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 |  موضوع: كتاب Operator's Circular Welding Theory and Application الجمعة 22 نوفمبر 2024, 1:17 am | |
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أحضرت لكم كتاب
Operator's Circular Welding Theory and Application
و المحتوى كما يلي :
REPORTING ERRORS AND RECOMMENDING IMPROVEMENTS
Training Circular
No. 9-237
TC 9-237
HEADQUARTERS
DEPARTMENT OF THE ARMY
Washington, DC, 7 May 1993
You can help improve this circular. If you find any mistakes or if you know
of a way to improve the procedures, please let us know. Mail your letter or
DA Form 2028 (Recommended Changes to Publications and Blank Forms), located
in the back of this manual, direct to: Commander, US Army Ordnance Center
and School, ATTN: ATSL-CD-CS, Aberdeen Proving Ground, MD 21005-5201. A
reply will be furnished to you.
Table of Contents
Paragraph Page
CHAPTER 1. INTRODUCTION
Section I. General 1-1 1-1
II. Theory 1-3 1-1
CHAPTER 2.
Section I.
SAFETY PRECAUTIONS IN WELDING OPERATIONS
General Safety Precautions
Safety Precautions in Oxyfuel Welding
Safety in Arc Welding and Cutting
Safety Precautions for Gas Shielded Arc Welding
Safety Precautions for Welding and Cutting
Containers That Have Held Combustibles
Safety Precautions for Welding and Cutting
Polyurethane Foam Filled Assemblies
2-1
2-6
2-12
2-17
2-19
2-30
2-1
2-14
2-22
2-27
2-28
2-38
CHAPTER 3. PRINT READING AND WELDING SYMBOLS
Section I. Print Reading 3-1 3-1
II. Weld and Welding Symbols 3-4 3-3
CHAPTER 4. JOINT DESIGN AND PREPARATION OF METALS 4-1 4-1
CHAPTER 5.
Section I.
II.
III.
IV.
V.
VI.
WELDING AND CUTTING EQUIPMENT
Oxyacetylene Welding Equipment
Oxyacetylene Cutting Equipment
Arc Welding Equipment and Accessories
Resistance Welding Equipment
Thermit Welding Equipment
Forge Welding Tools and Equipment
DISTRIBUTION RESTRICTION: Approved for public release; distribution is
unlimited.
iTC 9-237
Table of Contents (cont)
Paragraph Page
CHAPTER 6. WELDING TECHNIQUES
Section I. Description 6-1 6-1
II. Nomenclature of the Weld 6-7 6-14
III. Types of Welds and Welded Joints 6-10 6-20
xv . ricxvxxiAy ruaxLiuili O“1 / 6“JU
V. Expansion and Contraction in Welding Operations 6-25 6-38
VI. Welding Problems and Solutions 6-29 6-47
CHAPTER 7. METALS IDENTIFICATION
Section I. Characteristics 7-1 7-1
II. Standard Metal Designations 7-4 7-37
III. General Description and Weldability of Ferrous
Metals 7-10 7-45
IV. General Description and Weldability of Nonferrous
Metals 7-17 7-66
CHAPTER 8. ELECTRODES AND FILLER METALS
Section I. Types of Electrodes 8-1 8-1
II. Other Filler Metals 8-4 8-14
CHAPTER 9. MAINTENANCE WELDING OPERATIONS FOR MILITARY
EQUIPMENT 9-1 9-1
CHAPTER 10. ARC WELDING AND CUTTING PROCESSES
Section I. General 10-1 10-1
II. Arc Processes 10-8 10-23
III. Related Processes 10-15 10-102
CHAPTER 11. OXYGEN FUEL GAS WELDING PROCEDURES
Section I. Welding Processes and Techniques 11-1 11-1
II. Weldina and Brasri’ncr Fat-taiid Met-alc 11—17 11-07
III. Related Processes 11-17 11-32
IV. Welding, Brazing, and Soldering Nonferrous Metals .... 11-19 11-41
CHAPTER 12. SPECIAL APPLICATIONS
Section I. Underwater Cutting and Welding with the Electric
Arc
: 12-1 12-1
II. Underwater cutting with Oxyfuel 12-4 12-5
III. Metallizing 12-6 12-6
TV rs.4-4-^
J.V. 1XO11C xuLujjiy — Ol_eex r; 1 cuma xxun T 1Z-1O . -> . r- IZ-lb , ,
V. Flame Treating Metal 12-20 12-24
VI. Cutting and Hard Surfacing with the Electric Arc 12-27 12-27
VII. Armor Plate Welding and Cutting 12-33 12-31
VIII. Pipe Welding 12-41 12-54
LX. Welding Cast Iron, Cast Steel, Carbon Steel,
and Forgings 12-46 12-65
X. Forge Welding 12-48 12-71
XI. Heat Treatment of Steel 12-50 12-72
XII. Other Welding Processes 12-60 12-80TC 9-237
Paragraph Page
CHAPTER 13. DESTRUCTIVE AND NONDESTRUCTIVE TESTING
Section I. Performance Testing 13-1 13-1
II. Visual Inspection and Corrections 13-4 13-2
III. Physical Testing 13-12 13-8
APPENDIX A. REFERENCES ... A-l A-l
APPENDIX B. PROCEDURE GUIDES FOR WELDING ... B-l B-l
APPENDIX C. TROUBLESHOOTING PROCEDURES ... C-l C-l
APPENDIX D. MATERIALS USED FOR BRAZING, WELDING, SOLDERING,
CUTTING, AND METALLIZING ...D-l D-l
APPENDIX E. MISCET.1ANEOUS DATA ... E-l E-l
GLOSSARY . ...G-l G-l
INDEX 1-1 Index-1TO 9-237
LIST OF ILLUSTRATIONS
Figure Title Page
2-1 Welding helmet and hand-held shield 2-2
2-2 Welding helmets and shields 2-4
2-3 Safety goggles 2-5
2-4 Protective clothing 2-5
2-5 Welding booth with mechanical ventilation 2-10
2-6 Process diagram for air carbon arc cutting 2-25
2-7 Circuit block diagram AAC 2-26
2-8 Safe way to weld container that held combustibles 2-37
3-1 Construction lines 3-3
3-2 Standard locations of elements of a welding symbol 3-4
3-3 Basic and supplementary arc and gas welding symbols 3-5
3-4 Process or specification references 3-5
3-5 Definite process reference 3-6
3-6 No process or specification reference 3-6
3-7 Weld-all-around and field weld symbols 3-8
3-8 Resistance spot and resistance seam welds 3-8
3-9 Arrow side fillet welding symbol 3-8
3-10 Other side fillet welding symbol 3-8
3-11 Plug and slot welding symbols indicating location and dimensions
of the weld 3-9
3-12 Arrcw side V groove welding symbol 3-9
3-13 Other side V groove welding symbol 3-9
3-14 Welds on the arrow side of the joint 3-10
3-15 Welds on the other side of the joint 3-10
3-16 Welds on both sides of joint 3-10
3-17 Spot, seam, and flash or upset weld symbols 3-10
3-18 Construction of symbols, perpendicular leg always to the left .. 3-12
3-19 Construction of symbols, arrow break toward chamfered member ... 3-12
3-20 Construction of symbols, symbols placed to read left to right .. 3-13
3-21 Combinations of weld symbols 3-13
3-22 Complete penetration indication 3-13
3-23 Construction of symbols, special types of welds 3-14
3-24 Multiple reference lines 3-14
3-25 Supplementary data 3-14
3-26 Supplementary symbols 3-14
3-27 Dimensions of fillet welds 3-15
3-28 Combined intermittent and continuous welds 3-16
3-29 Extent of fillet welds 3-16
3-30 Dimensions of chain intermittent fillet welds 3-17
3-31 Dimensions of staggered intermittent fillet welds 3-17
3-32 Application of dimensions to intermittent fillet weld symbols .. 3-17
3-33 Surface contour of fillet welds 3-18
3-34 Plug and slot welding symbols indicating location and dimensions
of the weld ' 3-19
3-35 Surface contour of plug welds and slot welds 3-20
3-36 Surface contour of plug welds and slot welds with user's
standard finish symbol 3-20
3-37 Slot weld dimensions 3-20
3-38 Dimensions of arc spot and arc seam welds 3-21
3-39 Extent of arc spot welding 3-21
ivTC 9-237
3-40 Number of arc spot welds in a joint 3-22
3-41 Surface contour of arc spot and arc seam welds 3-22
3-42 Groove weld dimensions 3-22
