1、VOLUME 1Welding Metallurgy Volume I, Fundamentals Dedicated to George Michael Linnert 1943-1952Welding Metallurgy Carbon and Alloy Steels Volume I Fundamentals George E. Linnert GML Publications Hilton Head Island, South Carolina, USA Fourth Edition Published by the American Welding Society Miami, F
2、lorida, USALibrary of Congress Catalog Card Number: 94-074489 International Standard Book Number: 0-87171-457-4 Copyright 1994 by the American Welding Society 550 N.W. LeJeune Road; Miami, Florida; USA Fourth Edition 1994 All rights reserved. No part of this book may be reproduced in any form or by
3、any means electronic or mechanical including pho- tocopying, recording, or any other information storage or retrieval system, without permission in writing from the publisher. The American Welding Society, Inc. assumes no responsibility for the information contained in this publication. An independe
4、nt, substanti- ating investigation should be made prior to reliance on or use of such information. Text edited, designed and formatted by Alexander M. Saitta Printed in the United States of AmericaContents Contents Chapter One: Background to Welding Metallurgy 1 MILESTONES IN WELDING HISTORY 1 THE F
5、UTURE OF WELDING 4 WHAT IS WELDING METALLURGY? 6 PUTTING WELDING METALLURGY TO USE 12 WELDING TECHNOLOGY RESOURCES 12 SUGGESTED READING 15 Chapter Two: The Structure of Metals 18 ATOMS 18 Elementary Particles 20 Electrons 22 Positrons 26 Atomic Nuclei 26 Protons 27 Neutrons 28 Atom Construction 32 I
6、sotopes of Elements 33 Isobars 34 Atomic Weight 34 Atomic Mass 34 Atom Valency 35 lonization 36 Radioactivity 37 Atom Size or Diameter 38 THE ELEMENTS 39 AGGREGATES OF ATOMS 41 The Solid State 45 The Crystalline Solids 45 Amorphous Solids 47 The Liquid State 48 The Gaseous State 49 FUNDAMENTALS OF C
7、RYSTALS 50 Identification of Planes and Directions in Crystals 56 Basic Types of Crystals 56vi Welding Metallurgy Inert Gas Crystals 58 Ionic Crystals 58 Covalent Crystals 59 Metallic Crystals 59 THE CRYSTALLINE STRUCTURE OF METALS 61 How Does a Crystal Grow from the Melt? 64 The Formation of Dendri
8、tes 66 The Formation of Grains 68 The Shape of Grains 71 The Size of Grains 72 Undercooling 72 THE IMPORTANCE OF A CRYSTALLINE STRUCTURE 74 Allotropic Transformation 75 Solubility in the Solid State 76 Plasticity in Metallic Crystals 77 Slip in Crystalline Structures 77 Slip and Lattice Orientation
9、78 Slip in Polycrystalline Metals 79 Observing Slip 80 Twinning in Crystalline Structures 81 Lattice Imperfections: Dislocations 84 Point Defects 85 Edge Dislocations 86 Screw Dislocations 88 Stacking Faults 88 Other Lattice Imperfections 88 Cold-Working Metals 88 EXAMINATION OF METAL STRUCTURES 91
10、Fracture Appearance Assessment 92 Metallography 92 Metallography Using Optical Microscopy 92 Quantitative Metallography 105 Metallography Using the Electron Microscope 106 Metallography Using Ion Microscopy 115 Tunnel-Effect Microscopy 116 Chemical Analysis of Microstructural Constituents 116 Newer
11、Techniques in Metallurgy 121 FRACTOGRAPHY 123 SUGGESTED READING 131 Chapter Three: The Properties of Metals 133 STRUCTURE SENSITIVITY OF PROPERTIES 133 DIRECTIONALITY IN PROPERTIES 135Contents vii MECHANICAL PROPERTIES 136 Elastic Behavior of Metals 137 Youngs Modulus of Elasticity 139 Poissons Rati
12、o 139 Limits of Elasticity and Proportionality 141 Plastic Yielding in Metals 142 Yield Strength 143 Breaking Strength of Metals 143 Tensile Strength 144 True Stress and True Strain 144 Notched Tensile Strength 147 Ductility 147 Elongation 148 Reduction of Area 149 Ductility Indications from Special
13、 Tests 149 Hardness 149 Static Indentation Hardness Testing 150 Microhardness Testing 151 Dynamic Hardness Testing 152 Scratch Hardness Testing 153 Conversion of Hardness Numbers 153 Toughness 154 Introduction of Impact Testing 155 FRACTURE IN METALS 156 Ductile Fracture 158 Brittle Fracture 159 Int
