2 WELDING Principles and Applications SEVENTH EDITION Larry Jeffus Australia Brazil Japan Korea Mexico Singapore Spain United Kingdom United States
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4 Welding: Principles and Applications Seventh Edition Larry Jeffus Vice President, Editorial: Dave Garza Director of Learning Solutions: Sandy Clark Executive Editor: Dave Boelio Managing Editor: Larry Main Senior Product Manager: Sharon Chambliss Editorial Assistant: Jillian Borden Vice President, Marketing: Jennifer Baker Executive Marketing Manager: Deborah S. Yarnell Marketing Specialist: Mark Pierro Production Director: Wendy Troeger Production Manager: Mark Bernard Senior Content Project Manager: Cheri Plasse Senior Art Director: Joy Kocsis Technology Project Manager: Christopher Catalina 2012 Delmar, Cengage Learning ALL RIGHTS RESERVED. No part of this work covered by the copyright herein may be reproduced, transmitted, stored, or used in any form or by any means graphic, electronic, or mechanical, including but not limited to photocopying, recording, scanning, digitizing, taping, Web distribution, information networks, or information storage and retrieval systems, except as permitted under Section 107 or 108 of the 1976 United States Copyright Act, without the prior written permission of the publisher. For product information and technology assistance, contact us at Professional & Career Group Customer Support, For permission to use material from this text or product, submit all requests online at cengage.com/permissions Further permissions questions can be ed to Library of Congress Control Number: ISBN-13: ISBN-10: Delmar 5 Maxwell Drive Clifton Park, NY USA Cengage Learning products are represented in Canada by Nelson Education, Ltd. For your lifelong learning solutions, visit delmar.cengage.com Visit our corporate website at cengage.com Notice to the Reader Publisher does not warrant or guarantee any of the products described herein or perform any independent analysis in connection with any of the product information contained herein. Publisher does not assume, and expressly disclaims, any obligation to obtain and include information other than that provided to it by the manufacturer. The reader is expressly warned to consider and adopt all safety precautions that might be indicated by the activities described herein and to avoid all potential hazards. By following the instructions contained herein, the reader willingly assumes all risks in connection with such instructions. The publisher makes no representations or warranties of any kind, including but not limited to, the warranties of fitness for particular purpose or merchantability, nor are any such representations implied with respect to the material set forth herein, and the publisher takes no responsibility with respect to such material. The publisher shall not be liable for any special, consequential, or exemplary damages resulting, in whole or part, from the readers use of, or reliance upon, this material. Printed in the USA XX
5 This book is dedicated to two very special people my daughters Wendy and Amy.
6 Contents Preface...xii Features of the Text...xv Acknowledgments...xvii About the Author...xix Index of Experiments and Practices...xxi SECTION 1 INTRODUCTION Chapter 1 Introduction to Welding Introduction...4 Welding Defined...5 Uses of Welding...6 Welding and Cutting Processes...8 Oxyacetylene Welding, Brazing, and Cutting...10 Thermal Cutting Processes...11 Occupational Opportunities in Welding...13 Training for Welding Occupations...14 Experiments and Practices...15 Welding Video Series...17 Metric Units...17 Summary...19 Welding at the Bottom of the World...20 Review...22 Chapter 2 Safety in Welding Introduction...24 Burn Classification...24 Face, Eye, and Ear Protection...26 Respiratory Protection...28 Ventilation...31 Material Safety Data Sheets (MSDSs)...32 General Work Clothing...32 Special Protective Clothing...33 Handling and Storing Cylinders...34 Fire Protection...35 Equipment Maintenance...37 Work Area...38 Hand Tools...38 Electrical Safety...40 Electrical Safety Systems...40 Voltage Warnings...42 Extension Cords...42 Safety Rules for Portable Electric Tools...43 Metal Cutting Machines...45 Material Handling...46 Ladder Safety...47 Summary...48 Heads Up on Safety: Use Proper Head and Eye Protection...49 Review...50 SECTION 2 SHIELDED METAL ARC WELDING Chapter 3 Shielded Metal Arc Equipment, Setup, and Operation Introduction...55 Welding Current...55 Electrical Measurement...56 SMA Welding Arc Temperature and Heat...56 Types of Welding Power...57 Open Circuit Voltage...58 Operating Voltage...59 Arc Blow...59 Types of Power Sources...60 Generator- and Alternator-Type Welders...63 Converting AC to DC...65 Duty Cycle...65 Welder Accessories...66 Equipment Setup...68 Summary...69 Experienced Welders Make a Difficult Offshore Weld Run Smoothly...70 Review...71 Chapter 4 Shielded Metal Arc Welding of Plate Introduction...73 Effect of Too High or Too Low Current Settings...75 Electrode Size and Heat...76 Arc Length...77 Electrode Angle...78 Electrode Manipulation...80 Positioning of the Welder and the Plate...82 Practice Welds...82 Stringer Beads...83 Square Butt Joint...86 Edge Weld...89 iv
7 Contents v Outside Corner Joint...93 Lap Joint...96 Tee Joint...99 Summary Keeping Shipshape through Underwater Welding Review Chapter 5 Shielded Metal Arc Welding of Pipe Introduction Pipe and Tubing Preparation and Fit-Up Practice Welds G Horizontal Rolled Position G Vertical Fixed Position G Horizontal Fixed Position G 45 Inclined Position Summary Orbital Welding Helps NASA s X-34 Rocket Soar Review Chapter 6 Advanced Shielded Metal Arc Welding Introduction Root Pass Hot Pass Filler Pass Cover Pass Plate Preparation Preparing Specimens for Testing Restarting a Weld Bead Preheating and Postheating Poor Fit-Up Summary Artists Honored at International Institute of Welding (IIW) Assembly Review SECTION 3 CUTTING AND GOUGING Chapter 7 Flame Cutting Introduction Metals Cut by the Oxyfuel Process Eye Protection for Flame Cutting Cutting Torches Cutting Tips Oxyfuel Cutting, Setup, and Operation Hand Cutting Layout Selecting the Correct Tip and Setting the Pressure The Chemistry of a Cut The Physics of a Cut Plate Cutting Cutting Table Torch Guides Distortion Cutting Applications Pipe Cutting Summary Oxygen Cutting Review Chapter 8 Plasma Arc Cutting Introduction Plasma Plasma Torch Power and Gas Cables Power Requirements Compressed Air Heat Input Distortion Applications Machine Cutting Manual Cutting Safety Straight Cuts Plasma Arc Gouging Cutting Round Stock Summary Weld Shop Keeps U.S. Coast Guard Ready Review Chapter 9 Related Cutting Processes Introduction Laser Beam Cutting (LBC) and Laser Beam Drilling (LBD) Lasers Applications Air Carbon Arc Cutting Manual Torch Design Application Safety U-Grooves Oxygen Lance Cutting Applications Safety Water Jet Cutting Applications Arc Cutting Electrodes Applications Summary Lasers: The New Wave in Ship Construction Review...231