3-43 Groove weld dimensions having no general note 3-23
3-44 Groove welds with differing dimensions 3-23
3-45 Groove weld dimensions for welds extending through the members
joined 3-23
3-46 Groove weld dimensions for welds extending partly through the
members joined 3-24
3-47 Dimensions of groove welds with specified root penetration 3-24
3-48 Flare groove welds 3-24
3-49 Root opening 3-25
3-50 Back or backing weld symbol 3-25
3-51 Surface contour of groove welds 3-25
3-52 Contours ohtai n^d by welding 3-26
3-53 Flush contour by machining 3-26
3-54 Convex contour by machining 3-26
3-55 Surface contour of back or backing welds 3-27
3-56 Melt-thru weld symbol 3-27
3-57 Surface contour of melt-thru welds 3-27
3-58 Size of surfaces built up by welding 3-28
3-59 Flange weld symbols 3-29
3-60 Size of resistance spot welds 3-30
3-61 Strength of resistance spot welds 3-30
3-62 Spacing of resistance spot welds 3-30
3-63 Extent of resistance spot weld 3-31
3-64 Number of resistance spot welds 3-31
3-65 Contour of resistance spot welds 3-31
3-66 Size of resistance seam welds 3-32
3-67 Strength of resistance seam welds 3-32
3-68 Length of resistance seam welds 3-32
3-69 Extent of resistance seam welds 3-33
3-70 Dimensioning of intermittent resistance seam welds 3-33
3-71 Contour of resistance seam welds 3-33
3-72 Embossment on arrow-side member of joint for projection
welding 3-34
3-73 Embossment on other-side member of joint for projection
welding 3-34
3-74 Diameter of projection welds 3-35
3-75 Strength of projection welds 3-35
3-76 Spacing of projection welds 3-35
3-77 Number of projection welds 3-35
3-78 Extent of projection welds 3-36
3-79 Contour of projection welds 3-36
3-80 Surface contour of lash or upset welds 3-36
4-1 The five basic types of joints 4-1
4-2 Inaccessible welds 4-4
5-1 Stationary oxygen cylinder manifold and other equipment 5-1
5-2 Station outlet for oxygen or acetylene 5-2
5-3 Stationary acetylene cylinder manifold and other equipment 5-2
5-4 Acetylene generator and operating equipment 5-3
5-5 Portable oxyacetylene welding and cutting equipment 5-4
5-6 Acetylene cylinder construction 5-6
5-7 Oxygen cylinder construction 5-8
vTC 9-237
LIST OF ILLUSTRATIONS (cont)
Title Page
5-8 Single stage oxygen regulator 5-9
5-9 Two stage oxygen regulator 5-11
5-10 Mixing head for injector type welding torch 5-12
5-11 Equal pressure type general purpose welding torch 5-12
5-12 Oxyacetylene cutting torch 5-19
5-13 Diagram of oxyacetylene cutting tip 5-19
5-14 Cutting attachment for welding torch 5-20
5-15 Making a bevel on a circular path with a cutting machine 5-20
5-16 Machine for making four oxyacetylene cuts simultaneously 5-21
5-17 Cutaway view of DC welding genera 5-23
5-18 Direct current welding martine 5-24
5-19 Alternating current arc welding machine 5-25
5-20 Gas tungsten-arc welding setup 5-26
5-21 Argon regulator with flowmeter 5-27
5-22 TIG welding torch 5-27
5-23 MIG welding torch 5-29
5-24 Connection diagram for MIG welding 5-30
5-25 Metal-arc welding electrode holders 5-35
5-26 Atomic hydrogen welding torch 5-35
5-27 Chipping hairmer and wire brush 5-35
5-28 Welding tabie 5-36
5-29 Molten metal transfer with a bare electrode 5-38
5-30 Arc action obtained with a light coated electrode *... 5-39
5-31 Arc action obtained with a shielded arc electrode 5-39
5-32 Electrode drying ovens 5-41
5-33 Correct electrode taper 5-41
5-34 Polarity of welding current 5-42
5-35 Effect of polarity on weld shape 5-43
5-36 AC wave 5-44
5-37 Rectified ac wave 5-44
5-38 Comparison of penetration contours 5-45
5-39 Resistance spot welding machine and accessories 5-47
5-40 Projection welding 5-49
5-41 Thermit welding crucible and mold 5-51
5-42 Portable forge 5-52
5-45 Blacksmith's anvil 5-53
6-l Chart of welding processes 6-1
6-2 Equipment setup for arc stud welding 6-2
Equipment setup for gas shielded arc stud welding 6-3
6-4 Submerged arc welding process 6-3
6-5 Gas tungsten arc welding 6-4
6-6 Gas metal arc welding 6-5
6-7 Shielded metal arc welding 6-5
6-8 Furnace brazing operation 6-8
Typical induction brazing coils and joints 6-9
6-10 Chemical bath dip brazing 6-9
6-11 Infrared brazing apparatus 6-10
6-12 Steps in making a thermit weld 6-13
6-13 Nomenclature of welds 6-14
Heat affected zones in a multipass weld 6-16
VITC 9-237
vii
6-16 6-15 Welding Basic joint procedure types schedule—various welds 6-17 6—21
6-17 Butt joints in light sections 6-21
6-18 Butt joints in heavy sections 6-21
6-19 Comer joints for sheets and plates 6-22
6-20 Edge joints for light sheets and plates 6-23
6-21 Lap joints 6-23
6-22 Tee joint-single pass fillet weld 6-24
6-23 Edge preparation for tee joints 6-24
6-24 Applications of fillet welds
6-25 Basic groove welds —single and double 6-25 6-25
6-26 Typical weld joints 6-26
6-27 Types of groove welds 6-27
6-28 Surfacing, plug, and slot welds 6-28
6-29 Flash, seam, spot, and upset welds 6-29
6-30 6-31 Welding Welding positions positions—groove welds—plate 6-30
6-32 Welding positions——fillet pipe welds welds—plate 6-30 6-31
6-33 Diagram of tack welded pipe on rollers 6-33
6-34 Diagram of horizontal pipe weld with uphand method 6-33
6-35 Diagram of horizontal pipe weld with downhand method 6-34
6-36 Vertical pipe fixed position weld with backhand nethod 6-35
6-37 Deposition of root, filler, and finish weld beads 6-35
6-38 Work angle—fillet and groove weld 6-36
6-39 Travel angle—fillet and groove weld 6-36
6-40 Forehand welding 6-37
6-41 Backhand welding 6-37
6-42 Results of weld metal shrinkage 6-38
6-43 Methods of counteracting contractions 6-39
6-44 Quench plates Used in the welding of sheet metal 6-40
6-45 Fixture used in the welding of sheet metal 6-41
6-46 Controlling expansion and contraction of cas-Hnga by
preheating 6-41
6-47 Cube of metal showing expansion 6-42
6-48 Longitudinal (L) and transverse (T) shrinkage stresses
in a butt weld 6-43
6-49 Longitudinal (L) and transverse (T) shrinkage stresses
in a fillet wald 6-43
6-50 Distortion in a butt weld 6-44
6-51 Distortion in a fillet weld 6-44
6-52 The order in which to make weld joints 6-46
6-55 6-54 6-53 Ductile Butt Edge welded welded fracture joint jointsurface — —residual residual stress stress pattern pattern 6-53 6-49 6-48
6-56 Brittle fracture surface 6-54
6-57 Fatigue fracture surface 6-56
6-58 Comer joint 6-58
6-59 Tee joint 6-58
6-60 Redesigned comer joint to avoid lamellar tearing 6-59
6-61 Effect of ground location on magnetic arc below 6-61
6-62 Unbalanced magnetic force due to current direction change 6-62
6-63 Unbalanced magnetic force due to unbalanced magnetic path 6-63
6-64 Reduction of magnetic force due to induced fields 6-64
7-1 Tensile strength 7-5TC 9-237
LIST OF ILLUSTRATIONS
F1^6 Title Page
7-2 Shear strength ?_5
