MINISTRY OF EDUCATION AND TRAINING HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION GRADUATION THESIS MECHANICAL ENGINEERING TECHNOLOGY PARAMETER OPTIMIZATION IN MIG WELDING OF C20 STEEL AND SUS304 STAINLESS STEEL INSTRUCTOR: HOANG VAN HUONG STUDENT: LE MINH TUAN NGUYEN ANH TU NGYEN PHAN HONG ANH SKL013372 Ho Chi Minh City, July 2024 HO CHI MINH CITY UNIVERCITY OF TECHNOLOGY AND EDUCATION FACULTY OF MECHANICAL ENGINEERING ______________________ GRADUATION THESIS PARAMETER OPTIMIZATION IN MIG WELDING OF C20 STEEL AND SUS304 STAINLESS STEEL Supervisor: HOANG VAN HUONG Student’s name: LE MINH TUAN MSSV: 20144214 NGUYEN ANH TU MSSV: 20144213 NGUYEN PHAN HONG ANH MSSV: 19144049 Course: 2020-2024 Ho Chi Minh city, July 2024 HCMC University of Technology and Education SOCIALIST REPUBLIC OF VIETNAM FACULTY OF MECHANICAL ENGINEERING Independence-Liberty-Hapiness GRADUATION PROJECT TASKS Semester II / academic year 2024 Supervisor: Hoàng Văn Hướng Full name: Lê Minh Tuấn Student ID 20144214 Phone: 0366099493 Full name: Nguyễn Anh Tú Student ID 20144213 Phone: 0988878119 Full name: Nguyễn Phan Hồng Anh Student ID 19144049 Phone: 0977842578 1. Graduation project: - Code project:. - Project title: Parameter optimization in mig welding of C20 Steel and SUS304 stainless steel -. Initial figures and documents: …………….
Main contents of the project: ……………. Project delivery date: 6. Date of submission of the project: 7. Language of presentation: Report: English Vietnamese Protection Presentation: English Vietnamese Head of Faculty/Department SUPERVISOR (Sign and write full name) (Sign and write full name) Allowed to protect …………………………………………… (Supervisor sign, write full name) i COMMITMENT - Title Project: Parameter optimization in mig welding of C20 Steel and SUS304 stainless steel - Supervisor: Hoang Van Huong - Student’s Full name: Lê Minh Tuấn ID: 20144214 Phone: 0366099493 - Student’s address: Tang Nhon Phu A, Thu Duc city - Student’s Email: leminhtuanspkt.com - Student’s Full name: Nguyễn Anh Tu ID: 20144213 Phone: 0988878119 - Student’s address: Tan Thoi Hiep, District 12, Ho Chi Minh city - Student’s Email: tumaytinhone@gmail.com - Student’s Full name: Nguyễn Phan Hồng Anh ID: 19144049 Phone: 0977842578 - Student’s address: An Hoa, Bien Hoa city, Dong Nai province - Student’s Email: honganh7thjuly@gmail.com - Graduation thesis submission date: - Commitment: "We hereby declare that this graduation thesis is a work researched and carried out by myself.
We do not copy from any published article without citing the original source. If there is any violation, we take full responsibility. HCMC, 01/07/2024 Student ((Sign and write full name) ii ACKNOWLEDGEMENT We would like to express our heartfelt gratitude to everyone who has helped and supported us throughout our studies and the completion of this graduation project. First, we extend our sincere thanks to the Board of Directors of Ho Chi Minh City University of Technology and Education, as well as the faculty members of the Faculty of Mechanical Engineering and the Faculty of International Training, for providing us with the best learning environment and conditions.
In particular, we are deeply grateful to my supervisors- Hoang Van Huong, PhD Nguyen Van Thuc, MSc Nguyen Thanh Tan for their invaluable time in providing feedback, guidance, and support during our research process. Their dedicated guidance, instruction, and encouragement throughout the project have helped us overcome many challenges and complete this thesis. Additionally, we extend our thanks to the senior students, friends, and colleagues who have always been by our side, sharing experiences and helping us. The advice and support from everyone have been crucial to the success of this project.