8 vi Contents SECTION 4 GAS SHIELDED WELDING Chapter 10 Gas Metal Arc Welding Equipment, Setup, and Operation Introduction Weld Metal Transfer Methods Short-Circuiting Transfer GMAW-S Globular Transfer Axial Spray Metal Transfer Pulsed-Arc Metal Transfer Pulsed-Arc Metal Transfer Current Cycle Shielding Gases for Spray or Pulsed-Spray Transfer Buried-Arc Transfer GMAW Filler Metal Specifications Wire Melting and Deposition Rates Welding Power Supplies Speed of the Wire Electrode Power Supplies for Short-Circuiting Transfer Molten Weld Pool Control Power Settings Weave Pattern Travel Speed Electrode Extension Gun Angle Equipment Power Source Electrode (Wire) Feed Unit GMA Spot Welding Summary Simple Steps to Achieving Better Gas Metal Arc Welding Review Chapter 11 Gas Metal Arc Welding Introduction Setup Gas Density and Flow Rates Wire-Feed Speed Arc-Voltage and Amperage Characteristics Electrode Extension Welding Gun Angle Effect of Shielding Gas on Welding Practices Metal Preparation Flat Position, 1G and 1F Positions Vertical Up 3G and 3F Positions Vertical Down 3G and 3F Positions Horizontal 2G and 2F Positions Overhead 4G and 4F Positions Globular Metal Transfer, 1G Position Axial Spray Summary Aluminum Ferries Rely on Inverter Technology Review Chapter 12 Flux Cored Arc Welding Equipment, Setup, and Operation Introduction Principles of Operation Equipment Advantages Limitations FCAW Electrodes FCA Welding Electrode Flux Shielding Gas Welding Techniques Troubleshooting FCA Welding Summary Ultrasonic Plastic Welding Basics Review Chapter 13 Flux Cored Arc Welding Introduction Practices Flat-Position Welds Square-Groove Welds V-Groove and Bevel-Groove Welds Fillet Welds Vertical Welds Horizontal Welds Overhead-Position Welds Thin-Gauge Welding Plug Welds Summary Welding Lends Architectural Flair to Airport Expansion Review Chapter 14 Other Constant-Potential Welding Processes Introduction Submerged Arc Welding (SAW) Weld Travel Electrode Feed Contact Tip Electrode Flux Advantages of SAW Disadvantages of SAW Arc Starting Weld Backing Handheld SAW Experiments Electroslag Welding (ESW) Electrogas Welding (EGW)...369
9 Contents vii Summary High-Performance Steel Increasingly Used for Bridge Building Review Chapter 15 Gas Tungsten Arc Welding Equipment, Setup, Operation, and Filler Metals Introduction Tungsten Types of Tungsten Electrodes Shaping the Tungsten GTA Welding Equipment Types of Welding Current Shielding Gases Preflow and Postflow Shielding Gas Flow Rate Remote Controls Summary Welding a Pathway to the Stars Review Chapter 16 Gas Tungsten Arc Welding of Plate Introduction Torch Angle Filler Rod Manipulation Tungsten Contamination Current Setting Experiments Gas Flow Practice Welds Summary The Great Master s Horse Returns Home after 500 Years Review Chapter 17 Gas Tungsten Arc Welding of Pipe Introduction Practices Joint Preparation Root Backing Gas Filler Metal Cup Walking Practice Welds Hot Pass Filler Pass Cover Pass Summary Hot Tap Weld Prevents Offshore Piping System from Shutting Down Review SECTION 5 RELATED PROCESSES Chapter 18 Shop Math and Weld Cost Introduction Shop Math Types of Numbers General Math Rules Equations and Formulas Mixed Units Adding and Subtracting Mixed Units Fractions Finding the Fraction s Common Denominator Reducing Fractions Multiplying and Dividing Fractions Converting Numbers Converting Fractions to Decimals Converting Decimals to Fractions Conversion Charts Measuring Welding Costs Cost Estimation Joint Design Weld Metal Cost Cost of Electrodes, Wires, Gases, and Flux Deposition Efficiency Deposition Rate Deposition Data Tables Operating Factor Other Useful Formulas Summary Metal Cored Welding Wire Comes through on Heavy Weldments Review Chapter 19 Reading Technical Drawings Introduction Mechanical Drawings Lines Types of Drawings Special Views Dimensioning Drawing Scale Reading Mechanical Drawings Sketching Erasers and Erasing Graph Paper Computers and Drawings Summary Resistance Seam Welding Benefits Stainless Application Review...500
10 viii Contents Chapter 20 Welding Joint Design and Welding Symbols Introduction Weld Joint Design Welding Process Edge Preparation Joint Dimensions Metal Thickness Metal Type Welding Position Code or Standards Requirements Welder Skill Acceptable Cost Welding Symbols Indicating Types of Welds Weld Location Location Significance of Arrow Fillet Welds Plug Welds Spot Welds Seam Welds Groove Welds Backing Flanged Welds Nondestructive Testing Symbols Summary Extending the Life of Resistance Welding Electrodes Review Chapter 21 Fabricating Techniques and Practices Introduction Fabrication Safety Parts and Pieces Layout Nesting Kerf Space Material Shapes Bill of Materials Form Overall Tolerance Assembly Assembly Tools Fitting Tack Welds Welding Finishing Summary Welder Certification: Many Thrusts, Few Agree Review Chapter 22 Welding Codes and Standards Introduction Codes, Standards, Procedures, and Specifications Welding Procedure Qualification Welding Procedure Specification (WPS) Qualifying the Welding Procedure Specification Qualifying and Certifying General Information Summary Resistance Seam Welding Benefits Stainless Steel Application Review Chapter 23 Testing and Inspection of Welds Introduction Quality Control (QC) Discontinuities and Defects Porosity Inclusions Inadequate Joint Penetration Incomplete Fusion Arc Strikes Overlap Undercut Crater Cracks Underfill Plate-Generated Problems Lamination Delamination Lamellar Tears Destructive Testing (DT) Tensile Testing Fatigue Testing Shearing Strength of Welds Welded Butt Joints Fillet Weld Break Test Testing by Etching Impact Testing Nondestructive Testing (NDT) Visual Inspection (VT) Penetrant Inspection (PT) Magnetic Particle Inspection (MT) Radiographic Inspection (RT) Ultrasonic Inspection (UT) Leak Checking Eddy Current Inspection (ET) Hardness Testing Summary Development of Titanium Inspection Tools Based on Weld Color Review Chapter 24 Welder Certification Introduction Qualified and Certified Welders Welder Performance Qualification Welder Certification AWS Entry-Level Welder Qualification and Welder Certification...597
