per the code requirements. The document works as guidance for the

welders to be accepted with the procedure so that repeatable and trusted welding

techniques are used. This welding test is then record into Welding Procedure

Qualification Record (WPQR).

WPQR is a record of a test weld performed and tested in order to produce a

definite good weld. The certified welder will then will be recorded into Welder

Qualification Test Record (WQTR). This document will show that the welder has the

understanding and possess the ability to work within the specified WPS. The analysis

from this project will be used to give the idea and suggestion for improvement for

upcoming WPQT which conducted by the Quality Control Engineer (QC).

In terms of the Chemical Engineering course, this project will be considered

as a relevant to the course since the analysis will be involve with characteristic of the

metals, heat effects and the strength of the metal joint which mainly touch in the

subject of Introduction to Material Science (IMS)



10

CHAPTER 2

BACKGROUND AND LITERATURE REVIEW

2.1 Feasibility of the project within the scope and time frame

Within the 28 weeks duration of the internship period starting from 20 th

January 2014 to 22nd August 2014, the author is actively involved in many projects

since being assigned as Project Engineer and later being transferred into Quality

Control Quality Assurance (QAQC) department. This opportunity gives the author to

access some documents of projects which giving the idea for this project. The

proposed project title was submitted to CSIMAL between week 2 and 3 during SIT.

Internship coordinator from Chemical Engineering department reviewed and

approved the proposed project title before SIP begins. The idea of this project is

proposed by Mr. Hafizul during the casual discussion with him. Welding is main part

of the production line of the fabrication company which make the project is highly

related with the core business of the company.

The project will require the author to involve in the WPQT which can be

done by a day. The author needs to gather all the data for WPS and WPQR. This data

later will be used in the further analysis. Next, the metal joint needs to be examined

and tested in order to check whether the welded metal passed the requirement of the

code. This testing was conducted in Nusantara Technologies Sdn. Bhd (Nusatek).

This company are specialised in doing the mechanical testing and non-destructive

test. In order to increase the understanding on the mechanical testing which will be

required in this project, the author witnessed the mechanical testing conducted. Later

after few days, Nusatek produced the reports and documented in the project file. The

analysis took place after all the reports already done. Since the duration of SIP is 14

weeks and the report shall be submitted to CSIMAL in week 13, the author only has

less than 13 weeks to comprehend the analysis of the welding procedure.



11

2.2 Critical Analysis Literature

2.2.1 Theory of Welding

Welding is any metal joining process wherein coalescence is produced by

heating the metal to suitable temperatures, with or without the application of pressure

and with or without the use of filler metals.

2.2.1.1 Type of Joint

Welds are made at the junction of the various pieces that make up the

weldment. The junctions of parts, or joints, are defined as the location where two or

more numbers are to be joined. Parts being joined to produce the weldment may be

in the form of rolled plate, sheet, shapes, pipes, castings, forgings, or billets. The five

basic types of welding joints are listed below.

Figure 2.1 Picture shows the type of welding joints.



13

2.2.1.4 Weld Accessibility

The weld joint must be accessible to the welder using the process that is

employed.

Figure 2.2 The example of the welding inaccessibility.

2.2.1.5 Type of Welding Process

There are two types of welding process which are Arc Welding and Gas Welding.

Arc Welding

The term arc welding applies to a large and varied group of processes that use

an electric arc as the source of heat to melt and join metals. In arc welding processes,

the joining of metals, or weld, is produced by the extreme heat of an electric arc

drawn between an electrode and the work piece, or between two electrodes. The

formation of a joint between metals being arc welded may or may not require the use

of pressure or filler metal.



14

The arc is struck between the work piece and an electrode that is

mechanically or manually moved along the joint, or that remains stationary while the

work piece is roved underneath it. The electrode will be either a consumable wire rod

or a non-consumable carbon or tungsten rod which carries the current and sustainsthe electric arc between its tip and the work piece. When a non-consumable electrode

is used, a separate rod or wire can supply filler material, if needed. A consumable

electrode is specially prepared so that it not only conducts the current and sustains

the arc, but also melts and supplies filler metal to the joint, and may produce a slag

covering as well.

a. Metal Electrodes. In bare metal-arc welding, the arc is drawn between a bare or

lightly coated consumable electrode and the work piece. Filler metal is not obtained

from the electrode, and neither shielding nor pressure is used. This type of welding

electrode is rarely used, however, because of its low strength, brittleness, and

difficulty in controlling the arc.

(1) Stud welding. The stud welding process produces a joining of metals by heating

them with an arc drawn between a metal stud, or similar part, and the work piece.

The molten surfaces to be joined, when properly heated, are forced together under

pressure. No shielding gas is used. The most common materials welded with the arc

stud weld process are low carbon steel, stainless steel, and aluminium.

(2) Gas shielded stud welding. This process, a variation of stud welding, is basically

the same as that used for stud welding, except that an inert gas or flux, such as argon

or helium, is used for shielding. Shielding gases and fluxes are used when welding

nonferrous metals such as aluminium and magnesium.

(3) Submerged arc welding. This process joins metals by heating them with an arc

maintained between a bare metal electrode and the work piece. The arc is shielded by

a blanket of granular fusible material and the work piece. Pressure is not used and

filler metal is obtained from the electrode or from a supplementary welding rod.

Submerged arc welding is distinguished from other arc welding processes by the

granular material that covers the welding area. This granular material is called a flux,

although it performs several other important functions.



15

It is responsible for the high deposition rates and weld quality that

characterize the submerged arc welding process in joining and surfacing applications.

Basically, in submerged arc welding, the end of a continuous bare wire electrode is

inserted into a mound of flux that covers the area or joint to be welded. An arc isinitiated, causing the base metal, electrode, and flux in the immediate vicinity to

melt. The electrode is advanced in the direction of welding and mechanically fed into

the arc, while flux is steadily added. The melted base metal and filler metal flow

together to form a molten pool in the joint. At the same time, the melted flux floats to

the surface to form a protective slag cover.

(4) Gas tungsten-arc welding (TIG welding or GTAW). The arc is drawn between a

non-consumable tungsten electrode and the work piece. Shielding is obtained from

an inert gas or gas mixture. Pressure and/or filler metal may or may not be used. The

arc fuses the metal being welded as well as filler metal, if used. The shield gas

protects the electrode and welds pool and provides the required arc characteristics. A

variety of tungsten electrodes are used with the process. The electrode is normally

ground to a point or truncated cone configuration to minimize arc wandering.

