viii GMAW/FCAW Handbook Contents Chapter 1 Introduction to Gas Metal Arc Welding and Flux Cored Arc Welding . . . . . . . . . .1 GMAW and FCAW . . . . . . . . . . . . . . . . . . . . . . . 1 History. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Defi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 finitions Equipment and Modes of Operation . . . . . . . . 3 GMAW Deposition Modes . . . . . . . . . . . . . . . . . 3 FCAW Process Types . . . . . . . . . . . . . . . . . . . . . . 6 Which Process to Use? . . . . . . . . . . . . . . . . . . . . 7 Chapter 2 Welding Safety . . . . . . . . . . . . . . . . . . . .9 Welding Safety Standard . . . . . . . . . . . . . . . . . . 9 Personal Safety. . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Welding Process Safety . . . . . . . . . . . . . . . . . . . 11 Welding Environment Safety. . . . . . . . . . . . . . 14 Safety Data Sheets and Labeling of Chemicals . . 14 Chapter 3 Equipment Setup and Controls . . . . .19 Introduction to Equipment Setup . . . . . . . . . . 19 Power Sources and Specifications. . . . . . . . . . 19 fi Power Source Installation . . . . . . . . . . . . . . . . . 22 Power Source Maintenance . . . . . . . . . . . . . . . 24 Wire Feeders. . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Gun Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Welding Guns . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Workpiece Leads and Work Clamps . . . . . . . . 31 Chapter 4 Shielding Gases and Regulation Equipment . . . . . . . . . . . . . . . . . . . . . . .35 Shielding Gases . . . . . . . . . . . . . . . . . . . . . . . . . 35 Selecting the Proper Gas Mixture . . . . . . . . . . 38 Gas Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Gas Regulation. . . . . . . . . . . . . . . . . . . . . . . . . . 42 Chapter 5 GMAW and FCAW Electrodes . . . . . .45 Manufacture of GMAW and FCAW Electrodes . . .45 Electrode Specifications . . . . . . . . . . . . . . . . . . 46 fi Electrode Use . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Chapter 6 Weld Joints, Weld Types, and Welding Symbols . . . . . . . . . . . . . . . . . . . . . . . . . .53 Weld Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 Weld Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 Welding Terms and Symbols . . . . . . . . . . . . . . 58 Weld Positions . . . . . . . . . . . . . . . . . . . . . . . . . . 60 Design Considerations . . . . . . . . . . . . . . . . . . . 61 Chapter 7 Gas Metal Arc Welding Procedures and Techniques . . . . . . . . . . . . . . . . . . . . . . .69 Welding Variables and Parameters . . . . . . . . . 69 Weld Bead Patterns . . . . . . . . . . . . . . . . . . . . . . 72 Weld Schedules . . . . . . . . . . . . . . . . . . . . . . . . . 74 Chapter 8 Gas Metal Arc Welding Procedures for Carbon Steels . . . . . . . . . . . . . . . . . . . . .77 Carbon Steels . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 Electrodes for Carbon Steel . . . . . . . . . . . . . . . 78 Joint Preparation and Cleaning . . . . . . . . . . . . 80 Preheating, Interpass Temperature, and Postheating. . . . . . . . . . . . . . . . . . . . . . . . . . 80 Tooling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 Welding Procedure . . . . . . . . . . . . . . . . . . . . . . 83 Plug and Slot Welding the Carbon Steels. . . . 83 Chapter 9 Gas Metal Arc Welding Procedures for Stainless Steels . . . . . . . . . . . . . . . . . . .85 Stainless Steels . . . . . . . . . . . . . . . . . . . . . . . . . . 85 Stainless Steel Electrode Wire . . . . . . . . . . . . . 87 Joint Preparation and Cleaning . . . . . . . . . . . . 88 Tooling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 Welding Procedures . . . . . . . . . . . . . . . . . . . . . 89 Spot Welding Stainless Steels. . . . . . . . . . . . . . 91 Plug and Slot Welding Stainless Steels. . . . . . 91