11 Contents ix Practical Knowledge Welder Qualification and Certification Test Instructions for Practices Preparing Specimens for Testing Restarting a Weld Bead Summary Liberty Ships of World War II Review SECTION 6 RELATED PROCESSES AND TECHNOLOGY Chapter 25 Welding Metallurgy Introduction Heat, Temperature, and Energy Heat Temperature Mechanical Properties of Metal Hardness Brittleness Ductility Toughness Strength Other Mechanical Concepts Structure of Matter Crystalline Structures of Metal Phase Diagrams Lead-Tin Phase Diagram Iron-Carbon Phase Diagram Strengthening Mechanisms Solid-Solution Hardening Precipitation Hardening Mechanical Mixtures of Phases Quench, Temper, and Anneal Martensitic Reactions Cold Work Grain Size Control Heat Treatments Associated with Welding Preheat Stress Relief, Process Annealing Annealing Normalizing Thermal Effects Caused by Arc Welding Gases in Welding Hydrogen Nitrogen Oxygen Carbon Dioxide Metallurgical Defects Cold Cracking Hot Cracking Carbide Precipitation Summary Shot Peening and Heat Treatment Reduce Stress Review Chapter 26 Weldability of Metals Introduction Steel Classification and Identification SAE and AISI Classification Systems Unified Numbering System (UNS) Carbon and Alloy Steels Low Carbon Also Called Mild Steel Medium Carbon Steel High Carbon Steel Tool Steel High Manganese Steel Low Alloy, High Tensile Strength Steels Stainless Steels Chromium-Molybdenum Steel Cast Iron Practice Welding Cast Iron Nonferrous Metals Copper and Copper Alloys Aluminum Weldability Titanium Magnesium Repair Welding Summary Welding Offers Answers about New Chrome-Moly Steel Review Chapter 27 Filler Metal Selection Introduction Manufacturers Electrode Information Understanding the Electrode Data Data Resulting from Mechanical Tests Data Resulting from Chemical Analysis Carbon Equivalent (CE) SMAW Operating Information Core Wire Functions of the Flux Covering Filler Metal Selection Shielded Metal Arc Welding Electrode Selection AWS Filler Metal Classifications Carbon Steel Carbon and Low Alloy Steel Covered Electrodes Wire-Type Steel Filler Metals Solid Wire Tubular Wire Stainless Steel Electrodes Nonferrous Electrodes Aluminum and Aluminum Alloys Aluminum-Covered Arc Welding Electrodes Aluminum Bare Welding Rods and Electrodes Special-purpose Filler Metals...704
12 x Contents Surface and Buildup Electrode Classification Magnesium Alloys Hydrogen Embrittlement Summary Filler Metal Made Easy Review Chapter 28 Welding Automation and Robotics Introduction Manual Joining Process Semiautomatic Joining Processes Machine Joining Processes Automatic Joining Processes Automated Joining Industrial Robots Robot Programming System Planning Future Automation Summary Improving Productivity with Robotic Welding Review Chapter 29 Other Welding Processes Introduction Resistance Welding (RW) Resistance Spot Welding (RSW) Seam Welding (RSEW) High-Frequency Resistance Seam Welding (RSEW-HF) Resistance Projection Welding (RPW) Flash Welding (FW) Upset Welding (UW) Percussion Welding (PEW) Electron Beam Welding (EBW) Electron Beam Welding Gun Electron Beam Seam Tracking Ultrasonic Welding (USW) Ultrasonic Welding Applications Inertia Welding Process Inertia Weld Bond Characteristics Advantages of the Process Laser Beam Welding (LBW) Laser Welding Advantages and Disadvantages Laser Beam Plasma Arc Welding (PAW) Process Stud Welding (SW) Thermal Spraying (THSP) Thermal Spraying Equipment Thermospray (Powder) Process Plasma Spraying Process Cold Welding (CW) Thermite Welding (TW) Hardfacing Selection of Hardfacing Metals Hardfacing Welding Processes Quality of Surfacing Deposit Hardfacing Electrodes Shielded Metal Arc Method Hardfacing with Gas Shielded Arc Carbon Arc Method Summary Computer Numeric Controlled Plasma A Cut above the Rest Review SECTION 7 OXYFUEL Chapter 30 Oxyfuel Welding and Cutting Equipment, Setup, and Operation Introduction Pressure Regulators Regulator Operation Regulator Gauges Regulator Safety Pressure Release Device Cylinder and Regulator Fittings Regulator Safety Precautions Regulator Care and Use Welding and Cutting Torches: Design and Service Mixing the Gases Torch Care and Use Welding and Heating Torch Tips Torch Tip Care and Use Backfires Flashbacks Reverse Flow and Flashback Valves Care of the Reverse Flow Valve and Flashback Arrestor Hoses and Fittings Hose Care and Use Types of Flames Leak Detection Manifold Systems Manifold Operation Summary Worcester Technical High School Welds on Snowflakes Review Chapter 31 Oxyfuel Gases and Filler Metals Introduction Oxyfuel Flame Characteristics of the Fuel-Gas Flame Fuel Gases Flame Rate of Burning Acetylene (C 2 H 2 ) Liquefied Fuel Gases Methylacetylene-Propadiene (MPS) MAPP...790
13 Contents xi Propane and Natural Gas Hydrogen Filler Metals Ferrous Metals Mild Steel Cast Iron Summary Welding with the Right Shielding Gas Review Chapter 32 Oxyacetylene Welding Introduction Mild Steel Welds Factors Affecting the Weld Characteristics of the Weld Flat Position Welding Outside Corner Joint Butt Joint Lap Joint Tee Joint Out-of-Position Welding Vertical Welds Butt Joint Lap Joint Tee Joint Horizontal Welds Horizontal Stringer Bead Butt Joint Lap Joint Tee Joint Overhead Welds Stringer Bead Mild Steel Pipe and Tubing Horizontal Rolled Position 1G Horizontal Fixed Position 5G Vertical Fixed Position 2G Fixed Position 6G Thin-Wall Tubing Summary Confined Space Monitors: Tough Choices for Tight Spots Review Chapter 33 Soldering, Brazing, and Braze Welding Introduction Advantages of Soldering and Brazing Physical Properties of the Joint Shear Strength Ductility Fatigue Resistance Corrosion Resistance Fluxes Flux Fluxing Action Soldering and Brazing Methods Method Grouping Torch Soldering and Brazing Furnace Soldering and Brazing Induction Soldering and Brazing Dip Soldering and Brazing Resistance Soldering and Brazing Special Methods Filler Metals Types of Filler Metals Soldering Alloys Brazing Alloys Joint Design Joint Spacing Brazing Practices Surface Buildup and Hole Fill Practices Silver Brazing Pracitces Soldering Practices Summary Greater Lowell Tech Welding Students Restore Historic Statue Review Appendix I. Student Welding Report II. Conversion of Decimal Inches to Millimeters and Fractional Inches to Decimal Inches and Millimeters III. Conversion Factors: U.S. Customary (Standard) Units and Metric Units (SI) IV. Abbreviations and Symbols V. Metric Conversion Approximations VI. Pressure Conversion VII. Welding Codes and Specifications VIII. Welding Associations and Organizations Glossary Index...925