"7-3 Compressive strength g_g
7-4 Characteristics of sparks generated by the grinding of metals .. 7-12
7-5 Blast furnace '
7-1g
7-6 Conversion of iron ore into cast iron, wrought iron, and
steel 7-ig
7-7 How steel qualities change as carbon is added 7-45
7-8 Weld preparation 7-46
7-9 Heat input nomograph 7-57
7-10 Studding method for cast iron repair 7-65
7-11 Joint design for aluminum plates 7-69
7-12 Aluminum joint designs for gas metal-arc welding processes 7-73
7-13 Joint preparation for arc welding magnesium 7-87
7-14 Position of torch and welding rod 7-89
7-15 Minimizing cracking during welding 7-90
7-16 Baffle arrangements to improve shielding 7-99
7-17 Trailing shield 7-99
7-18 Backing fixtures for butt welding heavy plate and thin sheet ... 7-100
7-19 Use of weld backup tape 7-101
8-1 Transfer of metal across the arc of a bare electrode 8-7
8~2 Deposition rates of steel flux-cored electrodes 8-13
8-3 Correct electrode taper 8-15
10-1 Characteristic curve for welding power source 10-3
10”2 Curve for single control welding machine 10-3
10-3 Curve for dual control welding machines 10-4
10-4 Volt ampere slope vs welding operation 10-5
10-5 Volt ampere curve for true constant current machine 10-7
10-6 Pulsed current welding 10-8
10-7 Burn-off rates of wire vs current 10-9
10-8 Static volt amp characteristic curve of CV machine 10-10
10-9 Static volt amp curve with arc range 10-10
10-10 Various slopes of characteristic curves 10-11
10-11 Current density—various electrode signs 10-12
10-12 Electrical circuit 10-13
10-13 Welding electrical circuit 10-14
10-14 Arc characteristic volt amp curve 10-16
10-15 The de tungsten arc 10-17
10-16 Arc length vs voltage and heat 10-18
10-17 The de shielded metal arc 10-19
10-18 The de consumable electrode metal arc 10-20
10-19 Sine wave generation 10-21
10-20 Sequences in multilayer welding 10-23
10-21 Schematic drawing of SMAW equipment 10-24
10-22 Elements of a typical welding circuit for shielded metal arc
welding 10-25
10-23 Three types of free-flight metal transfer in a welding arc 10-25
10-24 Travel speed limits for current levels used for 1/8-inchdiameter E6010 SMAW electrode. Dashed lines show travel speed
limits as determined by amount of undercut and bead shape .... 10-26
vi iiTC 9-237
10-25 Travel speed limits for current levels used for 1/8-inchdiameter EGO11 SMAW electrode. Dashed lines show travel speed
limits as determined by amount of undercut and bead shape .... 10-27
10-26 Travel speed limits for current levels used for 1/8-inchdiameter E6013 SMAW electrode. Dashed lines show travel speed
limits as determined by amount of undercut and bead shape .... 10-27
10-27 Travel speed limits for current levels used for 1/8-inchdiameter E7018 SMAW electrode. Dashed lines show travel speed
limits as determined by amount of undercut and bead shape .... 10-28
10-28 Travel speed limits for current levels used for 1/8-inchdiameter E7024 SMAW electrode. Dashed lines show travel speed
limits as determined by amount of undercut and bead shape 10-28
10-29 Travel speed limits for current levels used for 5/32-inchdiameter E8018 SMAW electrode. Dashed lines show travel speed
limits as determined by amount of undercut and bead shape 10-29
10-30 Travel speed limits for current levels used for 1/8-inchdiameter E11018 SMAW electrode. Dashed lines show travel
speed limits as determined by amount of undercut and bead
shape 10-29
10-31 Shielded metal arc welding 10-32
10-32 Gas tungsten arc (TIG) welding (GTAW) 10-33
10-33 Gas tungsten arc welding equipment arrangement 10-34
10-34 Technique for manual gas tungsten arc (TIG) welding 10-37
10-35 Process diagram - keyhole mode - PAW 10-38
10-36 Cross section of plasma arc torch head 10-39
10-37 Transferred and nontransferred plasma arcs 10-43
10-38 Various joints for plasma arc 10-45
10-39 Circuit diagram - PAW 10-45
10-40 Quality and cannon faults 10-45
10-41 Deposition rates 10-47
10-42 Typical air cooled carbon electrode holders 10-48
10-43 Process diagram - CAW 10-50
10-44 Gas metal arc welding process 10-55
10-45 MIG welding process 10-55
10-46 Typical semiautomatic gas-cooled, curved-neck gas metal arc
welding gun 10-57
10-47 Variation in volumes and transfer rate of drops with welding
current (steel electrode) 10-61
10-48 Voltage versus current for E70S-2 1/16-inch-diameter electrode
and shield gas of argon with 2-percent oxygen addition 10-63
10-49 Voltage versus current for E70S-2 1/16-inch-diameter electrode
and carbon dioxide shield gas 10-63
10-50 Voltage versus current for E70S-3 1/16-inch-diameter electrode
and shield gas of argon with 2-percent oxygen addition 10-84
10-51 Voltage versus current for E70S-3 1/16-inch-diameter electrode
and carbon dioxide shield gas 10-84
10-52 Voltage versus current for E70S-4 1/16-inch diameter electrode
and carbon dioxide shield gas 10-65
10-53 Voltage versus current for E70S-6 1/16-inch-diameter electrode
and carbon dioxide shield gas 10-65
10-54 Voltage versus current for E110S 1/16-inch-diameter electrode
and shield gas of argon with 2-percent oxygen addition 10-66
10-55 Flux-cored arc welding process 10-68
10-56 Equipment for flux-cored arc welding 10-69
10-57 Wire feed assembly 10-70
LxTC 9-237
LIST OF ILLUSTRATIONS
Figure
10-58
10-59
10-60
10-61
10-62
10-63
10-64
10-65
10-66
10-67
10-68
10-69
10-70
10-71
10-72
10-73
10-74
10-75
10-76
10-77
10-78
10-79
10-80
11-1
11-2
11-3
11-4
11-5
11-6
11-7
11-8
11-9
11-10
11-11
11-12
11-13
11-14
11-15
11-16
11-17
11-18
11-19
11-20
12-1
12-2
12-3
12-4
in tr
12-6
12-7
Title Page
Cross-section of a flux-cored wire
Block diagram—SAW *’
Weld Process joint diagram designs —submerged for submerged arc welding arc welding
Deposition rates for single electrodes .....'.
Welds corresponding to table 10-23 ’'’*
Stickout vs deposition rate
Welding on rotating cirmlar parts
Angle of slope of work vs weld ’
Angle of electrode vs weld ”
Two electrode wire svstens .
Strip electrode on surfacing
Welding with iron powder additives
Plasma arc torch terminology
Basic plasma arc cutting circuitry
Dual flow plasma arc cutting
Water injection plasma arc cutting arrangement
Process diagram for air carbon arc cutting ’
Air carbon arc cutting diagram
Resistance spot welding process
Flash welding
Electron beam welding process
The temperature of the flame ’''
Oxyacetylene flames
What MAPP gas flames should look like
Forehand welding
Backhand welding
The fillet used to make the five basic joints
Fillet weld throat dimension
Fillet weld size vs strength
Welding position—fillet and groove welds
Welding a butt joint in the horizontal position
Bead welding without a welding rod '.*.W
Bead welding with a welding rod
Position of rod and torch for a butt weld in a flat position ..'