(5) Gas metal-arc Welding (MIG welding or GMAW). In this process, coalescence is

produced by heating metals with an arc between a continuous filler metal

(consumable) electrode and the work piece. The arc, electrode tip and molten weld

metal are shielded from the atmosphere by a gas. Shielding is obtained entirely from

an externally supplied inert gas, gas mixture, or a mixture o f a gas and a flux. The

electrode wire for MIG welding is continuously fed into the arc and deposited as

weld metal. Electrodes used for MIG welding are quite small in diameter compared

to those used in other types of welding. Wire diameters 0.05 to 0.06 in. (0.13 to 0.15

cm) are average. Because of the small sizes of the electrode and high currents used in

MIG welding, the melting rates of the electrodes are very high. Electrodes must

always be provided as long, continuous strands of tempered wire that can be fed

continuously through the welding equipment. Since the small electrodes have a high

surface-to-volume ratio, they should be clean and free of contaminants which may

cause weld defects such as porosity and cracking.



16

(6) Shielded metal-arc welding. The arc is drawn between a covered consumable

metal electrode and work piece. The electrode covering is a source of arc stabilizers,

gases to exclude air, metals to alloy the weld, and slags to support and protect the

weld. Shielding is obtained from the decomposition of the electrode covering.Pressure is not used and filler metal is obtained from the electrode. Shielded metal

arc welding electrodes are available to weld carbon and low alloy steels; stainless

steels; cast iron; aluminum, copper, and nickel, and their alloys.

(7) Atomic hydrogen welding. The arc is maintained between two metal electrodes in

an atmosphere of hydrogen. Shielding is obtained from the hydrogen. Pressure and/or

filler metal may or may not be used. Although the process has limited industrial use

today, atomic hydrogen welding is used to weld hard-to-weld metals, such as

chrome, nickel, molybdenum steels, Inconel, Monel, and stainless steel. Its main

application is tool and die repair welding and for the manufacture of steel alloy

chain.

(8) Arc spot welding. An arc spot weld is a spot weld made by an arc welding

process. A weld is made in one spot by drawing the arc between the electrode and

work piece. The weld is made without preparing a hole in either member. Filler

metal, shielding gas, or flux may or may not be used. Gas tungsten arc welding and

gas metal arc welding are the processes most commonly used to make arc spot welds.

However, flux-cored arc welding and shielded metal arc welding using covered

electrodes can be used for making arc spot welds.

(9) Arc seam welding. A continuous weld is made along faying surfaces by drawing

the arc between an electrode and work piece. Filler metal, shielding gas, or flux may

or may not be used.



17

b. Carbon Electrode.

(1) Carbon-arc welding. In this process, the arc is drawn between electrode and the

work piece. No shielding is use. Pressure and/or filler metal may or may not be used.

Two types of electrodes are used for carbon arc welding: The pure graphite electrode

does not erode away as quickly as the carbon electrode, but is more expensive and

more fragile.

(2) Twin carbon-arc welding. In this variation on carbon-arc welding, the arc is

drawn between two carbon electrodes. When the two carbon electrodes are brought

together, the arc is struck and established between them. The angle of the electrodes

provides an arc that forms in front of the apex angle and fans out as a soft source of

concentrated heat or arc flame, softer than a single carbon arc. Shielding and pressure

are not used. Filler metal may or may not be used. The twin carbon-arc welding

process can also be used for brazing.

(3) Gas-carbon arc welding. This process is also a variation of carbon arc welding,

except shielding by inert gas or gas mixture is used. The arc is drawn between a

carbon electrode and the work piece. Shielding is obtained from an inert gas or gas

mixture. Pressure and/or filler metal may or may not be used.

(4) Shielded carbon-arc welding. In this carbon-arc variation, the arc is drawn

between a carbon electrode and the work piece. Shielding is obtained from the

combustion of a solid material fed into the arc, or from a blanket of flux on the arc,

or both. Pressure and/or filler metal may or may not be used.



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Gas Welding

Gas welding processes are a group of welding processes in which a weld is

made by heating with a gas flame or flares. Pressure and/or filler metal may or may

not be used. Also referred to as oxyfuel gas welding, the term gas welding is used to

describe any welding process that uses a fuel gas combined with oxygen, or in rare

cases, with air, to produce a flame having sufficient energy to melt the base metal.

The fuel gas and oxygen are mixed in the proper proportions in a chamber, which is

generally a part of the welding tip assembly. The torch is designed to give the welder

complete control of the welding flare, allowing the welder to regulate the melting of

the base metal and the filler metal. The molten metal from the plate edges and the

filler metal intermix in a common molten pool and join upon cooling to form one

continuous piece. Manual welding methods are generally used. Acetylene was

originally used as the fuel gas in oxyfuel gas welding, but other gases, such as MAPP

gas, have also been used. The flames must provide high localized energy to produce

and sustain a molten pool. The flames can also supply a protective reducing

atmosphere over the molten metal pool which is maintained during welding.

Hydrocarbon fuel gases such as propane, butane, and natural gas are not suitable for

welding ferrous materials because the heat output of the primary flame is too low for

concentrated heat transfer, or the flame atmosphere is too oxidizing. Gas welding

processes are outlined below.

a. Pressure Gas Welding. In this process, a weld is made simultaneously over the

entire area of abutting surfaces with gas flames obtained from the combustion of a

fuel gas with oxygen and the application of pressure. No filler metal is used.

Acetylene is normally used as a fuel gas in pressure gas welding. Pressure gas

welding has limited uses because of its low flame temperature, but is extensively

used for welding lead.

b. Oxy-Hydrogen Welding. In this process, heat is obtained from the combustion of

hydrogen with oxygen. No pressure is used, and filler metal may or may not be used.

Hydrogen has a maximum flame temperature of 4820°F (2660°C), but has limited

use in oxyfuel gas welding because of its colorless flare, which makes adjustment of

the hydrogen-oxygen ratio difficult. This process is used primarily for welding lowmelting point metals such as lead, light gage sections, and small parts.



19

c. Air-Acetylene Welding. In this process, heat is obtained from the combustion of

acetylene with air. No pressure is used, and filler metal may or may not be used. This

process is used extensively for soldering and brazing of copper piped. Oxy-

Acetylene Welding. In this process, heat is obtained from the combustion ofacetylene with oxygen. Pressure and/or filler metal may or may not be used. This

process produces the hottest flame and is currently the most widely used fuel for gas

welding.

e. Gas Welding with MAPP Gas. Standard acetylene gages, torches, and welding tips

usually work well with MAPP gas. A neutral MAPP gas flame has a primary cone

about 1 1/2 to 2 times as long as the primary acetylene flame. A MAPP gas

carburizing flame will look similar to a carburizing acetylene flame will look like the

short, intense blue flame of the neutral flame acetylene flame. The neutral MAPP gas

flame very deep blue.

Figure 2.3 The diagrams show the section of weld.