14 Preface Introduction The welding industry presents a continuously growing and changing series of opportunities for skilled welders. Even with economic fluctuations, the job outlook for skilled welders is positive. Due to a steady growth in the demand for goods fabricated by welding, new welders are needed in every area of welding such as small shops, specialty fabrication shops, large industries, and construction. The student who is preparing for a career in welding will need to have excellent eye hand coordination. work well with tools and equipment. know the theory and application of the various welding and cutting processes. be able to follow written and verbal instructions. work with or without close supervision. have effective written and verbal communications skills. be able to resolve basic mathematical problems. work well individually and in groups. read and interpret welding drawings and sketches. be computer literate. be alert and work safely. A thorough study of Welding: Principles and Applications in a classroom/shop setting will help students prepare for the opportunities in welding technology. The comprehensive technical content provides the basis for the welding processes. The extensive descriptions of equipment and supplies, with in-depth explanations of their operation and function, are designed to familiarize students with the tools of the trade. The process descriptions, practices, and experiments coupled with actual performance teach the critical fabrication and welding skills required on the job. The text also discusses occupational opportunities in welding and explains the training required for certain welding occupations. The skills and personal traits recommended by the (AWS) for its Certified Welder program are included within the text. Students wishing to become certified under the AWS program must contact the for specific details. The National Center for Welding Education and Training, known as Weld-Ed, is a partnership between business and industry, community and technical colleges, universities, the, and government to promote welding education. Organization The text is organized to guide the student s learning from an introduction to welding, through critical safety information, to details of specific welding and cutting processes, and on to the related areas of shop math, welding metallurgy, weldability of metals, reading technical drawings, fabrication, certification, testing and inspection of welds, and welding joint design, costs, and welding symbols. Each section of the text introducing a welding process or processes begins with an introduction to the equipment and materials to be used in the process(es), including xii
15 Preface xiii setup in preparation for welding. The remaining chapters for the specific process concentrate on the actual welding techniques in various applications and positions. The content progresses from basic concepts to the more complex welding technology. Once this technology is understood, the student is able to quickly master new welding tasks or processes. The sections on welding processes are laid out so that they can be studied individually and in any order. This was done so students can study the process or processes that might relate to their job requirements. However, students are encouraged to study and learn all of the processes so they have the broadest possible future job opportunities. Objectives listed at the beginning of each chapter tell the student and instructor what is to be learned while studying the chapter. A survey of the objectives will show that the student will have the opportunity to develop a full range of welding skills. Each major process is presented independently so that the instructor can include or exclude them to better meet the needs of the local area served by the program. However, the student can still learn all essential information needed for a thorough understanding of all processes studied. Key Terms are listed at the beginning of the chapter. These key terms are boldfaced and defined throughout the chapters so students will recognize them as they appear. Terms and definitions used throughout the text are based on the s standards. Industry jargon has also been included when appropriate. Cautions for the student are given throughout the text and point out potential safety concerns or give additional specific information that will make working safer. Think Green text boxes contain information on both conserving materials, energy, and other natural resources and ways to avoid potential environmental contamination. Metric equivalents are listed in parentheses for dimensions. When the standard unit is an approximation, the metric equivalent has been rounded to the nearest whole number; however, when the standard unit is an exact value, the metric conversions are more precise. Illustrations consist of figures, tables, and charts. Figures include both photographs and line art. Numerous figures contain close-up full-color photos of actual welding, and others show welding products and equipment. The colorful detailed figure line art is used extensively throughout the text to help illustrate concepts and clarify the material. Tables and charts contain valuable technical information on materials, equipment setup, and welding process parameters. They are designed to help the student in class and serve later as an on-the-job reference. Experiments and Practices are learning activities that are presented in most of the chapters. The end of each experiment is identified by the ( ) symbol and the end of each practice is identified by the ( ) symbol. Experiments help the student learn the parameters of each welding process. Often, because it is hard both to perform the experiment and to observe the results closely, students may do most of the experiments in a small group. In the experiments, students change the parameters to observe the effect on the process. In this way, students learn to manipulate the variables to obtain the desired welding outcome for given conditions. The experiments provided in the chapters do not have right or wrong answers. They are designed to allow the student to learn the operating limitations or the effects of changes that may occur during the welding process. Practices are included to enable the student to develop the required manipulative skills, using different materials and material thicknesses in different positions for each process. A sufficient number of practices is provided so that, after the basics are learned, the student may choose an area of specialization. Materials specified in the practices may be varied in both thickness