Finally, we would like to express our gratitude to our families, who have continuously supported and encouraged us through all the challenges. Given our limited knowledge and experience, there are undoubtedly shortcomings in our thesis. We sincerely hope to receive feedback from our teachers and everyone else to improve our work, accumulate more knowledge, and gain experience for the future. Respectfully, Nguyen Phan Hong Anh Le Minh Tuan Nguyen Anh Tu iii ABSTRACT PARAMETER OPTIMIZATION IN MIG WELDING OF C20 STEEL AND SUS304 STAINLESS STEEL Recently, the solution of manufacturing tools and components from two different materials with the purpose of enhancing mechanical properties, durability, and reducing manufacturing costs has been receiving attention in research.
In particular, manufacturing tools and components from a pair of materials stainless steel and low carbon steel using the friction stir welding method is a promising solution currently under investigation. Some foreign research works have mentioned this solution, but the discussions are brief and mainly focus on publishing results, without detailing the calculation of welding modes and their impact on the quality of the weld joint. Additionally, most publications come from exclusive companies, closely tied to proprietary solutions and equipment, making it challenging to apply these methods in practice in Vietnam. The research topic aims to determine the welding mode to achieve a quality weld joint when welding the materials SUS 304 and C20 using the MIG welding method.
Simultaneously, experiments are conducted to optimize the welding parameters for the quality of the weld joint through the Taguchi experimental method. The weld joint quality is primarily evaluated based on tensile strength, bending strength, and observation of the microstructure of the weld joint. The optimized parameters are Current: 110A; Voltage:15mm, Stick-out:12mm, Speed:460mm/min resulting UTS of 469.37 MPa and 110A; Voltage:15mm, Stick-out:12mm, Speed:460mm/min resulting flexural strength of 1937.45 MPa for SUS304 and C20 of 2mm thickness. iv TABLE OF CONTENTS GRADUATION PROJECT TASKS.
iv TABLE OF CONTENTS .v LIST OF TABLES. viii LIST OF FIGURES. ix LIST OF ABBREVIATIONS. xi CHAPTER 1: INTRODUCTION .1 Mastering C20 welding knowledge: .2 Practicing the welding technique with 304 stainless steel .3 Analysis the result of C20 technical and compare with another welding technical .5 Objectives and scope of researching .2 Scope of researching .7 The meaning of science and practice .1 The meaning of science .2 The meaning of practice .8 The limited of this project .9 The structure of this project .4 CHAPTER 2: THEORETICAL BASIC.
Learn about mig welding technology .2 MIG welding in a protective gas environment .2 Robotic welding equipment .4 Types of metal droplet displacement in MIG welding. C20 steel material theory. Composition of the material. Characteristics of the material.
Material theory stainless steel SUS304. The composition of the material .5 General regulations in manufacturing tensile test specimens. Foundations and theory of sample testing and evaluation .1 Tensile test method. Test methods for microstructure .1 Statement of the problem about optimization .3 Design Taguchi proccess .4 Analysis of ANOVA variance .5 Concept of ANOVA .6 Steps’s analysis of variance .38 CHAPTER 3: RESEARCH, DESIGN, MANUFACTURE OF TEST SAMPLE .4 Conditions in welding sample .5 Select the parameters of MIG welding for robots .1 Refering to scientific research .2 Calculate Degree-of-freedom (DOF) rules to select an orthogonal design table .6 Designing test sample.
The size of tensile testing sample .2 The size of bending test sample: .52 CHAPTER 4: EXPERIMENTAL PROCESS .1 Experiment of tensile and bending test.2 Experiment of microstructure’s welds .57 CHAPTER 5 RESULTS AND DISCUSSION .1 Parameter optimization and analysis of varience for ultimate tensile strength .2 Parameter optimization and analysis of varience for ultimate flexural strength.4 Microstructure of welded joint .1 Geometric dimensions of welded join .2 Characteristic microstructure zones of weld materials .73 CHAPTER 6: CONCLUSION AND RECOMMENDATIONS. I Appendix 1: Images of C20 steel and SUS-304 stainless steel: microstructures and rough specimens. I Appendix 2: Images of tension and bend testing charts. XX vii LIST OF TABLES Table 2.