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2.2.1.6 Sections of a Weld

a. Fusion Zone (Filler Penetration). The fusion zone is the area of base metal melted

as determined in the cross section of a weld.

b. Leg of a Fillet Weld. The leg of a fillet weld is the distance from the root of the

joint to the toe of the fillet weld. There are two legs in a fillet weld.

c. Root of the Weld. This is the point at which the bottom of the weld intersects the

base metal surface, as shown in the cross section of weld.

d. Size of the Weld.

(1) Equal leg-length fillet welds. The size of the weld is designated by leg-length of

the largest isosceles right triangle that can be scribed within the fillet weld cross

section.

(2) Unequal leg-length fillet welds. The size of the weld is designated by the leg-

length of the largest right triangle that can be inscribed within the fillet weld cross

section.

(3) Groove weld. The size of the weld is the depth of chamfering plus the root

penetration when specified.

e. Throat of a Fillet Weld.

(1) Theoretical throat. This is the perpendicular distance of the weld and the

hypotenuse of the largest right triangle that can be inscribed within the fillet weld

cross section.



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(2) Actual throat. This is distance from the root of a fillet weld to the center of its

face.

f. Face of the Weld. This is exposed surface of the weld, made by an arc or gas

welding process on the side from which the welding was done.

g. Toe of the Weld. This is the junction between the face of the weld and the base

metal.

h. Reinforcement of the Weld. This is the weld metal on the face of a groove weld in

excess of the metal necessary for the specified weld size.

2.2.1.7 Types of Welds

It is important to distinguish between the joint and the weld. Each must be

described to completely describe the weld joint. There are many different types of

welds, which are best described by their shape when shown in cross section. The

most popular weld is the fillet weld, named after its cross-sectional shape. The

second most popular is the groove weld. Other types of welds include flange welds,

plug welds, slot welds, seam welds, surfacing welds, and backing welds. Joints arecombined with welds to make weld joints.

1) Fillet Weld: This is a weld of approximately triangular cross section joining

two surfaces at approximately right angles to each other, as in a lap or tee

joint.

Figure 2.4 The picture shows the application of fillet weld in single or double.



22

2)

Groove Weld: These are beads deposited in a groove between two members

to be joined.

Figure 2.5 The picture shows the basic groove weld.

3) Surfacing Weld: These are welds composed of one or more strings or weave

beads deposited on an unbroken surface to obtain desired properties or

dimensions. This type of weld is used to build up surfaces or replace metal on

worn surfaces.

Figure 2.6 The picture shows an example of surfacing weld.



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2.2.2 Theory of Electrode

When molten metal is exposed to air, it absorbs oxygen and nitrogen, and

becomes brittle or is otherwise adversely affected. A slag cover is needed to protect

molten or solidifying weld metal from the atmosphere. This cover can be obtained

from the electrode coating. The composition of the electrode coating determines its

usability, as well as the composition of the deposited weld metal and the electrode

specification. The formulation of electrode coatings is based on well-established

principles of metallurgy, chemistry, and physics. The coating protects the metal from

damage, stabilizes the arc, and improves the weld in other ways, which include:

(1) Smooth weld metal surface with even edges.

(2) Minimum spatter adjacent to the weld.

(3) A stable welding arc.

(4) Penetration control.

(5) A strong, tough coating.

(6) Easier slag removal.

(7) Improved deposition rate.



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The metal-arc electrodes may be grouped and classified as bare or thinly

coated electrodes, and shielded arc or heavy coated electrodes. The covered electrode

is the most popular type of filler metal used in arc welding. The composition of the

electrode covering determines the usability of the electrode, the composition of thedeposited weld metal, and the specification of the electrode. The type of electrode

used depends on the specific properties required in the weld deposited. These include

corrosion resistance, ductility, high tensile strength, the type of base metal to be

welded, the position of the weld (flat, horizontal, vertical, or overhead); and the type

of current and polarity required.

2.2.2.1 Types of Electrodes.

The coatings of electrodes for welding mild and low alloy steels may have

from 6 to 12 ingredients, which include cellulose to provide a gaseous shield with a

reducing agent in which the gas shield surrounding the arc is produced by the

disintegration of cellulose; metal carbonates to adjust the basicity of the slag and to

provide a reducing atmosphere; titanium dioxide to help form a highly fluid, but

quick-freezing slag and to provide ionization for the arc; ferromanganese and

ferrosilicon to help deoxidize the molten weld metal and to supplement the

manganese content and silicon content of the deposited weld metal; clays and gums

to provide elasticity for extruding the plastic coating material and to help provide

strength to the coating; calcium fluoride to provide shielding gas to protect the arc,

adjust the basicity of the slag, and provide fluidity and solubility of the metal oxides;

mineral silicates to provide slag and give strength to the electrode covering; alloying

metals including nickel, molybdenum, and chromium to provide alloy content to the

deposited weld metal; iron or manganese oxide to adjust the fluidity and properties of

the slag and to help stabilize the arc; and iron powder to increase the productivity by

providing extra metal to be deposited in the weld.



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2.2.3 Metal Classification

There are two types of ores, ferrous and nonferrous. The term ferrous comes

from the Latin word “ferrum” meaning iron, and a ferrous metal is one that has a

high iron content. Nonferrous metals, such as copper and aluminum, are those that

contain little or no iron.

The three commonly used classifications for steel are: carbon, low alloy, and

high alloy. These are referred to as the “type” of steel.

Carbon Steel

Steel is basically an alloy of iron and carbon, and it attains its strength andhardness levels primarily through the addition of carbon. Carbon steels are classed

into four groups, depending on their carbon levels. Low Carbon up to 0.15% carbon

Mild Carbon Steels.15% to 0.29% carbon. Medium Carbon Steels .30% to 0.59%

carbon. High Carbon Steels.60% to 1.70% carbon. The largest tonnage of steel

produced falls into the low and mild carbon steel groups. They are popular because

of their relative strength and ease with which they can be welded.

Low Alloy Steel

Low alloy steel, as the name implies, contains small amounts of alloying

elements that produce remarkable improvements in their properties. Alloying

elements are added to improve strength and toughness, to decrease or increase the

response to heat treatment, and to retard rusting and corrosion. Low alloy steel is

generally defined as having a 1.5% to 5% total alloy content. Common alloying

elements are manganese, silicon, chromium, nickel, molybdenum, and

vanadium. Low alloy steels may contain as many as four or five of these alloys in

varying amounts. Low alloy steels have higher tensile and yield strengths than mild

steel or carbon structural steel. Since they have high strength-to-weight ratios, they

reduce dead weight in railroad cars, truck frames, heavy equipment, etc. Ordinary

carbon steels, that exhibit brittleness at low temperatures, are un reliable in critical

applications. Therefore, low alloy steels with nickel additions are often used for low

temperature situations. Steels lose much of their strength at high temperatures. To



26

provide for this loss of strength at elevated temperatures, small amounts of chromium

or molybdenum are added.