Wo1 i nrr a - » •__ i • j_ •
j_u uiie veircxcax position
Welding a butt joint in the overhead position
Silver braseiner -ioi n-t-^
Starting a cut and cutting with a cutting torch
Procedure for oxyacetylene cutting of cast iron
Coupling distance
Torch angle ******
Arrangements for underwater welding
The wire metallizing process
Electric arc spraying process
Flame spray process
Plasma spray process
Process diagram of oxygen cutting
Manual oxygen cutting torch
10-73
10-83
10-85
10-88
10-90
10-92
10-96
10-97
10-97
10-98
i n nn
1U"77
10-100
10-101
10-102
10-105
10-106
10-107
10-108
10-109
10-113
10-116
10-118
10-120
11-7
11-8
11-11
11-13
11-14
11-15
11-16
11-16
11-18
11-19
11-20
11-20
11-21
11-22
11-23
11-32
11-34
11-35
11-39
11-39
12-3
12-6
12-11
12-13
12-13
12-17
12-19TC 9-237
12-8 Methods of preparing joints 12-19
12-9 Procedure for oxyacetylene cutting of cast iron 12-23
12-10 Operations and time intervals in flame descaling prior to
painting 12-25
12-11 Removal of countersunk rivets .. 12-26
12-12 Removal of buttonhead rivets 12-27
12-13 Method of cutting stainless steel welds 12-34
12-14 Method of removing surface defects frcm stainless steel welds .. 12-35
12-15 Preparation for welding cracks in homogenous armor plate 12-37
12-16 Backing methods for depositing weld beads at the root of a
double V joint 12-38
12-17 Sequence of passes when depositing weld beads on homogenous
armor plate 12-39
12-18 Carmon defects when welding root beads on homogenous armor
plate and the remedial procedures 12-40
12-19 Procedure for welding single V joint on homogenous armor
plate 12-41
12-20 Double V weld on homogenous armor plate 12-42
12-21 Butt strap welds on cracked armor plate 12-43
12-22 Emergency repair of shell penetration through armor 12-44
12-23 Double V plug welding procedure for repairing shell penetration
in homogenous armor plate 12-44
12-24 Correct and incorrect plug weld preparation for repairing shell
penetration in homogenous armor plate 12-45
12-25 Welding homogenous armor without welding butt strap 12-47
12-26 Welding repair of gouges in surface of homogenous armor plate .. 12-47
12-27 Welding joint data for butt welds on face hardened armor 12-49
12-28 Use of butt strap on face hardened armor to repair cracks or
gaps * 12-50
12-29 Butt strap weld on face hardened armor 12-51
12-30 Weld joint data for corner welds on face hardened armor plate .. 12-51
12-31 Procedure for welding face hardened armor over 1/2 in. thick,
using the double V joint method 12-52
12-32 Procedure for welding face hardened armor up to 1/2 in., using
the depressed joint method 12-53
12-33 Seal bead weld 12-54
12-34 Angle iron serving as jig for small diameter pipe 12-55
12-35 Types of backing rings 12-56
12-36 Template pattern, ell joint, first step 12-58
12-37 Template pattern, ell joint, second step 12-58
12-38 Template pattern, ell joint, third step 12-59
12-39 Tee joint 12-59
12-40 Template pattern, tee joint, first step 12-60
12-41 Tenplate pattern, tee joint, second step 12-60
12-42 Diagram of tack welded pipe on rollers 12-62
12-43 Diagram of horizontal pipe weld with uphand method 12-62
12-44 Diagram of horizontal pipe weld with downhand method 12-63
12-45 Vertical pipe fixed position weld with backhand method 12-64
12-46 Deposition of root, filler, and finish weld beads 12-64
12-47 Studding method for cast iron repair 12-67
12-48 Forge welds 12-72
12-49 Muffle jacket 12-78
12-50 Schematic diagram of resistance spot welder 12-81
12-51 Schematic diagram of upset and flash welder 12-82
xiTC 9-237
LIST OF ILLUSTRATIONS
Figure Title Page
13-1 Guided bend test jig 13-9
13-2 Guided bend test specimens 13-9
13-3 Guided bend and tensile strength test specimens 13-10
13-4 Free bend test of welded metal 13-11
13-5 Nick break test 13-12
13-6 Tensile strength test specimen and test method 13-13
13-7 Portable tensile strength and bend testing machine 13-13
13-8 Internal weld defects disclosed by X-ray inspection 13-15
C-l Distortion C-18
C-2 Warping C-18
C-3 Poor appearance C-l9
C-4 Stress cracking C-19
C-5 Poor penetration C-19
C-6 Porous weld c-20
C-7 Poor fusion C-20
LIST OF TABLES
Number Title Page
2-1 Lens Shades for Welding and Cutting 2-3
2-2 Required Exhaust Ventilation 2-10
3-1 Designation of Welding Process by Letters 3-6
3-2 Designation of Cutting Processes by Letters 3-7
4-1 Welds Applicable to the Basic Joint Combinations 4-2
5-1 Low Pressure or Injector Type Torch 5-15
5-2 Balanced Pressure Type Torch 5-16
5-3 Oxyacetylene Cutting Information 5-21
5-4 Coating, Current, and Polarity Types Designated by the Fourth
Digit in the Electrode Classification Number 5-37
6-1 Preheating Temperatures 6-52
7-1 Physical Properties of Metals 7-2
7-2 Mechanical Properties of Metals 7-4
7-3 Hardness Conversion Table 7-8
7-4 Sunroary of Identification Tests of Metals 7-10
7-5 Summary of Spark Test 7-13
7-6 Approximate Hardness of Steel by the File Test 7-15
7-7 Carbon Content of Cast Iron and Steel 7-17
7-8 Standard Steel and Steel Alloy Number Designations 7-38
7-9 AISI-SAE Numerical Designation of Carbon and Alloy Steels 7-40
7-10 Standard Aluminum and Aluminum Alloy Number Designations 7-41
7-11 Letters Used to Identify Alloying Elements in Magnesium
Alloys 7-41
7-12 Composition of Magnesium Alloys 7-42
7-13 Copper and Copper Alloy Designation System 7-43
7-14 Electrode Numbers 7-55
7-15 Electrodes in the Army Supply System 7-55
7-16 Suggested Preheat Temperatures 7-56
7-17 Maximum Heat Inputs for T1 Steel 7-58
7-18 Maximum Heat Inputs for T1 Type A and Type B Steels 7-58
7-19 Welding Processes and Filler Metals for Cast Iron 7-60
xiiTC 9-237
7-20 Designation of Aluminum Alloy Groups 7-67
7-21 Welding Procedure Schedules for Gas Metal-Arc Welding (GMAW)
of Aluminum (MIG Welding) 7-71
7-22 Welding Procedure Schedules for AC-GTAW Welding of Aluminum
(TIG Welding) 7-74
7-23 Welding Procedure Schedules for DC-CTAW Welding of Aluminum
(TIG) Welding 7-75
7-24 Magnesium Weld Data 7-89
7-25 Magnesium Stress Relief Data 7-91
7-26 Welding Procedure Schedule for Gas Tungsten Arc Welding
(GTAW) of Magnesium (TIG Welding) 7-92
7-27 Welding Procedure Schedules for Gas Metal Arc Welding
(Q4AW) of Magnesium (MIG Welding) 7-93
7-28 Welding Procedure Schedule for Metal-Arc Welding (GMAW)
of Titanium (MIG Welding) 7-97
7-29 Welding Procedure Schedules for Gas Tungsten Arc Welding
(GTAW) Nickel Alloys (TIG Welding) 7-107
7-30 Welding Procedure Schedules for Gas Metal Arc Welding
(GMAW) Nickel Alloys (MIG Welding) 7-108
8-1 Mild Steel Electrode Wire Ccmposition for Submerged Arc
Welding 8-9
8-2 A.W.S. Filter Metal Specification and Welding Processes 8-23
10-1 Established Voltage Limits 10-30
10-2 Welding Position Capabilities 10-41
10-3 Base Metals Weldable by the Plasma Arc Process 10-42
10-4 Base Metal Thickness Range 10-42
10-5 Weld Procedure Schedule—Plasma Arc Welding—Manual
Application 10-47
10-6 Method of Applying Carbon Arc Processes 10-49
10-7 Welding Position Capabilities 10-49
10-8 Welding Procedure Schedule—Galvanized Steel—Braze Welding .... 10-52
10-9 Welding Procedure Schedule for Carbon Arc Welding Copper 10-52
10-10 Welding Current for Carbon Electrode Types 10-53
10-11 Welding current for carbon electrode (twin torch) 10-54
10-12 Mechanical Property ReguirAmenta of Carbon Steel Flux-Cored
Electrodes 10-74
10-13 Performance and Usability Characteristics of Carbon Steel Flux
Cored Electrodes 10-75
10-14 Chemical Composition Requirements of Carbon Steel Flux Cored
Electrodes 10-75
10-15 Mechanical Property Requirement of Low Alloy Flux-Cored
Electrodes 10-76
10-16 Impact Requirement for Low Alloy Flux-Cored Electrodes 10-77
10-17 Chemical Composition Requirements for Low Alloy Flux-Cored
Electrodes 10-78
10-18 Weld Metal Chemical Composition Requirements for Stainless
Steel Electrodes 10-80
10-19 Shielding 10-81
10-20 Reccrrmended Cable Sizes for Different Welding Currents and
Cable Lengths 10-82
10-21 Base Metals Weldable by the Submerged Arc Process 10-86
10-22 Base Metal Thickness Range 10-87