14、ergranular Fracture 162 Conditions Affecting Fracture Toughness 164 Effect of Temperature 164 Effect of Stress Axiality 166 Stress Gradient 169 Stress Multiaxiality 170 Effect of Rate of Strain 171 Effect of Cyclic Stress (Fatigue) 174 Fatigue Crack Initiation 176 Fatigue Crack Propagation 176 Fatig
15、ue Crack Failure 176 Cyclic Stress Limits to Avoid Fatigue Failure 181 Cyclic Stress Conditions 183 Variable Loading and Cumulative Fatigue Damage 185 FRACTURE MECHANICS: ASSESSMENT OF FRACTURE TOUGHNESS 188 Brittle Fracture Test Parameters 190 Section Dimensions 192 Plotting Coordinates 192 Crack S
16、urface Displacement Mode 193 Plane-Strain 195Viii Welding Metallurgy Plane-Stress 195 Stress Distribution 196 Procedures for Evaluating Propensity for Brittle Fracture 197 Use of Linear-Elastic Fracture Mechanics 198 Development of Elastic-Plastic Fracture Mechanics 201 Crack Tip Opening Displacemen
17、t Testing 205 The J-lntegral Test Method 211 Fatigue Cracking Assessment by Fracture Mechanics 215 Mechanical Properties at Low Temperature 218 Strength at Low Temperature 219 Impact Toughness at Low Temperature 220 Test Methods for Toughness Evaluation 226 Correlation of Results from Fracture Tough
18、ness Tests 236 Improved Mechanical Properties for Low-Temperature Service 238 Mechanical Properties at Elevated and High Temperatures 238 Short-Time Elevated Temperature Testing 241 Long-Time Elevated Temperature Testing 242 Mechanical Properties After Plastic Work 247 Hot Work 248 Cold Work 248 Pee
19、ning 248 Irradiation 249 PHYSICAL PROPERTIES 258 Density 258 Thermal Properties 259 Specific Heat 260 Thermal Conductivity 261 Melting Point or Melting Range 264 Heat of Fusion 264 Viscosity and Surface Tension of Molten Metals 264 Boiling Point and Heat of Vaporization 266 Thermal Expansion and Con
20、traction 266 Thermionic Work Function 268 Electrical Properties 268 Magnetic Properties 270 Evaluation of Magnetization 272 Summary of Magnetic Behavior 273 Involvement of Magnetization in Welding 274 CHEMICAL PROPERTIES 274 Corrosion of Metals 275 Corrosion in Aqueous Solutions 276 Corrosion in Hot
21、 Gases 282 Corrosion in Molten Metals 282 Corrosion in Molten Salt 283 Forms of Corrosion Pertinent to Weldments 283 Stress Corrosion Cracking (SCC) 284 SUGGESTED READING 293Contents ix Chapter Four: Effects of Alloying Elements 295 ALLOYING 295 Alloys in the Liquid State 296 Phase Diagrams 299 Bina
22、ry Phase Diagrams 304 Ternary Phase Diagrams 307 Phase Diagrams for Multi-Element Alloys 308 Alloys in the Solid State 310 Factors Influencing Solid Solubility 310 Formation of Intermediate Phases and Compounds 316 Mechanisms and General Effects of Alloying 316 Role of Crystalline Structure 317 Role
23、 of Microstructure 319 Mechanisms for Altering Mechanical Properties 319 ALLOYING ELEMENTS IN IRON 326 Carbon 329 Analysis of the Iron-Iron Carbide Diagram 331 Manganese 337 Phosphorus 338 Sulfur and Selenium 340 Silicon 342 Copper 343 Chromium 345 Nickel 346 Molybdenum 346 Niobium (Columbium) 347 V
24、anadium 348 Aluminum 348 Nitrogen 349 Titanium 352 Boron 354 Cobalt 355 Tungsten 355 Lead 355 Other Alloying Elements 356 BENEFIT OF REVERSING THE ALLOYING TREND 357 Residual Elements 358 SUGGESTED READING 359 Chapter Five: Types of Steel and Their Manufacture 361 GENERAL CATEGORIES OF IRON AND STEE
25、L 361 IRON PRODUCTION BY ORE REDUCTION 362 Blast Furnace 362Welding Metallurgy Direct Reduction Processes 365 CAST IRON 366 WROUGHT IRON 367 POWDER METALLURGY 367 STEELMAKING PROCESSES 368 Significance of Acid and Basic Steelmaking 368 Bessemer Converter 369 Open Hearth Furnace 370 Rimmed Steel 372