and length to accommodate those supplies that students have in their lab. Changes within a limited range of both thickness and length will not affect the learning process designed for the practice. Mechanical drawings are included with many of the welding practices. These drawings are included to help students better understand mechanical drawings and to show them how the metal is assembled. Most of the drawings are laid out in third-angle projection format, some are in the first-angle projection format, and a few are laid out with the side view shown in an alternate position. The third-angle projection format has been the standard used in the United States for years. However, because of the increasing interaction with the world economy and the fact that many other countries use the first-angle projection format, it has been included. All three drawing formats are commonly used and are included. Items not normally included on true mechanical drawings such as the weld, torch or electrode, and filler metal have been included to aid in students understanding of the drawings. Summaries at the end of each chapter recap the significant material covered in the chapter. This summary will help the student more completely understand the chapter material and will serve as a handy study tool. Review questions at the end of each chapter can be used as indicators of how well the student has learned the material in each chapter. Glossary definitions include the key terms listed at the beginning of each chapter and also other relevant welding terms. Included in the Glossary are bilingual terms in Spanish. Many definitions feature additional drawings to assist students in gaining a complete understanding of the terms. Computers in Welding As in every skilled trade in today s ever-changing world, computers are commonly used in welding. Some of the basic programs provide a cross-reference to welding filler metals, whereas others aid in weld symbol selection.
16 xiv Preface More complex programs allow welding engineers to design structures and test them for strength without ever building them. These programs aid in proper design and make more effective use of materials, resulting in better, more cost-effective construction. Some programs are helpful in writing Welding Procedure Specifications (WPSs), Procedure Qualification Records (PQRs), and Welder Qualification Test Records (WQTRs). These three types of documents are extensively used throughout the welding industry. Most of the welding programs operate on a variety of platforms, but the most popular ones use a version of Microsoft Windows. Having a good basic understanding of the Windows operating platform will give you a great start with these programs. In addition, you should become familiar with one of the commonly used word processing programs, such as Microsoft Word. This will aid you in producing high-quality reports both in school and later on the job. This seventh edition of Welding: Principles and Applications has been thoroughly revised and reorganized to reflect the latest welding technologies. Changes include the following: New chapters include Shop Math and Weld Cost, Reading Technical Drawings, and Fabricating Techniques and Practices Think Green boxed articles on environmental and conservation welding topics New welding processes and technologies such as friction stir welding Expanded material on processes such as plasma cutting, FCAW, GMAW, and others New Success Story vignettes from students, instructors, and welders telling their stories about learning to weld, jobs they have done, and other real-world experiences New feature stories at the end in many of the chapters New and updated illustrations and photographs in every chapter The use of new, full-color, detailed close-up photographs and detailed colored line art make it much easier for the student to see what is expected to produce a quality weld. Supplements Accompanying the text is a carefully prepared supplements package, which includes an Instructor s Guide, an Instructor s e-resource, a Study Guide/Lab Manual, CourseMate, WebTutor Advantage, and the Welding Principles and Practices on DVD series. The seventh edition Instructor Resources CD includes an instructor s guide in Microsoft Word, a computerized test bank in ExamView with hundreds of modifiable questions, chapter presentations in PowerPoint with fullcolor images and video clips, and a searchable Image Library of hundreds of full-color photos and line art from the core text. The Study Guide/Lab Manual (ISBN: ) has been updated to reflect changes made to the seventh edition. The Study Guide/Lab Manual is designed to reinforce student understanding of the concepts presented in the text. Each chapter starts with a review of the important topics discussed in the chapter. Students can then test their knowledge by answering additional questions. Lab exercises are included in those chapters (as appropriate) to reinforce the primary objectives of the lesson. Artwork and safety precautions are included throughout the manual. The Welding Principles and Practices on DVD series explains the concepts and shows the procedures students need to understand to become proficient and professional welders. In-text references are provided for selected videos from the DVD series. Delmar Cengage Learning s Welding Principles and Practices on DVD combines previously released welding videos with new footage and revisions to bring the material completely up to date. Four DVDs cover shielded metal arc welding, gas metal arc welding, flux cored arc welding, and oxyacetylene welding in detail. The main subject areas are further broken down into subsections on each DVD for easy comprehension. This DVD set offers instructors and students the best welding multimedia learning tool at their fingertips. The CourseMate for the seventh edition of Welding: Principles and Applications offers students and instructors access to important tools and resources, all in one online environment. The CourseMate includes an interactive e-book for Welding: Principles and Applications, Seventh Edition; video clips; interactive quizzes; flashcards; an interactive glossary; and an Engagement Tracker tool for monitoring student progress in the CourseMate product. Newly available for Welding: Principles and Applications is WebTutor Advantage for the Blackboard online course management system. The WebTutor includes chapter presentations in PowerPoint, end-of-chapter review questions, tests, discussion springboard topics, and more, all designed to enhance the classroom and shop experience.