10-23 Welding Procedure Schedules for SAW 10-93
10-24 Typical Analysis and Mechanical Properties of Submerged Arc
Flux-Wire Ccmbinations 10-103
xiiiTC 9-237
LIST OF TABLES (cont)
Lumber Title Paae
10-25 Electrode Type—Size and Current Range 10-110
10-26 Air Carbon Arc Gouging Procedure Schedule 10-112
10-27 Base Metals Weldable by the Resistance Welding Process 10-115
11-1 Low Pressure of Injector Type Torch 11-5
11-2 Balanced Pressure Type Torch H-5
11-3 Heating Values of Fuel Gases * n-u
11“4 Oxy-Fuel Ratios Control Flame Condition 11-37
11-5 Approximate Conditions for Gas Welding of Aluminum 11-42
12-1 Recommended Welding Currents ” 12-5
12-2 Mechanical Properities of Sprayed Coatings 12-7
12-3 Minimum Thickness of As-Sprayed Coatings on Shafts 12-10
12-4 Shrinkage of Commonly Applied Sprayed Coatings 12-10
12-5 Welding Procedure Schedule for Oxyfuel Gas Cutting 12-18
12-6 Template Pattern Data ’ 12-57
12-7 Carmon Heat Treating Problems 12-73
12-8 Time Required in Case Hardening 12-79
12-9 Approximate Reheating Temperatures after Carburizing of SAE
Steel 12-80
12-10 Magnesium Spot Weld Data 12-84
12-11 Ccnmercially Pure Titanium Spot Weld Data 12-85
B-l Guide for Welding Automotive Equipment B-l
B-2 Guide for Oxyacetylene Welding B-l9
B-3 Guide for Electric Arc Welding B-23
C-l Troubleshooting c-l
D-1 Common Welding Equipment by Corrmercial and Government Entitv
Code (CAGEC) D-1
D-2 Metallizing Wire 0-4
D-3 Welding Electrodes D-4
D-4 Overlay, Welding and Cutting, Chamfering, and Heating
Electrodes d-8
D-5 Welding Rods d-9
D-6 Brazing Alloys D-12
D-7 Soldering Materials D-13
D-8 Fluxes, Welding, Brazing, and Soldering d-16
D-9 Carbon Blocks, Rods, and Paste D-17
E-l Temperature Ranges for Processing Metals E-l
E-2 Combustion Constants of Fuel Gases E-l
E-3 Melting Points of Metals and Alloys e-2
E-4 Temper Colors and Temperatures E-3
E-5 Heat Colors with Approximate Temperature E-3
E-6 Stub Steel Wire Gauges E-4
E-7 Standard Gauge Abbreviations E-5
E-8 Metal Gauge Comparisons E-6
E-9 Sheet Metal Gauge E-8
E-10 Elements and Related Chenical Symbols E-9
E-ll Decimal Equivalents of Fractions of an Inch E-10
E-12 Inches and Equivalents in Millimeter (1/64 Inch to 100 Inches) . E-ll
xivTC 9-237
WARNINGS
Cyanide and cyanide fumes are dangerous poisons. The cyaniding method of case
hardening requires expert supervision and adequate ventilation.
Oil or grease in the presence of oxygen will ignite violently, especially in an
enclosed pressurized area.
Do not substitute oxygen for compressed air in pneumatic tools. Do not use oxygen
to blow out pipe lines, test radiators, purge tanks or containers, or to "dust"
clothing.
Welding machine Model 301, AC/DC, Heliarc with inert gas attachment, NSN 3431-00-
235-4728, may cause electrical shock if not properly grounded. If one is being
used, contact Castolin Institute, 4462 York St., Denver, Colorado 80216 ATIN: Mr.
Lent.
The vapors fron sane chlorinated solvents (e.g. carbon tetrachloride,
trichloroethylene, and perchloroethylene) break down under the ultra-violet radia¬
tion of an electric arc and form a toxic gas. Avoid welding where such vapors are
present. These solvents vaporize easily and prolonged inhalation of the vapor can
be hazardous. These organic vapors should be removed fron the work area before
welding is begun.
Do not assume that a container that has held canbustibles is clean and safe until
proven so by proper tests. Do not weld in places where dust or other combustible
particles are suspended in air or where explosive vapors are present. Removal of
flammable material from vessels/containers may be done either by steaming out or
boiling.
The automotive exhaust method of cleaning should be conducted only in well ventilat¬
ed areas to ensure levels of toxic gases are kept below hazardous levels.
Welding polyurethane foam-filled parts can produce toxic gases. Welding should not
be attempted on parts filled with polyurethane foam. If repair of such parts by
welding is necessary, the foam must be removed fron the heat affected area,
including the residue, prior to welding.
Do not stand facing cylinder valve outlets of oxygen, acetylene, or other conpressed gases when opening them.
If it is necessary to blow out the acetylene hose, do it in a well ventilated
place, free of sparks, flame, or other sources of ignition.
aTC 9-237
WARNINGS (cont)
Purge both acetylene and oxygen lines (hoses) prior to igniting torch. Failure to
do thrs can cause serious injury to personnel and damage to the equipment.
Regulators with gas leakage between the regulator seat and the nozzle should be
repaired immediately to avoid damaged to other parts of the regulator or injnry to
personnel. With acetylene regulators, this leakage is particularly dangerous.
Acetylene at high pressure in the hose is an explosion hazard.
Defects.in oxyacetylene welding torches which are sources of gas leaks must be cor¬
rected immediately, as they may result in flashbacks, or backfires, with resultant
injury to the operator and/or damage to the welding apparatn^.
Damaged inlet
.
connection threads may cause fires by ignition of the leaking gas,
resulting in injury to the welding operator and/or damaged to the equipment.
Dry cleaning solvent and mineral spirits paint thinner are highly flammable. Do
not clean parts near an open flame or in a smoking area. Dry cleaning solvent and
mineral spirits paint thinner evaporate quickly and have a defatting effect on the
skin. When used without protective gloves, these chemicals may cause irritation or
cracking of the skin. Cleaning operations should be performed only in well venti¬
lated areas.
The acid solutions used to remove aluminum welding and brazing fluxes after welding
or brazing are toxic and highly corrosive. Goggles, rubber gloves, and rubber
aprons should be worn when handling the acids and solutions. Do not inhale fumes.
When spilled on the body or clothing, wash immediately with large quantities of
cold water.
Never pour water into acid when preparing solutions; instead, pour acid into wa¬
ter. Always mix acid and water slowly. These operations should only be performed
in well ventilated areas.
Precleaning and postcleaning acids used in magnesium welding and brazing are highly
toxic.and corrosive. Goggles, rubber gloves, and rubber aprons should be worn when
handling the acids and solutions. Do not inhale fumes and mists. When spilled on
the body or clothing, wash immediately with large quantities of cold water, and
seek medical attention. Do not pour water into acid when preparing solution; in¬
stead, pour acid into water. Always mix acid and water slowly. Cleaning opera¬
tions should be performed only in well ventilated areas.
If the electrode becomes frozen to the base metal during the process of starting
the arc, all work to free the electrode while the current is on must be done with
the eyes shielded.
bTC 9-237
The nitric acid used to preclean titanium for inert gas shielded arc welding is
highly toxic and corrosive. Goggles, rubber gloves, and rubber aprons should be
worn when handling the acid and the acid solution. Do not inhale gases and mists.
When spilled on the body or clothing, wash immediately with large quantities of
cold water, and seek medical help. Do not pour water into acid when preparing the
solution; instead, pour acid into water. Always mix acid and water slowly. Per¬
form cleaning operations only in well ventilated arpas ,
The caustic chemicals (including sodium hydride) used to preclean titaninn for
inert gas shielded arc welding are highly toxic and corrosive. Goggles, rubber
gloves, and rubber aprons should be worn when handling these chemicals. Do not
inhale gases or mists. When caustics are spilled on the body or clothing, wash
immediately with large quantities of cold water, and seek medical help. Special
care should be taken at all times to prevent any water frcm caning in contact with
the molten bath or any other large amount of sodium hydride, as this will cause the
evolution of highly explosive hydrogen gas.