26、Capped Steel 373 Killed Steel 373 Semikilled Steel 379 Vacuum Deoxidized Steel 379 Oxygen Steelmaking 380 Basic Oxygen Steelmaking 380 L-D Process 381 Kaldo Process 383 Off-Gas BOF 383 Q-BOP Process 383 Lance-Bubbling-Equilibrium 385 Ladle Refining 385 Slag Removal 385 Mixing Capability 386 Alloying
27、 Additions 386 Vacuum Treatment 386 Temperature Adjustment 387 Desulfurization 388 Electric-Arc Furnace 389 Electric-Induction Furnace 389 Electroslag Remelting 391 SPECIAL MELTING PROCESSES 392 Vacuum Induction Melting 392 Vacuum Consumable-Electrode Remelting 393 Electron-Beam Melting 395 Argon-Ox
28、ygen Decarburization (AOD) 396 FOUNDRY AND STEEL MILL OPERATIONS 397 Ingot Steelmaking Practice 398 Continuous Casting of Steel 400 HOT WORKING OPERATIONS 404 Thermo-Mechanical Control Process (T-MCP) 406 COLD FINISHING 407 HEAT TREATMENT 408 CONTINUOUS COATING OF STRIP STEEL IN COILS 409 TYPES OF S
29、TEEL 410 Carbon Steels 410Contents xi Alloy Steels 411 Construction 412 Automotive, Aircraft, and Machinery 412 Low-Temperature Service 413 Elevated Temperature Service 413 High-Alloy Steels 413 Austenitic Manganese Steel 413 Stainless Steels 414 Heat-Resisting Steels 415 Tool Steels 415 STANDARDS A
30、ND SPECIFICATIONS FOR STEELS 416 Unified Numbering System 416 AISI-SAE System of Standard Carbon and Alloy Steels 418 ASTM Standards 420 API Specifications 424 Aerospace Material Specifications 426 ASME Material Specifications 426 AWS Specifications, Codes and Rules 429 CARBON AND ALLOY STEEL USED I
31、N WELDED CONSTRUCTION 430 Qualities of Steel Important to Welding 431 Factors Affecting the Weldability of Steel 432 Chemical Composition 432 Mechanical Properties 434 Metallurgical Structure 435 Internal Soundness 435 Cleanliness 436 THE FUTURE OF STEELS AND THEIR WELDABILITY 437 New Steels and Pro
32、duct Forms 437 Dissimilar-Metal Welding 437 Repair Welding The Ultimate Challenge 439 SUGGESTED READING 439 Chapter Six: Welding Methods and Processes 444 SOLID-STATE WELDING (SSW) 444 FUSION WELDING 445 BRAZING AND SOLDERING 445 HEAT SOURCES FOR WELDING AND CUTTING 448 Electrical Heat Generation 44
33、8 Electric Arc 448 Electron Beam 459 Electric Resistance 461 Electromagnetic Radiation 461 Laser Beams 463xii Welding Metallurgy Chemical Heat Generation 465 Mechanical Heat Generation 466 THE WELDING AND CUTTING PROCESSES 467 Arc Welding Process 467 Power Sources for Arc Welding 467 Auxiliary Equip
34、ment for Arc Welding 470 Basic Forms of Arc Welding 471 Shielded Metal Arc Welding (SMAW) 472 Stud Arc Welding (SW) 477 Gas Tungsten Arc Welding (GTAW) 478 Gas Metal Arc Welding (GMAW) 489 Flux Cored Arc Welding (FCAW) 501 Submerged Arc Welding (SAW) 505 Plasma Arc Welding (PAW) 511 Percussion Weldi
35、ng (PEW) 514 Magnetically Impelled Arc Welding 515 Welding Arc Technology 517 Resistance Welding Processes 520 Resistance Spot Welding (RSW) 522 Resistance Seam Welding (RSEW) 531 Projection Welding (PW) 532 Upset Welding (UW) 533 Flash Welding (FW) 537 Electrical Metal-Explosion Welding Process 541
36、 Induction Welding (IW) 542 Electroslag Welding (ESW) 542 Electron Beam Welding (EBW) 548 Welding in a High Vacuum (EBW-HV) 550 Welding in a Medium Vacuum (EBW-MV) 565 Nonvacuum Electron Beam Welding (EBW-NV) 565 Tracking Joints During Electron Beam Welding 565 Laser Beam Welding (LBW) 568 Nature of
37、 Laser Beams and Plasma Generation 569 Basic Techniques in Laser Welding 571 Attributes of Laser Welding 571 Laser Welding Difficulties and Defects 572 Shielding Gas Effects in Laser Welding 575 Filler Wire Feeding in Laser Welding 576 Oxyfuel Welding (OFW) 582 Oxyacetylene Welding (OAW) 582 Thermit
