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Electric Arc Welding



By



E. WANAMAKER

ELECTRICAL ENGINEER, CHICAGO, ROCK. ISLAND &
PACIFIC RAILROAD

and
H. R. PENNINGTON

SUPERVISOR OF ELECTRICAL EQUIPMENT AND WELD-
ING, CHICAGO, ROCK ISLAND & PACIFIC
RAILROAD



Published and Printed in U. S. A. by
SIMMONS-BOARDMAN PUBLISHING COMPANY

WOOLWORTH BUILDING, NEW YORK

CHICAGO WASHINGTON CLEVELAND

CINCINNATI NEW ORLEANS

LONDON



COPYRIGHT,

SlMMONS-BoARDMAN PUBLISHING COMPANY

1921



Press of

J. J. Little & Ives Company
New York, U. S. A.



PREFACE

The authors of this work have not attempted to cover the
electric welding art in its broadest sense. The book is confined
almost exclusively to autogenous electric arc welding.

The phenomena of the welding arc, and the metallurgy of
welding, are in such a state of development that the authors' in-
formation has been limited to the research which has come under
their observation. Many phases of these subjects have been left,
therefore, to specialists more adequately equipped both as to
electric and metallurgical data as well as laboratory apparatus.
The effort has been made to present information that is most in
demand for practical purposes.

The material is conveniently and logically arranged for ready
reference. A large amount of practical information on many
phases of the application of the art has- been incorporated ; for
instance, descriptions of welding systems and their installation,
phenomena of the metallic and carbon welding arc, training of
operators, sequence of metal disposition for various types of
joints and building up operations, electrode materials used, weld-
ability of various metals, weld composition, thermal disturbances
of parts affected by the welding process, physical properties of
completed welds, efficiency of welding equipments expressed in
pounds of metal used or deposited per kilowatt hours, welding
cost, etc.

It is desired to lay particular stress on the fact that a very
small percentage of the possibilities and advantages of arc weld-
ing, from an industrial standpoint, are being made use of at the
present time, and if this work will result in a broader application
of the art, as well as further and more extensive research, the
authors will feel well repaid for their humble efforts.

The book is based largely on an extensive series of articles by

iii



/ : 73729



IV



PREFACE



the authors which was published in The Railway Electrical En~
gineer. Such parts of these articles as are used here, however,
have been thoroughly revised and brought up-to-date.

THE AUTHORS.
Chicago, 111.



CONTENTS



PAGE

PREFACE iii

SECTION I

History of the Evolution of Welding Processes Smith or Forge
Welding, Resistance Welding, Thermit Welding, Ox-acetylene
Welding, and Electric Arc Welding I

SECTION II

Equipment for Electric Arc Welding Types Used, Operating

Characteristics and Circuits 8

SECTION III

Installation of Arc Welding Equipment Welding Accessories
Portable and Stationary Equipment Eye and Body Protection
Cleaning Devices, etc 34

SECTION IV

Electric Arc Welding Principles Circuit Polarity Arc Heat Arc
Temperature Arc Current and Potential Metal Transfer, etc. . 54

SECTION V

Training of Operators Practice Exercises Sequence of Metal

Deposition Fusion Penetration Expansion and Contraction . 69

SECTION VI

Carbon Arc Welding Metal Cutting by Electric Arc and by Oxida-
tion 97

SECTION VII
Electrode Materials Composition Specifications, etc 107

SECTION VIII

Preparation of Work for Electric Arc Welding Various Designs of

Welds Types of Joints, etc 125

v



vi CONTENTS

SECTION IX

PAGE

Iron and Steel, and the Welding of Each Non-ferrous Metals and
Their Weldability 142

SECTION X

Application of Arc Welding to Railroads and Structural Engineer-
ing . . 175

SECTION XI

Miscellaneous Notes and Arc Welding Data Composition of Weld
. Thermal Disturbances Physical Qualities Cost, etc. . . . 230