High Alloy Steel

This group of expensive and specialized steels contains alloy levels in excess

of 10%, giving them outstanding properties. Austenitic manganese steel contains

high carbon and manganese levels that give it two exceptional qualities, the ability to

harden while undergoing cold work and great toughness. The term austenitic refers

to the crystalline structure of these steels. Stainless steels are high alloy steels that

have the ability to resist corrosion. This characteristic is mainly due to the high

chromium content, i.e., 10% or greater. Nickel is also used in substantial quantities

in some stainless steels.

2.2.4 Welding Testing

Guided Bend Test

The quality of the weld metal at the face and root of the welded joint, as well

as the degree of penetration and fusion to the base metal, are determined by means of

guided bend tests. These tests are made in a jig. These test specimens are machined

from welded plates, the thickness of which must be within the capacity of the

bending jig. The test specimen is placed across the supports of the die which is the

lower portion of the jig. The plunger, operated from above by a hydraulic jack or

other device, causes the specimen to be forced into and to assure the shape of the die.

To fulfill the requirements of this test, the specimens must bend 180 degrees and, to

be accepted as passable, no cracks greater than 1/8 in. (3.2 mm) in any dimension

should appear on the surface. The face bend tests are made in the jig with the face of

the weld in tension (i.e., on the outside of the bend).



27

The root bend tests are made with the root of the weld in tension (i. e., on

outside of the bend).

Figure 2.7 The pictures show the guided bend test jig.



28

Figure 2.8 The picture shows the specimen of guided bend test.

Figure 2.9 The picture shows the guided bend and tensile test specimen.

The Tensile Test

a. This test is used to measure the strength of a welded joint. A portion of the welded

plate is located at between the jaws of the testing machine. The width thickness of

the test specimen are measured before testing, and the area in square inches is

calculated by multiplying these before testing , and the area in square inches is

calculated by multiplying these two figures. The tensile test specimen is then

mounted in a machine that will exert enough pull on the piece to break the specimen.

The testing machining may be either a stationary or a portable type.



29

As the specimen is being tested in this machine, the load in pounds is

registered on the gauge. In the stationary types, the load applied may be registered on

a balancing beam. In either case, the load at the point of breaking is recorded.

Figure 2.10 The picture shows the tensile specimen and tensile test method.

b. The tensile strength, which is defined as stress in pounds per square inch, is

calculated by dividing the breaking load of the test piece by the original cross section

area of the specimen. The usual requirements for the tensile strength of welds are that

the specimen shall pull not less than 90 percent of the base metal tensile strength.

c. The shearing strength of transverse and longitudinal fillet welds is determined by

tensile stress on the test specimens. The width of the specimen is measured in inches.

The specimen is ruptured under tensile load, and the maximum load in pounds is

determined. The shearing strength of the weld in pounds per linear inch is

determined by dividing the maximum load by the length of fillet weld that ruptured.

The shearing strength in pounds per square inch is obtained by dividing the shearing

strength in pounds per linear inch by the average throat dimension of the weld in

inches. The test specimens are made wider than required and machined down to size.



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Charphy Test

Charphy impact test is a test which the a standard notched specimen taken from the

weld metal is struck with a controlled weight pendulum swung from a set height. The

standard Charphy-V notch specimen is 55 mm long, 10 mm square and has a 2 mm

deep notch with a tip radius of 0.25 mm machined on one face. The specimen is

supported at its two ends on an anvil and struck on the opposite face to the notch by

the pendulum. The amount of energy absorbed in fracturing the test-piece is

measured and this gives an indication of the notch toughness of the test material. The

pendulum swings through during the test, the height of the swing being a measure of

the amount of energy absorbed in fracturing the specimen. Conventionally, three

specimens are tested at any one temperature and the results averaged.

Charpy tests show whether a metal can be classified as being either brittle or ductile.

This is particularly useful for ferritic steels that show a ductile to brittle transition

with decreasing temperature. A brittle metal will absorb a small amount of energy

when impact tested; a tough ductile metal absorbs a large amount of energy. The

appearance of a fracture surface also gives information about the type of fracture that

has occurred; a brittle fracture is bright and crystalline, a ductile fracture is dull and

fibrous. The percentage crystallinity is determined by making a judgement of the

amount of crystalline or brittle fracture on the surface of the broken specimen, and is

a measure of the amount of brittle fracture.

Lateral expansion is a measure of the ductility of the specimen. When a ductile metal

is broken, the test-piece deforms before breaking, and material is squeezed out on the

sides of the compression face. The amount by which the specimen deforms in this

way is measured and expressed as millimetres of lateral expansion



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Magnetic Particle Testing

This is a test or inspection method used on welds and parts made of magnetic

alloy steels. It is applicable only to ferromagnetic materials in which the deposited

weld is also ferromagnetic. A strong magnetic field is set up in the piece being

inspected by means of high amperage electric currents. A leakage field will be set up

by any discontinuity that intercepts this field in the part. Local poles are produced by

the leakage field. These poles attract and hold magnetic particles that are placed on

the surface for this purpose. The particle pattern produced on the surface indicates

the presence of a discontinuity or defect on or close to the surface of the part.

Radiographic Testing or X-ray testing

This is a radiographic test method used to reveal the presence and nature of

internal defects in a weld, such as cracks, slag, blowholes, and zones where proper

fusion is lacking. In practice, an X-ray tube is placed on one side of the welded plate

and an X-ray film, with a special sensitive emulsion, on the other side. When

developed, the defects in the metal show up as dark spots and bands, which can be

interpreted by an operator experienced in this inspection method. Porosity and

defective root penetration as disclosed by X-ray inspection are shown in figure 13-8.



32

CHAPTER 3

METHODOLOGY

3.1 Research Methodology

To ensure the stated objectives can be achieved, the project is done according to theresearch methodologies as follows:

3.1.1 Data Collection

In order to initialise the project, the author need to have a thoroughly view

upon the subject matters in order to understand the project. Thus, the data collection

regarding need to be done by searching many information about welding, metal properties, mechanical testing and heat from welding effect upon metals through

various source namely reference books journals, products catalogues, journals and

project files as well through guidance of fellow colleagues, welders and supervisor.

This process was actively done during the first month of SIP to act as foundation for

the coming attempts.

The data acquired including the theory of welding process in order to

understand the basic concept and idea upon the welding and related matters such as

electrode and technique of welding and also the test which examined the strength of

the welded metals. In additional, the author also did some revision on Introduction to

Material Science to have a flashback which required understanding the metals

properties upon heating as the knowledge is very crucial in order to do the analysis.

These knowledge mentions previously will helps to do the analysis. The

concept of theory of welding process will helps the author to have the idea how the

metal welding done. Since the author did not take any subject related with the

welding, it gives great significance to have the deep understanding on the welding

concept. While the information related with the welding, such as electrode and

welding types is an additional to extend the understanding on welding process.