When using weld backup tape, the weld must be allowed to cool for several minutes
before attempting to remove the tape from the workpiece.
Safety precautions must be exercised in underwater cutting and welding. Electrode
holder and cable must be insulated, current must be shut off when changing elec¬
trodes, and the diver should avoid contact between the electrode and grounded work.
In thermit welding, the mold must be thoroughly dried before the charge in the
crucible is ignited. When the charge has been ignited, the operator should stand a
safe distance away and should wear goggles. Painful burns may occur fron splashing
metal, upsetting of the crucible, breaking of the mold, or allowing the molten
metal to cone in contact with moisture in the mold.
Before welding on equipment painted with CARC paint, remove the paint from an area
larger than that which will be heated during welding.
Do not operate welding machines in an enclosed area unless the exhaust gases are
piped to the outside. Inhalation of exhaust fumes will result in serious illness
or death.
When filling the fuel tank, always provide a metal-to-metal contact between the
container and the fuel tank. This will prevent a spark frcm being generated as
fuel flews over the metallic surfaces.
Do not fill the fuel tanks while the engine is running. Fuel spilled on a hot
engine may explode and cause injury to personnel.
cTC 9-237
WARNINGS (cont)
Do not attempt any maintenance on the welding machine while it is in operation.
The voltage generated by it can cause injury or death.
Ensure that all welding machines are properly grounded. Failure to properly ground
welding machines could result in electrical shock.
Always use ear plugs. Diesel engines exceed a permissible decibel level. Failure
to observe this warning could result in a permanent hparing injury.
Always wear arc proof glasses or a welder's helmet when welding to prevent serious
eye burns or possible blindness.
Use only approved cleaning solvents to avoid the possibility of fire or poisoning.
Inert gas, metal-arc welding processes produce intense ultra-violet radiation which
can be harmful to the eyes and skin. Therefore, certain precautions must be ob¬
served to protect the operator frcm injury.
Skin must be completely covered. Leather gloves are recommended for hand protec¬
tion. Heavy, dark colored’clothing should be worn to prevent the radiation from
penetrating to the skin or reflecting onto the neck under the helmet. Lightweight
leather clothing is reccmmended because of its durability and resistance to deterio¬
ration from radiation. Cotton clothing will deteriorate rapidly when subjected to
ultra-violet radiation.
Adequate ventilation should be provided to remove fumes which are produced by weld¬
ing processes. American standard Z-49.1 on welding safety covers such ventilation
procedures. Highly toxic gases are formed when the vapors frcm halogenated sol¬
vents are subjected to ultra-violet radiation. Therefore, it is recarmended that
degreasers and other sources of these vapors should be located so that the vapors
cannot reach the welding operation.
Under no circumstances should acetylene cylinders be positioned or stored in other
than an upright position. Storage of the cylinder in a horizontal or reclining
position could create a hazardous condition.
Stand to the side of gas and oxygen cylinders when turning on the pressure release
valves. The cylinders contain extreme pressure. Injury could occur if a defective
flewmeter or pressure regulator valve ruptures when subjected to these pressures.
dTC 9-237
Ensure that all gages are removed from gas and oxygen cylinders before transport¬
ing. Failure to observe this warning could create a hazardous condition.
Wear head and eye protection, rubber gloves, boots, and aprons when handling steam,
hot water, and caustic solutions. When handling dry caustic soda or soda ash, wear
approved respiratory protective equipment, long sleeves, and gloves. Wear fire
resistant hand pads or gloves to handle hot drums.
Brazing filler metals containing cadmium may form poisonous fumes on heating- Do
not breathe fumes. Use only with adequate ventilation, such as fume collectors,
exhaust ventilators, or air-supplied respirators. See American National Standards
Institute Standard Z49.1-1973. If chest pain, cough, or fever develops after use,
call physician irrmediately.
Acetylene, stored in a free state under pressure greater than 15 psi (103.4 kPa),
can break down from heat or shock, and possible explode. Under pressure of 29.4
psi (203 kPa), acetylene becomes self-explosive, and a slight shock can cause it to
explode spontaneously.
Acetylene which may accumulate in a storage roan or in a confined space is a fire
and explosion hazard. All acetylene cylinders should be checked, using a soap
solution, for leakage at the valves and safety fuse plugs.
Do not stand facing cylinder valve outlets of oxygen, acetylene, or other conpressed gases when opening them.
Always have suitable fire extinguishing equipment at hand when doing and welding.
eTC 9-237
GLOSSARY
Section. I. GENERAL
G-l. GENERAL
This glossary of welding terms has been prepared to acquaint welding personnel with
nomenclatures and definitions of cannon terms related to welding and allied process¬
es, methods, techniques, and applications.
G-2. SCOPE
The welding ta-r-ms listed in section II of this chapter are those terms used to
dA^rrihA and define the standard nomenclatures and language used in this manual.
This glossary is a very inportant part of the manual and should be carefully stud¬
ied and regularly referred to for better understanding of cannon welding terms and
definitions. Terms and nomenclatures listed herein are grouped in alphabetical
order.
Section II. WELDING TERMS
G-3. WELDING TERMS
A
ACETONE; A flamnable, volatile liquid used in acetylene cylinders to dissolve and
stabilize acetylene under high pressure.
ACETYLENE: A highly combustible gas composed of carbon and hydrogen. Used as a
fuel gas in the oxyacetylene welding process.
ACTUAL THROAT: See THROAT OF FILLET WELD.
AIR-ACETYLENE: A low temperature flame produced by burning acetylene with air
instead of oxygen.
AIR-ARC CUTTING: An arc cutting process in which metals to be cut are melted by
the heat of the carbon arc.
at.toy? A mixture with metallic properties composed of two or more elements, of
which at least one is a metal.
ALTERNATING CURRENT: An electric current that reverses its direction at regularly
recurring intervals.
AMMETER: An instrument for measuring electrical current in amperes by an indicator
activated by the movement of a coil in a magnetic field or by the longitudinal
expansion of a wire carrying the current.
ANNEALING: A comprehensive term used to describe the heating and cooling cycle of
steel in the solid state. The term annealing usually implies relatively slow
cooling. In annealing, the temperature of the operation, the rate of heating and
cooling, and the time the metal is held at heat depend upon the ccmposition,
shape, and size of the steel product being treated, and the purpose of the treat¬
ment. The more important purposes for which steel is annealed are as follows:
to remove stresses; to induce softness; to alter ductility, toughness, electric,
magnetic, or other physical and mechanical properties; to change the crystalline
structure; to remove gases; and to produce a definite microstructure.
ARC BLOW: The deflection of an electric arc from its normal path because of magnet¬
ic forces.
ARC BRAZING: A brazing process wherein the heat is obtained from an electric arcTC 9-237
G-3. WELDING TERMS (cont)
A (cont)
formed between the base metal and an electrode, or between two electrodes.
ARC CUTTING: A group of cutting processes in which the cutting of metals is accom¬
plished by melting with the heat of an arc between the electrode and the base met¬
al. See CARBON-ARC CUTTING, METAL-ARC CUTTING, ARC-OXYGEN CUTTING, AND AIR-ARC
CUTTING•
ARC LENGTH: The distance between the tip of the electrode and the weld puddle..
ARC-OXYGEN CUTTING: An oxygen-cutting process used to sever metals by a chemical
reaction of oxygen with a base metal at elevated temperatures.
ARC VOLTAGE: The voltage across the welding arc.
ARC WELDING: A group of welding processes in which fusion is obtained by heating
with an electric arc or arcs, with or without the use of filler metal.
AS WELDED: The condition of weld metal, welded joints, and weldments after welding
and prior to any subsequent thermal, mechanical, or chemical treatments.
ATOMIC HYDROGEN WELDING: An arc welding process in which fusion is obtained by
Haa-f-ing with an arc maintained between two metal electrodes in an atmosphere of
hyd-mgen. Pressure and/or filler metal may or may not be used.
AUSTENITE: The non-magnetic form of iron characterized by a face-centered cubic,
lattice crystal structure. It is produced by heating steel above the upper criti¬
cal temperature and has a high solid solubility for carbon and alloying elements.
