Introduction to Gas Metal Arc Welding Process

Abstract

This monograph is a first-of-its-kind compilation on high deposition pulse current GMAW process. The nine chapters of this monograph may serve as a comprehensive knowledge tool to use advanced welding engineering in prospective applications. The contents of this book will prove useful to the shop floor welding engineer in handling this otherwise critical welding process with confidence. It will also serve to inspire researchers to think critically on more versatile applications of the unique nature of pulse current in GMAW process to develop cutting edge welding technology. About the Author; Nomenclature; 1 Introduction to Gas Metal Arc Welding Process; Abstract; 1.1 Behaviour of Metal Transfer; 1.2 Thermal Characteristics of GMAW Process; 1.2.1 Melting of Filler Wire; 1.2.2 Thermal Nature of Metal Transfer ; 1.3 Thermal Description of Weld; 1.3.1 Effect of Heat Flow; 1.3.2 Effect of Fluid Flow; 1.3.3 Effect of Metal Transfer ; 1.4 Weld Characteristics; 1.4.1 Weld Geometry; 1.4.2 Microstructure; 1.4.3 Weld Defects; References; 2 Concept of Pulse Current Gas Metal Arc Welding Process; Abstract; 2.1 Basic Process Variables and Control. 2.2 Phenomena of Metal Transfer2.2.1 Mechanism of Drop Detachment; 2.2.2 Nature of Metal Transfer; 2.2.2.1 One Drop Transfer Per Pulse; 2.2.2.2 Multi Drop Transfer Per Pulse; 2.2.3 Role of Pulse Parameters; 2.3 Thermal Characteristics of the Process; 2.3.1 Wire Melting; 2.3.2 Thermal Behaviour of Droplet ; References; 3 Basic Nature of Pulse Current GMA Welding; Abstract; 3.1 Governance of Pulse Characteristics; 3.2 Arc Characteristics in Welding of Different Materials; 3.2.1 Arc Profile of Pulse on Period; 3.2.1.1 Aluminium Alloy; 3.2.1.2 Stainless Steel; 3.2.1.3 Mild Steel. 3.2.2 Arc Profile of Pulse off Period3.2.2.1 Aluminium; 3.2.2.2 Stainless Steel; 3.2.2.3 Mild Steel; 3.2.3 Arc Stiffness; 3.2.3.1 Aluminium; 3.2.3.2 Stainless Steel; 3.2.3.3 Mild Steel; 3.2.4 Arc Efficiency; 3.2.4.1 Al- Mg Alloy; 3.2.4.2 Mild Steel; 3.2.4.3 Stainless Steel; 3.2.5 Arc Stability; 3.3 Shielding of Arc Environment; 3.3.1 Aluminium Alloy; 3.3.2 Stainless Steel; 3.3.3 Mild Steel; 3.3.4 Theoretical Analysis of Metal Transfer; 3.3.5 Transfer Behaviour of Different Materials; 3.3.6 Aluminium; 3.3.7 Stainless Steel; 3.3.8 Mild Steel; References. 4 Thermal Behaviour of Pulse Current Gas Metal Arc WeldAbstract; 4.1 Analytical Model of Thermal Behaviour; 4.1.1 Influence of Arc Heating; 4.1.2 Influence of Superheated Filler Metal; 4.2 Influence of Metal Transfer; 4.2.1 Cavity Formation in Weld Pool; 4.2.2 Temperature Distribution in Weld; 4.3 Thermal Nature of Welding Process; 4.4 Thermal Behaviour of Weld; 4.4.1 Temperature of Weld Pool ; 4.4.2 Temperature of HAZ; References; 5 Geometry of Pulse Current GMA Weld; Abstract; 5.1 Weld Bead on Plate Deposition; 5.1.1 Depth of Penetration; 5.1.2 Width of Weld Bead. 5.1.3 Height of Bead Reinforcement5.1.4 Area of Bead Deposit; 5.1.5 Weld Bead Toe Angle; 5.1.6 Deposition form factor; 5.1.7 Base Metal Fusion; 5.1.8 Dilution; 5.2 Non Conventional Bead on Plate Weld Deposition; 5.2.1 Weld Deposition of Flux Cored Wire; 5.2.2 Stainless Steel Cladding; 5.2.3 Out of Position Weld Deposition; 5.3 Weld Joint; 5.3.1 Flat Butt Welding; 5.3.2 Positional Welding; References; 6 Characteristics of P-GMA Weld Joint; Abstract; 6.1 Metallurgical Characteristics; 6.1.1 Chemistry of Weld; 6.1.2 Solidification of Weld Pool; 6.1.3 Porosity in Weld.