33

Metals properties knowledge helps to understand how the metal behaviour

upon normal state. Mechanical testing information obtained will be used selection

options of material strength testing to have the most precise and accurate results. In

this project, we did not use any non-destructive test as our material strength testing.

Since the non-destructive test mainly test for the defects of the welding since the

defects of the welding later on will be classified as poor skills welders.

3.1.2 Conducting WPQT and Mechanical Testing

After the Data Collection, the author needs to apply the analysis in some sort

of experiment to develop the study case for the analysis. Since the project isconducted in Fabrication Company and the subject matter for this project is mainly

welding, WPQT was being chosen as method of experiment. WPQT as previously

explained in Relevancy of the Project part, is common procedure which is frequently

taken place in TFCSB. A welder has been selected to weld the different metals which

required following according to the WPS which already being set up by the Quality

Control Engineer (QC) and approved by the client. The author is being assigned to

conduct the WPQT. All the data for the WPQR is recorded such as time taken by the

welder to finish a layer of welding bead.

3.1.3 The Results from the testing

After the WPQT is done, the welded metal is then sent to Nusatek to conduct

mechanical testing. In this testing, the author chooses to attend and witness Nusatek

performing the testing. There are four testing which are Bend Test, Charpy Test,

Tensile Test and Macro Examination. All these tests had already being explained in

the Critical Literature Review. Nusatek will then produce the report for all testing.

The 3rd party company will then review the results and decide whether the welder

can be allowed to pass the WPQT. If the results comply with the code of the

specification, then the welder’s details will be recorded in WQR. This WQR will be

used as a certificate of qualification of doing the welding job for the project. The

report is then being analysis to identify the strength of the welding metals.



35

3.2 Key Milestone

Figure 3.2 The diagram shows the Key milestone for the project.

3.3 Gant Chart

Activities Jan Apr May June July AugIntroduction to TFCSB (Jobscope / Involvement)

SIT Presentation to SV UTP and Company

Confirming SIP Title

Research for Literature Review

- Concept of Welding

- Metal Classification

- Welding Testing

Data Collection

WPQT & Mechanical Testing

Result from TestingCompletion of Report, Documentation

Presentation to SV UTP and Company

Table 3.1 The table shows the Gant Chart for this project.



36

CHAPTER 4

RESULT & DISCUSSION

This chapter compiles the collected data from the previous studies and relevant

findings related to this technology. Firstly, data gathered from the analysis of

welding procedure due to the effect heat from welding are presented, followed by the

WPQT setting specification with its discussion relationship with the previous

analysis. In addition, the result from the mechanical testing will be discussed to

check whether the welding metals have achieved the desirable strength.

4.1 The Data Gathering on the Analysis of Welding Procedure with the heateffect from welding.

Before going into the analysis, it is best to have the idea how the welding is

conducted. Arc welding uses an electrical arc which melts the work pieces as well as

the filler materials, sometimes is known as welding rod to weld the joints. This

welding consists of attaching a grounding wire to the welding material and placing

another wire known as an electrode lead on the material to be welded. After the lead

is pulled away from the material, this will caused an electric arc generated. It's a littlelike the sparks you see when pulling jumper cables off a car battery. The arc then

melts the work pieces along with the filler material that helps to join the pieces. In

order to ensure the detail, the welder needs to have a steady hands and an eye in

feeding the filler into the welding joint. As the rod melts, the welder must

continuously feed the filler into the joint using small, steady, back-and-forth motions

which gives their welds. These motions are what gives welds their distinctive

appearance. Going too fast or slow, or holding the arc too close or far away from thematerial can create poor welds.



37

Figure 4.1 The pictures show process of welding.

Heat is the main component in welding. In order to join two similar or

different metal pieces, the pieces need to be molten to allow the diffusion of the

metal atom of the metal pieces which later on bind the metal pieces into one. The

presence of welding heat creates different region on welding metals. Basically, there

are three regions of a basic weld which are Fusion Zone, Heat Affected Zone and

Base Metal.

Basic Metal Heat Affected Zone

Fusion Zone

Figure 4.2 The picture shows the Weld region.



38

Fusion Zone is the area that is completely melted, while the Heat Affected

Zone is the portion of the base metal not melted but whose mechanical properties and

microstructure were affected by the heat of the joining process. Meanwhile, the Base

Metal is the original metal which is not affected by the heat.

The three regions of the weld can be more finely divided and the distinctions

of where one region ends and another begins is somewhat blurred as indicated above.

The composite region is where the complete mixing occurred between molten base

metal and molten filler metals. While the unmixed region contained only the molten

base metal and happened due to the turbulent stirring in the weld metal. The partially

melted region is a region of fully molten zones and the heat affected zone consisting

the intermittent liquid and solid. On the other hand, the region whose properties or

structure has been affected by the heat of the weld is called True Heat Affected Zone.

Figure 4.3 The picture shows the detail of weld region.



39

The first concern we will consider that occurs in the composite region is

solidification cracking or sometimes called hot cracking. Solidification cracking is

crack happened due to the cooling down temperature of the weld which can be

contributed by weld geometry and impurity elements. Welds with a depth-to-width

ratio greater than 2:1 are susceptible to solidification cracking due to the build-up of

excessive transverse stress. This is especially noted in submerged arc welding,

which exhibits deep penetration.

Excess sulfur and phosphorus drastically lower the solidification temperature

of steel causing complete solidification occurs at a much lower temperature along the

weld center line, where sulfur and phosphorus tend to segregate. As the weld cools,

residual tensile stress develops which leading to centreline cracking due to the high

sulfur and phosphorus areas are weak and may not have completely solidified. In

order to fix the cracked region, it must be cut out beyond the visible end of the crack

and re-welded.

A thermal distribution is set up around the traveling weld in the process of

making a weld. Due to the action of moving thermal gradients, the material expands

and contracts causing the distribution of stress occurred. This stress profile tend to be

compressive in front of the moving weld however behind the weld, it tend to be

tensile where the solidification occurred simultaneously. The factors that affecting

the temperature and stress profiles are overall heats input and preheat and the type of

material welded. In the region of solidification, the tensile stresses become

significant since tends to pull material apart and this would be much trouble in the

hot and weakly solidified areas.

The solidification of welding process is a bit unusual as in within the base

metal contained the liquid weld metal, sort of in its own imaginary very hot mold

which is made up of same or nearly same as the composite weld metal. The

solidification begins at the fusion line where the molten metal and unmelt base metal

meet which also the coolest spot in the weld. This nucleation is called epitaxial

nucleation. The crystal structure present in the hot solid HAZ is transferred to the

initial dendritic crystals which extending into the liquid welds metal. After thenucleation, the dendrite grains continue to grow into the liquid metal. The rate of



40

growth is determined by the favorable orientation which then pinches off the less

favorable one until the entire liquid is consumed. As metal continues to solidify, the

grain in the center become smaller and finer texture compared to the outside

boundary of the weld deposit as the heat from the center of the weld dissipated into

the base metal through the outer grain that solidified first. As the consequence, the

grain that solidified first was at high temperature for a long period in a solid state

which promotes the growth of the grain.