AXIS OF A WET.Dr A line through the length of a weld, perpendicular to a cross
section at its center of gravity.
B
BACK FIRE: The iranentary burning back of a flame into the tip, followed by a snap
or pop, then immediate reappearance or burning out of the flame.
BACK PASS: A pass made to deposit a back weld.
BACK UP: In flash and upset welding, a locator used to transmit all or a portion
of the upsetting force to the workpieces.
BACK WELD: A weld deposited at the back of a single groove weld.
BACKHAND wet,DTNG: A welding technique in which the flame is directed towards the
completed weld.
BACKING STRIP: A piece of material used to retain molten metal at the root of the
weld and/or increase the thermal capacity of the joint so as to prevent excessive
warping of the base metal.
BACKING wetd: A weld bead applied to the root of a single groove joint to assure
complete root penetration.
BACKSTEP: A sequence in which weld bead increments are deposited in a direction
opposite to the direction of progress.
BARE ELECTRODE: An arc welding electrode that has no coating other than that inci¬
dental to the drawing of the wire.
BARE METAL-ARC WELDING: An arc welding process in which fusion is obtained by
h^abing with an unshielded arc between a bare or lightly coated electrode and the
work. Pressure is not used and filler metal is obtained from the electrode.
BASE METAL: The metal to be welded or cut. In alloys, it is the metal present in
the largest proportion.
BEAD WELD: A type of weld composed of one or more string or weave beads deposited
on an unbroken surface.
BEADING: See STRING BEAD WELDING and WEAVE BEAD.
revet, ANGLE: The angle formed between the prepared edge of a member and a plane
perpendicular to the surface of the member.TC 9-237
BLACKSMITH WELDING: See FORGE WELDING.
BLOCK BRAZING: A brazing process in which bonding is produced by the heat obtained
frcm heated blocks applied to the parts to be joined and by a nonferrous filler
metal having a melting point above 800 °F (427 °C), but below that of the base
metal. The filler metal is distributed in the joint by capillary attraction.
BLOCK SEQUENCE: A building up sequence of continuous multipass welds in which sepa¬
rated lengths of the weld are completely or partially built up before intervening
lengths are deposited. See BUILDUP SEQUENCE.
BLOW HOLE: See GAS POCKET.
BOND: The junction of the welding metal and the base metal.
BOXING: The operation of continuing a fillet weld around a comer of a member as
an extension of the principal weld.
BRAZING: A group of welding processes in which a groove, fillet, lap, or flange
joint is bonded by using a nonferrous filler metal having a -melting point above
800 F (427 °C), but below that of the base metals. Filler metal is distributed
in the joint by capillary attraction.
BRAZE WELDING: A method of welding by using a filler metal that liquifies above
450 °C (842 °F) and below the solid state of the base metals. Unlike brazing, in
braze welding, the filler metal is not distributed in the joint by capillary
action.
BRIDGING: A welding defect caused by poor penetration. A void at the root of the
weld is spanned by weld metal.
BUCKLING: Distortion caused by the heat of a welding process.
BUILDUP SEQUENCE: The order in which the weld beads of a multipass weld are depos¬
ited with respect to the cross section of a joint. See BLOCK SEQUENCE.
BUTT JOINT: A joint between two workpieces in such a manner that the weld joining
the parts is between the surface planes of both of the pieces joined.
BUTT WELD: A weld in a butt joint.
BUTTER WELD: A weld composed of one or more string or weave beads laid down on an
unbroken surface to obtain desired properties or dimensions.
C
CAPILLARY ATTRACTION: The phenomenon by which adhesion between the molten filler
metal and the base metals, together with surface tension of the molten filler met¬
al, causes distribution of the filler metal between the properly fitted surfaces
of the joint to be brazed.
CARBIDE PRECIPITATION: A condition occurring in austenitic stainless steel which
contains carbon in a supersaturated solid solution. This condition is unstable.
Agitation of the steel during welding causes the excess carbon in solution to pre¬
cipitate. This effect is also called weld decay.
CARBON—ARC CUTTING: A process of cutting metals with the heat of an arc between a
carbon electrode and the work.
CARBON—ARC WELDING: A welding process in which fusion is produced by an arc be¬
tween a carbon electrode and the work. Pressure and/or filler metal and/or
shielding may or may not be used.
CARBURIZING FLAME: An oxyacetylene flame in which there is an excess of acety¬
lene. Also called excess acetylene or reducing flame.
CASCADE SEQUENCE: Subsequent beads are stopped short of a previous bead, giving a
cascade effect.
CASE HARDENING: A process of surface hardening involving a change in the conposition of the outer layer of an iron base alloy by inward diffusion frcm a gas or
liquid, followed by appropriate thermal treatment. Typical hardening processes
are carburizing, cyaniding, carbonitriding, and nitriding.
CHAIN INTERMITTENT FILLET WELDS: Two lines of intermittent fillet welds in a T orTC 9-237
G-3. WELDING TERMS (cont)
C (cont)
lap joint in which the welds in one line are approximately opposite those in the
other line.
CHAMFERING: The preparation of a welding contour, other than for a square groove
weld, on the edge of a joint member.
COALESCENCE: The uniting or fusing of metals upon heating.
COATED ELECTRODE: An electrode having a flux applied externally by dipping, spraypainting, or other similar methods. Upon burning, the coat produces a gas
which envelopes the arc.
CQMMUTATORY CONTROLLED WELDING: The making of a number of spot or projection welds
in which several electrodes, in simultaneous contact with the work, progressively
function under the control of an electrical ccmnutating device.
COMPOSITE ELECTRODE: A filler metal electrode used in arc welding, of
more than one metal component combined mechanically. It may or may not include
materials that improve the properties of the weld, or stabilize the arc.
COMPOSITE JOINT: A joint in which both a thermal and mechanical process are used
to unite the base metal parts.
CONCAVITY: The maximum perpendicular distance from the face of a concave fillet
weld to a line joining the toes.
CONCURRENT HEATING: Supplemental heat applied to a structure during the course of
welding.
CONE: The conical part of a gas flame next to the orifice of the tip.
CONSUMABLE INSERT: Preplaced filler metal which is completely fused into the root
of the joint and becomes part of the weld.
CONVEXITY: The maximum perpendicular distance from the face of a convex fillet
weld to a line joining the toes.
CORNER JOINT: A joint between two members located approximately at right angles to
each other in the form of an L.
COVER GLASS: A clear glass used in goggles, hand shields, and helmets to protect
the filter glass fran spattering material.
COVERED ELECTRODE: A metal electrode with a covering material which stabilizes the
arc and inproves the properties of the welding metal. The material may be an
external wrapping of paper, asbestos, and other materials or a flux covering.
CRACK: A fracture type discontinuity characterized by a sharp tip and high ratio
of length and width to opening displacement.
CRATER: A depression at the termination of an arc weld.
CRITICAL TEMPERATURE: The transition temperature of a substance from one crystal¬
line form to another.
CURRENT DENSITY: Amperes per square inch of the electrode cross sectional arpa ,
CUTTING TIP: A gas torch tip especially adapted for cutting.
CUTTING TORCH: A device used in gas cutting for controlling the gases used for
preheating and the oxygen used for cutting the metal.
CYLINDER: A portable cylindrical container used for transportation and storage of
a compressed gas.
D
DEI‘ECT: A discontinuity or discontinuities which, by nature or accumulated effect
(for example, total crack length), render a part or product unable to meet mini¬
mum applicable acceptance standards or specifications. This term designates
rejectability.
G-4TC 9-237
DEPOSITED METAL: Filler metal that has been added during a welding operation.
DEPOSITION EFFICIENCY: The ratio of the weight of deposited metal to the net
weight of electrodes consumed, exclusive of stubs.
DEPTH OF FUSION: The distance from the original surface of the base metal to that
point at which fusion ceases in a welding operation.
DIE:
a. Resistance Welding. A member, usually shaped to the work contour, used to
clamp the parts being welded and conduct the welding current.
b. Forge Weld-ing. A device used in forge welding primarily to form the work
while hot and apply the necessary pressure.
DIE WELDING: A forge welding process in which fusion is produced by heating in a
furnace and by applying pressure by means of dies.
