Production and Weld Joint Performance Evaluation of Arc Welding Electrodes from Dana Rolling Mill Scales
Production and Weld Joint Performance Evaluation of Arc Welding Electrodes from Dana Rolling Mill Scales.
ABSTRACT
This study explored the possibility of producing Iron Oxide based arc welding electrodes using mill scales from Dana rolling mill. The performance of the weld joints using the produced electrodes and a foreign electrode was also examined. It is estimated that 4000-5000 tons of mill scales are produced annually without any immediate industrial application.
The mill scales were collected prepared and analyzed using the Oxford 800 X Supreme XRF machine. The report of the analysis shows the presence of predominantly Iron Oxide, which is an important constituent in electrode coating. The flux compositions were generated using the Hadamard multivariate chemical model. Using this model, twelve different flux compositions emerged within given ranges of the constituent flux elements.
Four of the flux compositions were used to produce electrodes using sodium silicate as binder. The electrodes were produced manually by means of a wooden mould. The produced electrodes (E6020, E6027, E6024 and E6030) and a foreign electrode were used to carry out weld on some prepared samples. The welded joints were tested for tensile, hardness, and impact tests.
The results of the tests conducted on all the welded joints using the produced electrodes and the foreign electrode shows that all the produced electrodes with the exception of electrode type E6030 compete well with the foreign electrode (Oerlikon). Electrode type E6020 gave the highest tensile and hardness test results of 453N/mm2 and 457.1N respectively.
TABLE OF CONTENTS
Contents Pages
Cover Page i
Title Page ii
Declaration iii
Certification iv
Dedication v
Acknowledgement vi
Table of Contents vii
List of Tables xi
List of Figures xii
List of Plates xiii
Abstract xv
CHAPTER ONE
1.0 INTRODUCTION 1
1.1 Overview of Welding 1
1.1.1 Types of welding 2
1.1.2 Types of arc welding 3
1.1.3 Development of welding 5
1.2 Statement of Problem 6
1.3 Present Research 7
1.4 Aim and Objectives 8
1.5 Justification 8
Contents Pages
1.6 Research Scope 9
CHAPTER TWO
2.0 LITERATURE REVIEW 10
2.1 Electrode Overview 10
2.2 Types of Arc Welding Electrodes 12
2.2.1 Consumable electrode s 12
2.2.2 Non consumable electrodes 12
2.3 Classification of Electrode Coatings 12
2.3.1 Gas forming component 13
2.3.2 Slag forming component 13
2.3.3 Reducing component 13
2.3.4 Stabilizing component 13
2.3.5 Binding component 13
2.4 Types of electrode coatings 13
2.4.1 Gas shielded (cellulosic) electrodes 14
2.4.2 Rutile electrodes 14
2.4.3 Iron oxide electrodes 14
2.4.4 Basic electrodes 14
2.5 Review of Related Researches 14
CHAPTER THREE
3.0 MATERIALS AND METHODS 22
Contents Pages
3.1 Introduction 22
3.2 Materials 22
3.3 Equipment 25
3.4 Experimental Procedure 26
3.4.1 Chemical composition formulation process 28
3.4.2 Production process 34
3.4.3 Mechanical tests 36
3.4.4 Production cost determination 37
3.4.5 Estimated cost for the produced electrodes 37
3.5 Sample Preparation 39
3.5.1 Tensile test samples 39
3.5.2 Hardness test samples 41
3.5.3 Impact test samples 42
3.5.4 Metallographic examination 42
CHAPTER FOUR
4.0 RESULTS 45
4.1 Introduction 45
4.2 Results of Mechanical Tests Conducted 45
CHAPTER FIVE
5.0 DISCUSSION OF RESULTS 53
5.1 Elemental Analysis of Mill Scales 53
5.2 Performance Evaluation of Welded Joints 53
5.3 Micrographs of Weldments and Heat Affected Zone 56
CHAPTER SIX
6.0 CONCLUSION AND RECOMMENDATIONS 58
6.1 Conclusion 58
6.2 Recommendations 59
References 60
Appendices 64
INTRODUCTION
Welding is a production or a fabrication process of joining two or more materials together, usually metals or thermoplastics to achieve coalescence. Welding is performed by the application of heat and pressure to melt the work piece together often with the addition of filler material to form a pool of molten material which form the welded joint after solidification (www.metal_processing/welding.cfm).
Many welding processes are accomplished by heat alone, with no pressure applied; others by a combination of heat and pressure; and still others by pressure alone, with no external heat applied. Welding processes are used to produce joints with properties similar to those of materials being joined, these materials are called parent materials.Welding process usually involves raising the materials at the joint to elevated temperature (Ibhadode, 2001).
There are three main components to create a weld and these components are: A heat source: A heat source is an important component in the creation of weld, a heat source include an electric arc, a flame, pressure or friction. However, the most common heat source is the electric. Shielding: Shielding is the use of gas or another substance to protect the weld from atmospheric contamination of the molten.
Filler material: They are used in joining two pieces of materials together, usually metals.Welding is extensively used in fabrication and has found application as an alternative method for casting or forging and as a replacement for bolted and riveted joints. It is also used as a repair medium, for example to reunite metals at a crack, to build up a small part that has broken off, such as gear tooth or to repair a worn surface such as a bearing surface(Khurmi and Gupta, 2005).
REFERENCES
Achebo, J.I. (2009). Development of composition of aluminum welding fluxes using statistical method. Preceding’s of the international multiconference of engineers and computerscientists, Hong Kong, ISBN: 987-988-17012-7-5.
Achebo, J.I. and Dagwa, I.M. (2009).Design, manufacture and performance evaluation of welding electrode coating machine. International journal of applied engineering research.Vol.4(7).
Achebo, J.I. and Ibhadode, A.O.A. (2008).Development of a new flux for aluminum gas welding.Advanced materials research, Switzerland Vol44-46, pp677-684
Achebo, J.I. and Ibhadode, A.O.A. (2009). Determination of optimum Welding flux compositions using the bend strength test technique.Advanced materials research Vol62-64 pp393-397.
Adeyeye, D.A. and Oyawale, F.A. (2008). Mixture experiments and their applications in welding flux design. Journal of the Brazilian society of mechanical sciences andengineeringRio De Jeneiro Vol. 30 No4.
CSN Team.