The second element has a limitation on how much it can be absorbed into the

first which is determine on both temperature and the crystal structure present at that

temperature. The diagram below shows this limit of solubility for carbon in iron and

is called the iron-carbon phase diagram. The delta ferrite can only absorb the carbon

about 0.1% where the temperature is maximum carbon content is allowed; while, the

lower temperature ferrite can only absorb 0.02% carbon. In the contrary, the

austenite can absorb more than 1.6% carbon into its lattice structure if only the

temperature is about 2000oF.

Figure 4.4 The picture shows the phase transformation diagram of C-Fe.



41

In order to understanding deeply about the previous analysis, we need to

know how the solidification happened. Solidification is sometimes known as

crystallization process when the molten metal is cooled down, the atoms in the metal

will assemble into a regular pattern of crystal. In this form, the atoms or molecules

are held in fixed positions which are not free to move around like a liquid or gas.

This fixed position is named as a crystal lattice. As the temperature increased, the

absorbed thermal energy will increase causing their movement become ferocious.

The distance between atom increasing and the lattice breaks down while the crystal

starting to melt. If the lattice is only contain a single type of atom such as in pure

iron, the condition will happen to be same at all point throughout the lattice and the

crystal only melts at a single temperature.

In contrary, if the lattice contains more than one types of atoms like in alloy-

steel, the metal may melt at certain temperature however not incomplete melting

until it being heated to a higher temperature. This in another word creating a situation

where there is a combination of liquids and solid together within a range of

temperatures. The crystal structure will become permanent at room temperature

which has varies characteristic depending on the type of the metal. Some metals also

may go into alteration in the crystalline form according to the change of the

temperature. This phenomenon is called phase transformation.

Let’s look the example of pure iron structure. At 1535oC, the pure iron is

solidifies which transform the delta structure into non-magnetic gamma structure

commonly known as austenite. While at 910oC, the pure iron then is return into the

delta structure back however in this temperature is known as alpha iron. The

different name given for these two phases are to differentiate between high

temperature phase (delta) and the low temperature phase (alpha). This capability in

transforming into two or more crystalline structures at different temperatures is

called as allotropic. The examples of allotropic metals are iron and steels.



42

A small group of atom begin to assemble into crystalline form which

scattered throughout the body of the liquid and are oriented in all directions. As

solidification proceeds, more and more crystals are formed and often they begin in

the dendrite form or treelike structure. The crystallization will goes on until at certain

point the growth will thwart as the crystal begin to touch one another, while

remaining liquid freezes to the adjacent crystals until the solidification is complete.

The grain boundary is where the individual crystals meet at different orientations.

There are many factors influence the initial size of the grain, the important factors

that should be known are cooling rate and temperature.

In order to reduce solidification cracking, the filler metals or flux-wire

combinations that result in higher manganese contents are used. The manganese will

reduce the solidification through two mechanisms:

1)

Manganese will combines with sulfur to form manganese sulfide particles.

Since the free segregate at the centerline combine with the manganese, this

will reduce the amount of free sulfur available which causing the lower

solidification temperature leading to low-strength region.

2) Apart from that, as the Manganese atom substitute in the iron crystal

structure, it will strengthen the steel which resulting the weld metal to have

higher strength during the cooling process.

Apart from the defects due to the heating effect of welding, there is other welding

defect cause by other factors. The below table are the list of the other welding

defects, causes and their remedies.



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Type of Defect Causes Remedies

Spatter Welding current too high,

arc too long and

insufficient gas shielding.

Reduce welding current,

reduce arc length and

check shielding gas flow

rate.

Longitudinal Cracks in

HAZ

Base metal undergone

hardening and weld cool

down too rapidly.

Choose material with a

better weldability and

apply a higher preheat.

Lack of fusion defects Heat input too low. Increase the welding

current and slower the

travel speed.

Porosity Moisture and insufficient

gas shielding.

Rebake and check

shielding gas shielding

type and flow rate.

Deformation Too many thin beads and

poor plate fit-up before

welding.

Use a larger electrode and

clamp the work pieces.

Crater cracks Welding ended far too

abruptly.

Move back the electrode

to fill-up the crater.

Undercut Arc voltage too high and

travel speed too high.

Lower arc voltage and

reduce travel speed.

Lack of root penetration Root gap too small and

electrode size too big.

Use wider root gap and

electrode with a diameter

of approximately the gap

width.

Table 4.1 The table shows the welding defects, causes and their remedies.



44

4.2 WPQT and Mechanical Testing Result Analysis

4.2.1 WPQT Brief Review

As explained previously in the Problem State, WPQT is Qualification Test

for welder in order to be certified and granted with the welding job of the project. In

this WPQT, the welder selected to be tested is Thanisorn Butdee. According to the

Project Manager, Mr. Anson, the welder is already selected to be the welder of the

project due to the skills that he has and the availability during the fabrication on

period.

The welder is required to welding two different metals plate sizing of 300mm

x 300mm with 25mm thickness which are stainless steel with carbon steel using two

type of filler rod which are ER309L for GTAW welding and E309L-17 for SMAW

welding. The weld joint must be Butt Weld while the welding process is using

GTAW and SMAW since the metal plates have large thickness. The weld joint needs

to do the backing with the weld metal at the root of the weld. Backing is process of

covering the weld metal between the groove for welding to avoid excess weld at the

root or initial point of welding. As for the groove, the required distance gap is

approximately around 5 mm to 41.24 mm.

The detail of metals properties used is as below:

Carbon Steel (A671)

Mechanical Properties:

Yield Stress: 385 MPa

Tensile Stress: 525 MPa

Elongation: 31%



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Chemical Properties:

Carbon: 0.13%

Silicon: 0.35%

Manganese: 1.5%

Phosphorus: 0.012%

Sulphur: 0.04%

Cromium: 0.013%

Molybdenum: 0.002%

Nickel: 0.13%

Carbon Steel (A240)

Mechanical Properties:-

Yield Stress: 380MPa

Tensile Stress: 480 MPa

Elongation: 29%

Chemical Properties:-

Carbon: 0.2%

Silicon: 0.4%

Manganese: 2.5%

Phosphorus: 0.11%

Sulphur: 0.02%

Cromium: 0.024%

Molybdenum: 0.003%

Nickel: 0.15%



46

According to the WPS document prepared, the position of the groove is 3G

which is all position welding; meanwhile the welding movement is progressing

upward. Before the welding start, the metal pieces need to be prepared by heating to

the ambient temperature in order to remove any absorbed moisture in the metal. The

maximum interpass temperature allowed in less than 300oC however according to the

QC it is supposed to be lowered to 100oC to ensure the weld bead really cool down

before another weld bead is done. Interpass temperature is allowable temperature to

proceed to weld another bead. The gas argon which has 99.9% composition is used

as shielding gas for the GTAW technique. This shielding gas is used to protect the

hot weld is contaminated by the surrounding air.