DIP BRAZING: A brazing process in which bonding is produced by heating in a molten
chemical or metal bath and by using a nonferrous filler metal having a melting
point above 800 °F (427 °C), but below that of the base metals. The filler metal
is distributed in the joint by capillary attraction. When a metal bath is used,
the bath provides the filler metal.
DIRECT CURRENT ELECTRODE NEGATIVE (DCEN): The arrangement of direct current arc
xvplding leads in which the work is the positive pole and the electrode is the
negative pole of the welding arc.
DIRECT CURRENT ELECTRODE POSITIVE (DCEP): The arrangement of direct current arc
weld i ng leads in which the work is the negative pole and the electrode is the
positive pole of the welding arc.
DISCONTINUITY: An interruption of the typical structure of a weldment, such as
lack of homogeneity in the mechanical, metallurgical, or physical characteristics
of the material or weldment. A discontinuity is not necessarily a defect.
DRAG: The horizontal distance between the point of entrance and the point of exit
of a cutting oxygen stream.
DUCTILITY: The property of a metal which allows it to be permanently deformed, in
tension, before final rupture. Ductility is canmonly evaluated by tensile test¬
ing in which the amount of elongation and the reduction of area of the broken
specimen, as compared to the original test specimen, are measured and calculated.
DUTY CYCLE: The percentage of time during an arbitrary test period, usually 10
minutes, during which a power supply can be operated at its rated output without
overloading.
E
EDGE JOINT: A joint between the edges of two or more parallel or nearly parallel
members.
. . .
EDGE PREPARATION: The contour prepared on the edge of a joint member for welding.
Ehl'ECTIVE LENGTH OF WELD: The length of weld throughout which the correctly propor¬
tioned cross section exits.
ELECTRODE:
a. Metal-Arc. Filler metal in the form of a wire or rod, whether bare or cov¬
ered, through which current is conducted between the electrode holder and the arc.
b. Carhnn-Art-. A carbon or graphite rod through which current is conducted
between the electrode holder and the arc.
c. Atomic Hydrogen. One of the two tungsten rods between the points of which
the arc is maintained.
d. Electrolytic Oxygen-Hydrogen Generation. The conductors by which current
enters and leaves the water, which is decomposed by the passage of the current.
e. Resistance Welding. The part or parts of a resistance welding machine
through which the welding current and the pressure are applied directly to the work.
G-5TC 9-237
G-3. WELDING TERMS (cont)
E (cont)
ELECTRODE FORCE:
a. Dynamic. In spot, seam, and projection welding, the force (pounds) between
the electrodes during the actual welding cycle.
b. Theoretical. In spot, seam, and projection welding, the force, neglecting
friction and inertia, available at the electrodes of a resistance welding machine
by virtue of the initial force application and the theoretical mechanical advantage
of the system.
c. Static. In spot, seam, and projection welding, the force between the elec¬
trodes under welding conditions, but with no current flowing and no movement in the
welding machine.
ELECTRODE HOLDER: A device used for mechanically holding the electrode and conduct¬
ing current to it.
ELECTRODE SKID: The sliding of an electrode along the surface of the work during
spot, seam, or projection welding.
EMBOSSMENT: A rise or protrusion from the surface of a metal.
ETCHING: A process of preparing metallic specimens and welds for macrographic or
micrographic examination.
F
FACE REINFORCEMENT: Reinforcement of weld at the side of the joint from which
welding was done.
FACE OF WELD: The exposed surface of a weld, made by an arc or gas welding pro¬
cess, on the side frcm which welding was done.
FAYING SURFACE: That surface of a member that is in contact with another member to
which it is joined.
FERRITE: The virtually pure form of iron existing below the lower critical tempera¬
ture and characterized by a body-centered cubic lattice crystal structure. It is
magnetic and has very slight solid solubility for carbon.
FILLER METAL: Metal to be added in making a weld.
FILLET WET.D: A weld of approximately triangular cross section, as used in a lap
joint, joining two surfaces at approximately right angles to each other.
FILTER GLASS: A colored glass used in goggles, helmets, and shields to exclude
harmful light rays.
FLAME CUTTING: See OXYGEN CUTTING.
FLAME GOUGING: See OXYGEN GOUGING.
FLAME HARDENING: A method for hardening a steel surface by heating with a gas
flame followed by a rapid quench.
FLAME SOFTENING: A method for softening steel by heating with a gas flame followed
by slow cooling.
FLASH: Metal and oxide expelled frcm a joint made by a resistance welding process.
FLASH WRIT)TNG: A resistance welding process in which fusion is produced, simultane¬
ously over the entire area of abutting surfaces, by the heat obtainedfrcm resis¬
tance to the flew of current between two surfaces and by the application of pres¬
sure after heating is substantially completed. Flashing is accompanied by expul¬
sion of metal from the joint.
FLASHBACK: The burning of gases within the torch or beyond the torch in the hose,
usually with a shrill, hissing sound.
FLAT POSITION: The position in which welding is performed frcm the upper side of
the joint and the face of the weld is approximately horizontal.
FLOW BRA2ING: A process in which bonding is produced by heating with a molten
G-6TC 9-237
nonferrous filler metal poured over the joint until the brazing temperature is
Attained. The filler metal is distributed in the joint by capillary attraction.
See BRAZING.
FLOW welding; A process in which fusion is produced by heating with molten filler
metal poured over the surfaces to be welded until the welding temperature is at¬
tained and the required filler metal has been added. The filler metal is not dis¬
tributed in the joint by capillary attraction.
FLUX: A cleaning agent used to dissolve oxides, release trapped gases and slag,
and to cleanse metals for welding, soldering, and brazing.
FOREHAND WELDING: A gas welding technique in which the flame is directed against
the base metal ahead of the completed weld.
FORGE WELDING: A group of welding processes in which fusion is produceci by heating
in a forge or furnace and applying pressure or blows.
free BEND TEST: A method of testing weld specimens without the use of a guide.
FTm,FILLET WELD: A fillet weld whose size is equal to the thickness of the thin¬
ner member joined.
FURNACE BRAZING: A process in which bonding is produced by the furnace heat and a
nonferrous filler metal having a melting point above 800 °F (427 C), but below
that of the base metals. The filler metal is distributed in the joint by capil¬
lary attraction.
FUSION: A thorough and complete mixing between the two edges of the base metal to
be joined or between the base metal and the filler metal added during welding.
FUSION ZONE (filler PENETRATION): The area of base metal melted as determined on
the cross section of a weld.
G
GAS CARBON-ARC WELDING; An arc welding process in which fusion is produced by
heating with an electric arc between a carbon electrode and the work. Shielding
is obtained frcm an inert gas such as helium or argon. Pressure and/or filler
metal may or may not be used.
GAS METAL-ARC (MIG) WELDTNG (GMAW): An arc welding process in which fusion is
produced by heating with an electric arc between a metal electrode and the work.
Shielding is obtained frcm an inert gas such as helium or argon. Pressure and/or
filler metal may or may not be used.
GAS POCKET: A weld cavity caused by the trapping of gases released by the metal
when cooling.
GAS TUNGSTEN-ARC (TIG) WELDING (GTAW): An arc welding process in which fusion is
produced by heating with an electric arc between a tungsten electrode and the
work while an inert gas flows around the weld area to prevent oxidation. No flux
is used.
GAS WELDING: A process in which the welding heat is obtained frcm a gas flame.
GLOBULAR TRANSFER (ARC WELDING): A type of metal transfer in which molten filler
metal is transferred across the arc in large droplets.
GOGGLES; A device with colored lenses which protect the eyes frcm harmful radia¬
tion during welding and cutting operations.
GROOVE: The opening provided between two members to be joined by a groove weld.
GROOVE ANGLE: The total included angle of the groove between parts to be joined by
a groove weld.
GROOVE FACE: That surface of a member included in the groove.
GROOVE RADIUS: The radius of a J or U groove.
GROOVE WELD: A weld made by depositing filler metal in a groove between two mem¬
bers to be joined.
GROUND CONNECTION: The connection of the work lead to the work.
G-7TC 9-237
G-3. WELDING TERMS (cont)
G (cont)
GROUND LEAD: See WORK LEAD.
GUIDED BEND TEST: A bending test in which the test specimen is bent to a definite
shane _ bv means of a iic.
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