17 Features of the Text FEATURES OF THE TEXT xv OBJECTIVES Chapter 14 Other Constant-Potential Welding Processes After completing this chapter, the student should be able to describe the various types of SAW fluxes. explain how the SAW process works. explain how the ESW and EGW processes work. name the parts of a SAW setup. list the methods of starting the SAW arc. list the major advantages and limitations of the SAW, ESW, and EGW processes. KEY TERMS arc starting bonded fluxes electrogas welding (EGW) electroslag welding (ESW) fused fluxes granular fluxing mechanically mixed fluxes strip electrodes submerged arc welding (SAW) twisted wire water-cooled dams Objectives, found at the beginning of each chapter, are a brief list of the most important topics to study in the chapter. Key Terms are the most important technical words you will learn in the chapter. These are listed at the beginning of each chapter following the Objectives and appear in color print where they are first defined. These terms are also defined in the Glossary at the end of the book. The Welding: Principles and Practices on DVD series, explains the concepts and shows the procedures students need to understand to become proficient and professional welders. Four DVDs cover shielded metal arc welding, gas metal arc welding, flux cored arc welding, and oxyacetylene welding in detail. Cautions summarize critical safety rules. They alert you to operations that could hurt you or someone else. Not only are they covered in the safety chapter, but you will find them throughout the text when they apply to the discussion, practice, or experiment. INTRODUCTION In addition to GMAW and FCAW there are three other continuous feed electrode processes. As with GMAW and FCAW, a constant-potential (CP) power supply provides the welding current. These processes are submerged arc welding (SAW), electroslag welding (ESW), and electrogas welding (EGW). Each of these three processes provides the welding industry with significant specialized benefits. SAW, ESW, and EGW can be considered the workhorses of the fabrication industry. These processes are used to fabricate large, thick sections. They can weld metal ranging from 3/8 in. (10 mm) to more than 20 in. (508 mm) thick in a single operation, depending on the process selected. They are also used to cover large areas on tanks and pressure vessels with welded coverings of special alloys. This allows the unit to be fabricated out of a less expensive metal but have the surface of the expensive alloy. The total cost of the fabrication is less, yet it will provide the same or better service Section 7 Oxyfuel flame has an excess of oxygen. This flame has the highest temperature and may put oxides in the weld metal. LEAK DETECTION A leak-detecting solution can be purchased premixed and ready to use or as a concentrate that must be mixed with water. It can also be mixed in the shop by using a small quantity of liquid dishwashing detergent in water. Use only enough detergent to produce bubbles; too much detergent will leave a soapy film. A leak-detecting solution must be free flowing so that it can seep into small joints, cracks, and other areas that may have a leak. The solution must produce a good quantity of bubbles without leaving a film. The solution can be dipped, sprayed, or brushed on the joints. Chapter 31 Oxyfuel Gases and Filler Metals 793 THINK GREEN Nonpolluting Fuel-Gas Flame The oxygen and hydrogen flame is the only 100% nonpolluting fuel-gas flame. The only by-product from this flame is water vapor. In addition, both oxygen and hydrogen gases can be produced with electrolysis of water by using renewable energy such as solar or wind. EXPERIMENT 31-2 Oxyfuel Flames Using an identical torch set with each available fuel gas, you are going to observe the flame as each fuel gas is ACETYLENE MAPP safely lit, adjusted, and extinguished. Set all fuel and oxygen regulators at approximately FIGURE psig (35 kpag). Each torch should have the same-size The second fuel-gas flame may be slightly off the tip. Cengage Learning 2012 tip. The tip should have an orifice equal to a number 53 to 60 drill. Place the torches on a table with the tips pointed up, Figure Starting with the oxyacetylene torch, turn on the fuelgas valve slightly. Using a flint lighter, light the torch and move them just as you did with the acetylene torch. The One at a time, pick up each of the other torches and adjust the gas valve so that the flame is not smoking. flames on these torches will deflect more, and some After securely placing the lit torch back on the table, flames may go out, Figure 31-22B. The reason for the difference is that less gas is flowing with each of the other repeat the process with all of the other torches. Adjust the flame of each torch to the same size as the acetylene gases. The acetylene flame is more stable because it has flame, Figure the highest flow rate and the highest burn rate. Thus, the Pick up the acetylene torch and move it back and forth, flame is more compact. Figure 31-22A. The flame should be stable, with only the Turn on the oxygen valve slowly until the acetylene top deflecting as the torch is moved. Replace the torch flame is adjusted to a neutral setting. Repeat this procedure with each of the other flames. The flames may carefully on the table. blow ///CAUTION\\\ Some detergents are not suitable for O 2 because of an oil base. Use only O 2-approved leak-detection solutions on oxygen fittings. PRACTICE 30-1 Setting Up an Oxyfuel Torch Set This practice requires a disassembled oxyfuel torch set consisting of two regulators, two reverse flow valves, one set of hoses, a torch body, a welding tip, two cylinders, a portable cart or supporting wall, and a wrench. You will assemble the equipment in a safe manner. 1. Safety chain the cylinders separately to the cart or to a wall, Figure Then remove the valve protection caps, Figure Crack the cylinder valve on each cylinder for a second to blow away dirt that may be in the valve, Figure FIGURE Safety chain cylinder. Larry Jeffus. See DVD Oxyacetylene Welding. FIGURE Unscrew the valve protector caps. Put the caps in a safe place as they must be replaced on empty cylinders before they are returned. Larry Jeffus. See DVD Oxyacetylene Welding. FIGURE Cracking the oxygen and fuel cylinder valves to blow out any dirt lodged in the valves. Larry Jeffus. See DVD Oxyacetylene Welding. ///CAUTION\\\ If a fuel-gas cylinder does not have a valve hand wheel permanently attached, you must use a nonadjustable wrench to open the cylinder valve. The wrench must stay with the cylinder as long as the cylinder is on, Figure NOTE: TORCH TIPS POINTING UPWARD Think Green boxes contain information on both conserving materials, energy, and other natural resources and ways to avoid potential environmental contamination. FIREBRICK TABLETOP Practices are hands-on exercises designed to build your welding skills. Each practice describes in detail what skill you will learn and what equipment, supplies, and tools you will need to complete the exercise. FIGURE Torches set up to compare fuel gases. Cengage Learning 2012 Experiments are designed to allow you to see what effect changes in the process settings, operation, or techniques have on the type of weld produced. Many are group activities and will help you learn as a team.