Figure 4.5 The figure shows the position of 3G welding.

Figure 4.6 The figure shows the dimension of the groove weld for this WPQT.



47

Figure 4.7 The figure shows the weld beads done by the welder.

As for the technique, GTAW and SMAW used weave movement; however

SMAW also used stringer movement. Weave and stringer movement is a movement

of hand during the welding process. Weave movement is a movement of hand in zig-

zag and as for stringer movement is a movement of hand in a straight line. After the

welding while making another layer of welding or weld bead, the weld is required to

do the initial and interpass cleaning. As being decided according with the ASME IV

code, the initial and interpass cleaning used are grinding and brushing.

In order to pass with the this qualification test, the weld metal need to have

higher mechanical properties values Yield, Tensile and Elongation which will be

tested during the mechanical testing.

4.2.2 Mechanical Testing Result

According to the report produced by Nusatek, all the metal is passed with the

requirement. Below are the report produce by the Nusatek:

Tensile Testing:

Table 4.2 The table shows the result of the tensile testing.



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In this tensile testing, the specimen being tested which is taken from the

welded metal is 2 pieces. Each piece has approximately 19mm and 21mm thickness.

The maximum load that is used to pull the specimen is around 216000.00 N and both

have higher tensile strength from the base metal which is 535.79 N/mm2 and 536.01

N/mm2 which fracture at the base metal itself. Thus according to this report, the

welding part of the metal is stronger than the base metal itself.

Graph 4.1 The graph shows the result of the tensile testing of the metals.

The graph above shows the relationship between the lengths of being pulled

and the tensile strength. As you can see, the maximum tensile strength for the metal

is above 210 000 N. When the metal is stretched until 8 mm, the weld metal is started

to resist, the metal become harder to elongate. Until it reach the peak where the metal

is fractured.



49

Figure 4.8 The figure shows the specimens for the tensile testing.

Figure 4.9 The figure shows the specimens fractured.

Figure 4.10 The figure shows the machine for the tensile test.



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Bend Testing:

Table 4.3 The table shows the result of the bend testing.

For the bend testing, there are 4 specimens which is cut it the same dimension

which is 20.62 mm width and 10.00 mm thickness. These specimens are then put into

the machine and bend to check whether there is any visible defect. However, all the

specimens show no visible defect which also passed with the testing.

Figure 4.11 The figure shows the specimen for the bending test.

Figure 4.12 The figure shows the machine used for the bend test.



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Figure 4.13 The figure shows the specimen after the bending test.

Macro Examination:

Figure 4.14 The figure shows the cross sectional of weld part.



52

In the macro examination, the metal is zoomed to 5x across the welding

section in order to see small defects. As you can see the welding part does not have

any defect which is clearly passed with the test.

Charphy Impact Test:

The specimen being prepared is in the form of V-Notch and the sizes are 10 mm x 10

mm x 55 mm. The specimens required for this testing are 9 pieces (3 pieces for the

Weld Metal, while the rest for the HAZ) and being conducted at the temperature -

46oC. In order to pass the test, the minimum lateral expansion needs to exceed more

than 0.38 m. The figure below shows the result of the charphy test.

Table 4.4 The table shows the result of the Charphy Test.

For each notch, the test is repeated for thrice and the result is taken as average in

order to obtain the precise value. In this test, we can find 2 data which are the impactenergy absorbed (Joule) and the lateral expansion (mm). As for the impact test, the

HAZ has the higher impact energy absorbed which is 126.14 J. While as for the

lateral expansion result, all specimens exceed from the requirement which average of

all data is 1.29 mm.

Vicker’s Hardness Test:

In this test, only one specimen is taken from the weld metal. The specimen is then

being pressed by a needle with a force equivalent to 10 kg. Below figures shows the

location of press point and the result of the test.



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Figure 4.16 The position of the location of the pressed needle on the metal.

Table 4.5 The table show the result of Vicker's Hardness Test

In this data, we will determine the depth of needle pressed at each of point with

different location. The data obtain shows that the depth of the needle pressed for this

test is in range of 144 μm to 198 μm which is lower for the requirement which is 230

μm. The test is considered pass.



54

CHAPTER 5

CONCLUSION AND RECOMMENDATION

This chapter concludes the impact of the Analysis of Heating welding on the strength

of the welding metal and also the longevity of the structure equipment. This is

followed by the relevancy to the objectives as stated in Chapter 1. In the last part, the

suggestion for future work for expansion and continuation for this project and the

overall effort of introducing this technology, as a whole.

5.1 Impact

The welding is process is highly demand since the construction of structureinvolving metals and thermoplastic materials is blooming from times to time. Thus,

the needed for improvement in welding materials strength is crucial. This analysis

will increase the understanding how the strength of the metal welding can be

determined and which later on will open up the idea to improve the methods or clear

guideline. Until now, various researches related to welding metallurgy are being

conducted as well as training given to welder and the inspector to inculcate the

awareness regarding this matter. Thus, the welders will know the factors affecting

their welding process that will influence the strength of the welding metal.



55

5.2 Relevancy to the Objectives

To analyse the welding process in term of heating effect on the strength of the

material.

In the discussion part, the heat from the welding process mainly affecting the

strength of the welding metals.

.

To understand the importance of the WPQT in fabrication process of the projects.

The importance of WPQT is already being explained in the problem statements. It

mainly involve with the selection of welder to ensure the welder are really qualified

to the welding job for a project which has their welding specification.

5.3 Suggested Future Work for Expansion and Continuation

In order to have precise analysis regarding the strength of the welding metals,

we need to have a comparison and stating the specific variables such as types of

electrode and the environment surrounding condition in order to prove the theory of

welding and heat effect upon the metal is valid. Apart from that, the analysis needs to

be done according to the ASME or API code which usually use for fabrication

guideline.



56

CHAPTER 6

SAFETY TRAINING & VALUE OF THE PRACTICAL EXPERIENCE

This chapter consists of the lessons learned and experience gained throughout

the industrial internship programme (training and project), leadership, teamwork and

individual activities, business values, ethics and management skills and finally the

review on problem or challenges faced and solutions to overcome them.