1 Application of shielding gas with welded metal [4]. 2 The argon of gas composition by percent mass (GOS 10157) [7]. 3 Mechanical properties of SUS304 material [19]. 4 Mechanical property for stainless steels.
5 Sample sizes follow ASTM standards [24]. 1 Sample sizes follow ASTM standards. 1 The material thickness and penetration depth. 2 The conclusion of 6 specimens have passed through out the depth of penetration.
3: Table all of 16 specimens of Taguchi and tensile test results. Response Table for Signal to Noise Ratios. 5 Analysis of variance for tensile strength. 6 Parameter optimization of UTS result.
7 Predicted values of UTS parameter optimization. 8 L16 of Taguchi and tensile test results. 9 Response Table for S/N of Flexural Strength. 10 Analysis of variance for flexural strength.
11 Parameter optimization of UTS result. 12 Predicted value of flexural strength parameter optimization. 70 viii LIST OF FIGURES Figure 2. 1 Diagram depicting the welding torch.
2 MAG welding system diagram. 3 Scheme of MIG/MAG process. 4 Diagram of electric arc welding with a molten metal electrode in a protective medium with active gas. Influence of shielding gas in Mig/Mag welding processes.
6 Two workpieces: C20 and Inox SUS 304. 7 The tank of argon gases. 8 The welding wire. 10 Structure of welding robot.
12 Argon gas pressure gauge. 15 The influence of protective gas on the weld joints and shape of the weld [14]. 17 Short circuit transformation [14]. 18 Short circuit transformation diagram [14].
21 Tensile test sample dimensions are based on ASTM E8/E8-13 standards [24]. 22 Material deformation diagram [26]. 23 Tensible testing machine. 35 No table of figures entries found.
2 The result of testing. 5 Molding the sample with AB glue. 6 Grinding the sample on sandpaper. 9 Analyzing a sample under a microscope.
1 Surface of samples. 2 L14 depicts the microstructure of a dissimilar steel weld. 3 Main effect plot for tensile strength. 4 The influence of parameters on weld quality.
5 Main effect plot for flexural strength. 6 The effect of parameters on the quality of welded joint. 69 x LIST OF ABBREVIATIONS LASER Light Amplification by Stimulated Emission of Radiation MIG Metal Inert Gas MAG Metal Active Gas OA Orthogonal Array S/N Signal-to-Noise ANOVA Analysis of Variance ATSM Automated Test Service Management SEM Scanning Electron Microscope SUS Steel Use Stainless GMAW Gas Metal Arc Welding SS Stainless Steel UTS Ultimate Tensile Strength YS Yield Strength Lf Elongation E Elastic Modulus ESO Electrical Stick – out DOP Depth of Penetration xi CHAPTER 1: INTRODUCTION 1.1 Overview Nowadays, Stainless steel and low carbon which are the two types of material are the most important and common in industrial field. Thanks to their outstanding features, they have helped them become the main material in the production of cars, ships, airplanes and unique architectural works.
Connecting different types of steel joints together to make the steel joints stronger and economical.However, this is a huge challenge for manufacturers and researchers. One of the challenges when welding two different materials is the formation of a hard and brittle intermetallic layer structure at the interface area of the two materials [1]. This intermetallic layer significantly reduces the load-bearing level of the welded joint. There have been many authors who have successfully welded carbon steel and stainless steel alloys using welding methods such as friction stir welding, laser welding, TIG welding, ultrasonic welding, etc.
The main purpose of this study is to study the welding characteristics between C20 carbon steel and SUS304 stainless steel using a semi-automatic welding process in a protective gas (MIG) environment. The results of the study focused mainly on evaluating the formation and thickness of the intermetallic layer, as well as its influence on the mechanical properties of the weld joint between these two materials.2 Domestic In Vietnam, research on the welding of different materials, especially the optimization of welding parameters to enhance the mechanical properties and durability of welded joints, has been extensively conducted. For example, Dang Thien Ngon and Tao Anh Tuan from the Ho Chi Minh City University of Technology and Education investigated the influence of welding parameters on the tensile properties of rotary friction welded joints between low carbon steel AISI 1020 and stainless steel AISI 304.