38、e Welding (TW) 585 SOLID-STATE WELDING PROCESSES 587 Hot Pressure Welding (HPW) 589 Induction Welding (IW) 592 Friction Welding (FRW) 593 Inertia-Drive Friction Welding 594 Direct-Drive Friction Welding 595Contents xiii Materials Suited for Friction Welding 595 Mechanical Properties of Friction Weld
39、s 598 Other Forms of Friction Welding 600 Explosion Welding (EXW) 607 Diffusion Welding (DFW) 612 Ultrasonic Welding (USW) 613 Cold Welding (CW) 616 Electrostatic Bonding 617 Electrodeposition Welding 619 BRAZING AND SOLDERING PROCESSES 620 Brazing Processes (B) 620 Soldering (S) 624 SURFACING BY WE
40、LDING AND THERMAL SPRAY 628 Buildup 628 Buttering 628 Hardfacing 629 Overlaying and Cladding 632 THERMAL CUTTING PROCESSES 633 Metallurgical Effects of Thermal Cutting 633 Oxygen Cutting Processes (OC) 634 Oxyfuel Gas Cutting (OFC) 635 Chemical Flux Cutting (FOC) 636 Metal Powder Cutting (POC) 636 E
41、lectric Arc Cutting Processes (AC) 637 Air Carbon Arc Cutting (CAC-A) 639 Plasma Arc Cutting (PAC) 640 Electron Beam Cutting (EBC) 643 Laser Beam Cutting (LBC) 647 SUGGESTED READING 651 Chapter Seven: Temperature Changes in Welding 653 TERMS AND DEFINITIONS 653 Heat 653 Temperature 654 Thermal Flow
42、654 Conduction, Convection, and Radiation 655 Enthalpy and Entropy 656 TEMPERATURE AND TIME IN WELDING 656 Heat Flow Equations 657 Heat Source Characterization 658 Rate of Heating 659 Heating Potential of Energy Sources 661 OAW Heating Potential 662 AW Heating Potential 662xiv Welding Metallurgy FRW
43、 Heating Potential 662 EBW Heating Potential 663 LBW Heating Potential 663 Electrical Resistance Heating Potential 663 Peak Temperatures 664 Defining the Weld Zone 665 Numerical Modeling of Temperatures 666 Temperature Distributions 668 Effects of Temperature Distribution on Cooling Rate 670 Special
44、 Considerations Regarding Temperature Distribution 672 Time at Temperature 674 Furnace Heating for Welding Simulation 675 Temper Color as an Indicant 675 Resistance Heating for Welding Simulation 676 Cooling Rate of Heated Zones 677 Correlation with Heat Input 677 Workpiece Pre-Weld Temperature 681
45、Instantaneous Cooling Rate 683 Influence of Travel Speed on Weld Zone Size 686 Hardness/Microstructure/CoolingRate Relationship 693 Cooling End Points 696 CONTROL OF TEMPERATURE IN FUSION WELDING 698 Predictive Diagrams for Fusion Welding Parameters 699 Mathematical Modeling of Fusion Welding 699 Se
46、nsory Systems for Adaptive Control of Fusion Welding 701 Adaptive Control of Solid-State Welding Processes 703 SUGGESTED READING 705 Chapter Eight: Fluxes, Slags, and Gases for Shielding 708 OXIDATION OF IRON 708 OXIDATION OF STEEL 710 Carbon/Oxygen Reaction in Molten Steel 710 Oxidation of Solid St
47、eel 713 PREVENTING OXIDATION DURING WELDING 714 Shielding Slags 714 Fluxes 716 Controlled Atmospheres 717 Vacuum 718 Technique 720 Deoxidizers 721 Protective Surface Alloys 721 Liquid Blankets 722 SHIELDING THE JOINING PROCESSES FROM AIR 722 Carbon Arc Welding 722Contents xv Metal Arc Welding 723 Co
48、vered Electrodes 724 Generic Electrode Coverings and Typical Formulas 731 Flux Cored Electrodes 738 Submerged Arc Welding (SAW) 744 Types of SAW Fluxes and Their Classification 744 Methods of Manufacturing SAW Fluxes 748 Physical Chemistry of Fluxes in SAW Process 750 Transfer of Elements Between SA
49、W Flux/Slag and Weld Metal 758 Electroslag Welding 765 Gas Shielded Arc Welding 766 Argon 768 Helium 768 Carbon Dioxide 769 Propane 770 Nitrogen 770 Hydrogen 770 Miscellaneous Gas Additives 771 Gas Tungsten Arc Welding 771 Gas Metal Arc Welding 772 Globular Transfer in GMAW 775 Repelled Transfer in GMAW 775 Projected Transfer in GMAW 776 Streaming or Axial-Spray Transfer in GMAW 776 Pulsed Spray Transfer in GMAW-P 777 Rotating Droplet (Kinking) Transfer in GMAW 778 Explosive Drop Transfer in GMAW 778 Short Circuiting Transfer in GMAW-S 778 Flux Cored Arc Welding (FCAW) 779 Plasma Arc