6.1 Lesson Learned and Experience Gained

The experience gained from the Industrial Internship Programme (both

Industrial Training and Industrial Project) for 32 weeks are truly wonderful by

author. UTP students can understand the real working nature and blend in to the real

working life and attitude due to the opportunity of having a long internship period. It

is believed that the UTP student practical understand well their job scope and even

working like one of the staffs in the Host Company.

TFCSB has provided awesome experiences during industrial internship from

various technical and non-technical activities. These experiences are gain through the

involvement of author in the company events, engagement with the 3rd party or

clients and also arising problems. In TFCSB, the author learns so many lessons.

Among them are including teamwork, leadership, business understanding, safety

exposure and other which later be explained within this chapter.

Having internship in the fabrication site under the contractor company, the

author learns on how to be professional. Since the assigned job for the author is

Project Engineer which mainly dealing communication with the clients, 3rd parties

and the production teams, the author need to be professional. The author sometimes

needs to learn to open up any criticism on him and always be ready to fix up his

mistakes. He also needs to be truthfully but carefully spare the words as do not to stir

any bigger problems. Project Engineer always plays with due date project which

taught the author to be an organized planner. In order to ensure the project can be

done on time, time management skills is highly required. The author need to learn to prioritize on matter which critical to avoid any time wastage.



57

6.2 Leadership, Teamwork and Individual Activities

Leadership is defined as an ability to lead. In order to become a leader, the

person must know how to manage people, resources and time. At TFCSB, there a

many people which the author can look up to learn the leadership skills such as

staffs, managers and engineers. These people really know how to deal with people

under their command so that they can have a pleasure while performing their tasks.

Good leaders are determined by those who can set the example for everyone else to

follow. One of the example that author notices in TFCSB is a project engineer deals

with superior like a distinguished communicator. Although the age different will be

the possible barrier, however he without any hesitation deliver his point with

firmness and spectacular confidence wisely enough not to offend the senior staff and

getting him cooperation he desired.

Apart from that, teamwork is important to ensure the information is reach to

everyone and useful ideas could be generated collectively to overcome any upcoming

issues. In order to develop a good teamwork, maintaining a good communication

between members is highly important which require good communication skills. In

order to having capability to work in a team, one must possess good skills indelivering insight or ideas clearly to other people. Based on the observation of author

in numbers of meetings attended and individual tasks assigned, a good teamwork will

resolve many problems faced. It is believed that the only way to complete the task

given by communicating with a lot of people, regardless their positions; Project

Manager, Foreman, QC, Welders and even just helpers or fitters. It also enhances the

author’s soft skills.



58

6.3 Business Values, Ethics and Management Skills

It is very crucial for an engineer to develop management skills apart from

having technical skills. It is very important in a professional working environment

and the experiences gained can help to improve and develop existing social skills. In

TFCSB, having excellent work ethic is the priority factor for the staffs. It can show

the actual value of an employee. The best practices of work ethic in TFCSB are

sincerity, punctuality, completion of task in given time, proper dressing and paying

respect to others. Respect is not only paid based on someone’s age or position but

also portrayed in terms of suggestion or giving opinion in a discussion.

Any task given must be done in a specific time. Thus, time management is

very necessary to ensure all the tasks are done before reaching the dateline. Time

management also is a crucial factor that must be taken into consideration in a project

execution because a delay in work progress will not tarnish only the individual’s

reputation, however affecting the whole organization. It can cause a loss in term of

financial and time. Apart from that, one must always have the initiatives to learn

from other credible staffs due to the working environment the scope of knowledge is

wider and beyond our scope of study. By doing this, we will gain advantage by not

restricting the inputs just for our field of study only.

In terms of business values, the author understands the important of ensuring

that the production line to align with the policy of the company in maximising the

profit by avoiding misfits which leading to property damage and workforce injuries.

Thus, the precautionary steps must be taken at all times to prevent any incidents from

occurring and damaging TFCSB’s reputation in the eyes of its clients.



59

6.4 Problems or Challenges Faced and Solutions to Overcome Them

The author faced problems from both technical and non-technical

perspectives in completing the Industrial Internship. These difficulties include

adapting to new environment, technical competencies and time management.

However, the seven months of industrial training and industrial project allowing the

author to understand and develop him to overcome those obstacles. In order to adapt

with the new environment of working life, the author take a few days to familiarize

with the working culture and learning the core business of TFCSB as stated in the

Industrial Training. The situation seem to be alienated since the author’s colleagues

are mostly different field from the author courses, which requires him to learn at the beginning and catch up faster in order to mingle around them. However, their

warmth and kindness in accepting his existence somehow decrease the pressure and

enable him to calm himself. Since the author never learn anything about the

fabrication of piping and skid knowledge which mainly used the mechanical engineer

knowledge, the early period of Industrial Training had been utilised to study more

about the fabrication of piping and skid as well as doing personal research about the

welding process. The urge to learn more has becoming a stepping stone for the

author to step forward and approach his colleagues and supervisor obtain their

technical views and ideas. As the result of the cooperation gain in obtaining data and

information, the author finally managed to finish the SIP report although being

hindered by limited access of information as well as time constraint.



60

REFERENCE

People:

Mr. Nasrul Aidli (Engineering Manager True Features Corporation Sdn. Bhd.)

Mr. Hafizul Mohammad (QA/QC Inspector)

Mohd Sharif Yusoff (QA/QC Inspector)

Nazri Nawi (QA/QC Inspector)

Hossein Onn Sulaiman (Production Site Supervisor)

Websites:

True Features Corporation, Retrieved 2014, from http://www.truefeatures.com/

Universiti Teknologi PETRONAS. (2013). Industrial Internship Guideline for

Students. UTP: Center for Student Internship, Mobility and Adjunct Lectureship(CSIMAL)

Welding, Wikipedia, Retrieved 2014, from http://en.wikipedia.org/wiki/Welding

Welding Procedure Specification, Wikipedia, Retrieved 2014, fromhttp://en.wikipedia.org/wiki/Welding_Procedure_Specification

Grieve, D.J, (February 23, 2009). Welding Processes, Retrieved May 2014, from

http://www.tech.plym.ac.uk/sme/strc201/weld1.htm

Journal:

P. Bernasovský, J. Bošanský: Welding and technological causes of breakdown of the

lock gate of waterwork chamber on Danube river, In: JOM-10 Conference,

Helsingor, 2001

http://www.truefeatures.com/



http://en.wikipedia.org/wiki/Welding



http://en.wikipedia.org/wiki/Welding_Procedure_Specification










61

APPENDICES

Appendix A – The picture of welding defects.

Appendix B – Document of Welding Procedure Specification, Welding Procedure

Qualification Record & Nusatek Mechanical Testing Report.



62

APPENDIX A – THE PICTURE OF WELDING DEFECTS

The picture shows the defect of welding.

The picture shows the porosity in the welding.

industrial project report (wps)

Documents