18 xvi Features of the Text 370 Section 4 Gas Shielded Welding Summaries review the important points in the chapter and serve as a useful study tool. Real-World Features at the end of all chapters present a story that describes a real-world application of the theory learned in the chapter. You will see how particular knowledge and skills are important to the world. Summary Submerged arc welding, electroslag welding, and Because of the high amperages and large molten electrogas welding processes are most often used for weld pools with these processes, it is not practical in automated high-volume manufacturing facilities. These most cases for welders to attempt these as manual processes are used in the production of large welds in processes. Therefore, most of the time these are produced using an automated machine, or robotic weld- massive weldments. They are an ideal selection for rapidly producing such large, high-quality welds. ing station. Manual SMAW is covered in this chapter so students who do not have access to the automated equipment can experiment with the process. 372 Section 4 Gas Shielded Welding flux should be put in use or immediately transferred Currently, both gas metal arc welding and flux cored arc to the holding oven. welding consumables are being developed and tested to Flux handling. Eventually, flux particles will break determine if these processes are suitable for use on HPS down into fines (or dust). Flux recovery equipment 70W. Second, fabricators of bridge girders are evolving and cannot always separate out the fines, so operators becoming more sophisticated in methods for preheating should regularly purge the flux recovery equipment and maintaining interpass temperature, improved flux handling procedures, and trying alternate welding processes. of all flux in the system and replace it with new flux. Operators should also take every precaution to ensure Third, use of high-technology fabrication equipment, such moisture does not contaminate flux during the welding process. tive designs. as robotics, is being examined for the fabrication of innova- Since fabricating HPS 70W is relatively easy when the right consumables, process, and procedures are combined, Future of HPS more HPS 70W bridge projects are expected to be started. Now that HPS 70W use is growing in the industry, what Article courtesy of the Tennessee Department of Transportation. is next for the new steel? Review 1. What protects the molten SAW pool from the 11. What must be done with SA fluxes to prevent atmosphere? contamination of the weld by hydrogen? 2. How can manual SA welding gun movement be 12. Why does the welder not have to wear a welding performed? helmet? 3. What are the two methods of mechanical travel 13. What happens to the unfused SA welding flux? for SA welding? 14. Why is some form of mechanical guidance required 4. How is the weld metal deposited in the molten with SA welding? weld pool of the SA welding process? 15. List the common methods used to start the SA arc. 5. In what forms can SA welding filler metal be 16. Why would handheld SA welding be used? purchased? 17. What special characteristics must ES welding 6. How is the manganese range of the SA electrode slags have? noted in the AWS classification? 18. What heats the ES welding flux? 7. Why could a single SA welding flux have more than one AWS classification? 19. How is an ES weld started? 8. List the three groupings of SA welding fluxes 20. Why do ES welds have large grain sizes? according to their method of manufacturing. 21. List the advantages of ES welding. 9. Why are alloys not added to fused SA fluxes? 22. What is the major difference between ESW 10. What is in bonded SA fluxes? and EGW? High-Performance Steel Increasingly Used for Bridge Building HPS 70W, a relatively new material for bridge construction, has many advantages, including corrosion and cracking resistance, high strength, and improved toughness characteristics. The number of states using high-performance steel (HPS) 70W for bridge construction has steadily increased over the past several years. This is largely due to a law signed in 1988, the Transportation Equity Act for the 21st Century (TEA-21), which authorizes highway and other surface transportation programs for the next six years. Under TEA-21, states receive federal funds to improve highways, opening the door to many new construction projects across the United States. To encourage use of this new metal, the act provides additional funds for bridge projects constructed with HPS 70W. The Evolution of HPS 70W for Bridge Construction The military originally developed high-performance steel for use in submarine construction. In 1994, Congress established a steering committee composed of the U.S. Navy, the Federal Highway Administration (FHWA), and the American Iron and Steel Institute (AISI) to research ways HPS could be transferred from military technology to civilian applications. In particular, the committee was charged with finding new ways to use the steel for bridge construction. HPS 70W (70,000 lb/in. 2 yield strength steel) was considered for bridge work because it offers the industry many advantages. First and foremost, it has outstanding corrosion-resistance properties. The W in HPS 70W stands for weathering and means this material has controlled rusting characteristics that allow just enough corrosion to occur so a rust barrier is formed. Because of this barrier, painting is not required, meaning less maintenance for state highway crews. In contrast, a nonweathering steel often used in bridge construction requires constant painting and maintenance. The 995-ft-long Clear Fork River Bridge in Tennesse was built with HPS 70W steel. Tennessee Department of Transportation Review questions help measure the skills and knowledge you learned in the chapter. Each question is designed to help you apply and understand the information in the chapter. Success Stories are found at the beginning of each of the seven sections in the text. These stories are about real people who have become successful by using their welding skills. Each story is different, but one message is repeated by all story contributors: welding can be a rich and rewarding career. Bilingual Glossary definitions provide a Spanish equivalent for each new term. Additional line art in the Glossary will also help you gain a greater understanding of challenging terms. Success Story Rieke, who now lives in La Junta, Colorado, Kassandra started her welding career at an early age. She was just 12 years old when her uncle first taught her to weld on a ranch in Meeker, Colorado. Never afraid of hard work, she got a job when she was just 18 years old running heavy equipment at a big gravel pit in Meeker for about a year. Just after her 19th birthday, a friend took her to work as a welder s helper on oil and gas rigs. Welding on oil rigs can be a lot of hard work we usually worked six twelves (12 hours a day 6 days a week), but when you love what you are doing, it does not feel like work. She fondly recalls working 38 straight hours to get one rig back in service. When one of the rigs is down, you just have to keep on welding as long as it takes to get it back working. Even with the long hours, she was back welding, a job she loved, and this was the beginning of her career. By the time she moved with her family to Pueblo, she had graduated from high school and was looking for a welding school to hone her skills. She wanted to learn more about natural gas pipe welding. After visiting several schools and having heard some great things about it from welder friends, she decided to attend Trinidad State Junior College s Energy Production Industrial Construction Program. As an outdoor enthusiast who loves hunting, fishing, and working outdoors and with classes over, she was anxious to get back out in the field and start welding again. She had her own welding rig consisting of a Dodge 1-ton dually with the custom fabricated bed she and a friend built, a Lincoln SA-200 Pipeliner welder generator, and torch set. Even though she really enjoyed the opportunity to travel throughout many of the western states working as a welder-fabricator, she has moved back to southern Colorado. She currently works as an agricultural repair and fabrication welder in the La Junta area. Recently, she added a plasma cutter to her current welding rig. She said it has really made cutting out parts so much easier than it was when she only had an oxyacetylene cutting torch. Running the plasma cutting torch off of the welder generator s AC power outlet has made it a lot easier to cut everything, especially on thin sheet metal. The plasma torch doesn t distort sheet metal like the acetylene torch did, so it is easier and faster to make a fabrication. She loves to ride horses and rodeo a little and wants someday to save the money she earns from welding to buy a ranch and maybe help underprivileged kids by giving them the opportunity to experience the outdoor life that she has.
