v
TABLE OF CONTENT
ABSTRAK i
ABSTRACT ii
DEDICATION iii
ADKNOWLEDGEMENT iv
TABLE OF CONTENT v
LIST OF TABLES ix
LIST OF FIGURES x
LIST OF APPENDICES xii
LIST OF ABBREVIATIONS xiii
CHAPTER 1: INTRODUCTION 1
1.1 Background Study
1 1.2 Problem Statement
2 1.3
Objectives 3
1.4 Scope of Study
4 1.5
Project Outline 5
1.6 Activity Planning
6
CHAPTER 2: LITERATURE REVIEW 7
2.1 Stainless Steels
7 2.1.1
Martensitic Stainless Steel 8
2.1.2 Ferritic Stainless Steel
9 2.1.3
Duplex Stainless Steel 9
2.1.4 Precipitation-Hardening Stainless Steel
10 2.1.5
Austenitic Stainless Steel 11
2.2 Austenitic Stainless Steel 300 series
11 2.2.1
AISI 304 and AISI 316L 12
2.3 Dissimilar Metal Welding
13 2.4
Wire Electrode Selection 14
2.5 Orbital Pipe Welding
15
vi 2.6
Type of Welding Process 17
2.6.1 GTAW
17 2.6.2
FCAW 18
2.6.3 GMAW
18 2.7
Orbital GMAW 19
2.7.1 Process Variables
20 2.7.1.1
Arc Current 20
2.7.1.2 Arc Voltage
21 2.7.1.3
Welding Speed 22
2.7.1.4 Wire Feed Speed
22 2.7.1.5
Shielding Gas 23
2.7.1.6 Wire Electrode Diameter
23 2.7.2
Process-Properties Relationship 24
2.7.3 GMAW Metal Transfer Mode
26 2.7.3.1
Short Circuit Transfer 26
2.7.3.2 Spray Arc Transfer
27 2.7.3.3
Globular Transfer 28
2.8 Repair Welding
29 2.9 Non-Destructive Testing
30 2.9.1 Liquid Dye Penetrant Testing
30 2.10
Mechanical Testing 32
2.10.1 Microhardness Testing
32 2.10.2
Tensile Testing 33
2.11 Metallographic Analysis 34
2.12 Microstructural Evolution
35 2.12.1
Microstructure Morphology 35
2.12.2 Volume Frac
tion of δ-ferrite 37
2.13 Mechanical Properties
38 2.13.1
Hardness 38
2.13.2 Tensile Properties
39 2.14
Summary 40
vii
CHAPTER 3: METHODOLOGY 41
3.1 Flow Chart
42 3.2
Basic Material Selection 45
3.2.1 Pipe Specimens
45 3.2.2
Wire Electrode 46
3.3 Material Preparation
46 3.4
Equipment Set Up 48
3.5 Repair Welding Process
49 3.6
Test Specimen Preparation and Weld Joint Testing 51
3.6.1 Liquid Dye Penetrant Testing
51 3.6.2
Metallographic and Microhardness Specimens Preparation 53 3.6.2.1
Metallography Examination 53
3.6.2.2 Vickers Microhardness Testing
54 3.6.3
Tensile Specimen Preparation 55
3.6.3.1 Tensile Testing
56
CHAPTER 4: RESULTS AND DISCUSSION 58
4.1 Liquid Dye Penetrant Testing
59 4.2
Macrostructural Characterization 61
4.3 Microstructural Characterization
62 4.3.1
Base Metals 63
4.3.2 Fusion Zone
63 4.3.3
Heat Affected Zone HAZ 65
4.4 Microhardness Testing
68 4.4.1
Base Metals 68
4.4.2 As-welded Specimen and Repaired Specimens
69 4.5
Tensile Testing 74
4.5.1 Base Metals
74 4.5.2
As-welded Specimen and Repaired Specimens 75
CHAPTER 5: CONCLUSIONS AND RECOMMENDATIONS 78