19 Acknowledgments xvii Acknowledgments To bring a book of this size to publication requires the assistance of many individuals, and the author and publisher would like to thank the following for their unique contributions to this and/or prior editions: Marilyn K. Burris, for the years of work on this text and graphics. The, Inc., whose Welding Journal was an invaluable source for many of the special-interest articles. John L. Chastain, who worked with the author for many long hours to perfect the photographic techniques required to achieve the action photos. Dewayne Roy, Welding Department chairman at Mountain View College, Dallas, Texas, for his many contributions to this text. The author would like to express his deepest appreciation to Thermal Dynamics and Jay Jones for all the props and help they provided for the preparation of this text. In addition he would like to thank Garland Welding Supply Co. Inc. for the loan of material and supplies for photo shoots. Ernest Levert, welding engineer at Lockheed Martin for all of his great technical advice and for sharing his welding experiences. Special thanks are due to the following companies for their contributions to the text: Skills USA- VICA; Praxair; NASA Media Research Center; Miller Electric Co.; Caterpillar, Inc.; ESAB Welding & Cutting Products; Frommelt Safety Products; Hornell Speedglas, Inc.; Mine Safety Appliances, Co.; Lincoln Electric; Jackson Products/Thermadyne; Thermadyne Holdings; Hobart Brothers Co.; Concoa Controls Corp.; Stanley Works; Rexarc; Magnaflux Corp.; Buehler Ltd.; T.J. Snow Co., Inc.; Victor Equipment; E.O. Paton Electric Welding Institute; CRC-Evans Automatic Welding; Cherry Point Refinery; The Aluminum Assoc./Automotive & Light Truck Group; E.I. DuPont de Nemours & Co.; Philips Gmbh; Technical Systems; GWS Welding Supply Co.; Merrick Engineering, Inc.; Reynolds Metals Co.; Liquid Air Corp.; Alphagaz Div.; American Torch Tip; ARC Machines, Inc.; FANUX Robotics North America, Inc.; Alexander Binzel Corp.; Sciaky Brothers, Inc.; Aluminum Co. of America; National Machine Co.; Leybold Heraeus Vacuum Systems, Inc.; Sonobond Ultrasonics; Foster Instruments; Prince & Izant Company; United Association of the Journeymen and Apprentices of the Plumbing and Pipe Fitting Industry of the United States and Canada, Local No. 100; Atlas Copco Drilling Solutions Inc; Garland Welding Supply Co., Inc.; and the City of Garland Texas: Garland Power and Light. The following individuals, who reviewed the sixth edition in anticipation of the seventh. Their recommendations have been invaluable to the author: David Parker, Renton Technical College; Gonzalo Huerta, Imperial Valley College; and Mark Prosser, Blackhawk Technical College. The following individuals, who are featured in the Success Stories in the text and Online Companion; they are valuable contributors to the textbook and an inspiration for those entering the welding industry: Danielle DiBari, Jared Corley, Kassandra Rieke, Michael Crumpler, Mike Vaughan, Stephan Pawloski, and Jay Jones. The author also would like to express his deepest appreciation to: The welding instructors at: Lexington Area Technical High School, SC; Worcester Technical High School, MA; Craven Community College, NC; Great Plains Technology Center, OK; Atlantic Technical Center, FL; El Camino Community College, CA; Wichita Area Technical College, KS; Antelope Valley College, CA; Blackhawk Technical College, WI; Wenatchee Valley College, WA; Tyler Junior College, TX; Midlands Technical College, SC; John A. Logan College, IL; Northwest Mississippi Community College, MS; Tarrant County College, TX; Greater Lowell Technical High School, MA; Long Beach City College, CA; Redding Area Community College, PA; College of the Ozarks, MO; Bessemer State Technical College, AL; York Technical College, SC; Lakeview High School, TX; Newberry County Career Center, SC; Palm Beach Community College, FL; Texas State Technical College, TX; Grand Rapids Community College, MI; Kilgore College, TX;
20 xviii Acknowledgments Tulsa Technology Center, OK; Calcasieu Parish School, LA; Florence-Darlington Technical College, SC; Jefferson High School, TX; Coastal Carolina Community College, NC; Los Angeles Unified School District, CA; Vatterott College, MO; New River Community College, VA; New Hampshire Technical College at Manchester, NH; and Austin Community College, TX, for sharing with me their welding experiences, teaching experiences, and students experiences, which have helped form the basis for many of the updates in this edition. Tina Ivey, Sam Burris, David DuBois, and Traywick Duffie for all their help in the preparation of this edition To my wife, Carol, for all of her moral support, and to my daughters, Wendy and Amy, for all of the general office help they provided.