LIST OF ILLUSTRATIONS

FIG. NO. PAGE

1. Generator Control and Auxiliary Panel Circuits with One

Welding Connection on Each 9

2. Generator Control and Auxiliary Panels 10

2-A_ Electric Arc Welding with Fixed Resistors n

3. Constant Current System Circuit and Characteristic Curves . 13

4. Oscillograms Showing Effect with and without Reactor in

Circuit 15

5. Control Panel and Welding Generator with Motor and Reactor 16

6. Circuits and Characteristic Curves of a Variable Voltage Type

Welder . 17

7. Circuits and Characteristic Curves of Another Variable Voltage

Type Welder " 18

8. A Self-Regulating Motor-Generator Welder 19

9. Characteristic Curves and Circuits for a Self-Regulating Motor-

Generator Arc Welder 20

9-A. Illustrating How Regulation is Produced by Shifting the

Line of Maximum Potential Difference 21

9-B. Modification of Design Shown in Fig. 9-A 22

9-C. Another Type of Welding Generator in Which Regulation

is Mainly Produced by the Armature 23

9-D. Characteristics of Generator Shown in Fig. 9-C .... 24
9-E Welding Generator with Inter-Connected, Separate and Self-
Excited Shunt Field 25

10. A Direct Current Welding Converter 27

11. Circuit for a Direct Current Welding Converter 28

12. Constant Energy Arc Welding Set, One-Man Portable Outfit,

Norfolk Navy Yard f 29

13. Circuits for Equipment Illustrated in Fig. 12 30

14. Alternating Current Equipment 32

15. Layout for Portable Arc Welding Equipment in Roundhouses 36

16. A Portable Type of Arc Welding Equipment 37

17. A Gas Engine-Driven Electric Welding Equipment .... 38

18. Locomotive Repair Shop Floor Plan 40-41

19. Single Operator Stationary Type Welder Mounted on a Column 43

20. Helmet and Hand Shields for Welding Operators .... 46

21. Operator Equipped with Helmet, Apron, Gauntlet Gloves and

Heavy Closely-Woven Shirt 46

22. Booth for Welding Small Miscellaneous Parts 47

23. A Portable Screen for Welding Operator . 48

24. A Metallic Electrode Arc Welding Holder 49

vii



viii LIST OF ILLUSTRATIONS

FIG. NO. PAGE

25. Details of Fig. 24 50

26. An Electrode Holder for Carbon Arc Welding 51

27. Small Sand Blast and Roughing Tool 52

28. Sketch Showing Polarity of Welding Electrode and of Work 54

29. Comparison Between Long and Short Arcs 64

30. Penetration 66

30-A. Overlap 66

31. Instructions for Starting and Stopping Individual Type Equip-

ment 71

32. Diagram for Beginner's Use Showing How Connections Should

Be Made 72

33. Methods of Striking an Arc . . 73

34-39. Practice Exercises for Training Operators to Hold an Arc

and Follow a Given Course 78

40-43. Adding Metal to Joints, Showing Course of Electrode and

Method of Building up Metal 80

43-A. Fused Zones, Stressed in Parallel and in Series .... 84

44. Work Marked off in Sections, Illustrating Methods of Back

Step Welding 93

45. Strains Produced by Cooling of Metal in the Weld .... 94

46. Adapter Used for Low Current Valves and Intermittent Welding 97

47. Correct Position of Graphite Electrode and Filler Rod ... 98

48. Edges Joined by Melting Together, without Use of Filler Rod 99

49. Ragged Edges Produced on Plate Material when Cut by

Carbon Arc 102

50. Test Pieces for Tensile, Cold Bend and Fatigue Specimens . 121

51. Test Pieces for Impact Specimens 122

52. Current Carrying Capacity of Welding Carbons . . . . 124
53-57- Parts to be Joined, Showing Effect of Expansion and Con-
traction 127

58. Welds Showing Relation of Parts and Spacing 129

59. Showing Free Space Necessary for Best Welding Results . . 130

60. Method Used Where No Free Space Can Be Allowed at Bottom 130

61. Method of Beveling 131

62. Reinforced Weld Section .131

63. Types of Joints 132

64. Position of Welds . . '"Y .... 134

65. Kinds of Welds . . . . . 135

66. Types of Welds Reinforced, Flush and Concave 137

67-70. Preparing Cylinders and Vessels for Welding . ... . 140
71-76. Preparation of Longitudinal Seams, Pipes and Tubes for

Welding 140

77. Showing Three Kinds of Metal in Completed Weld . . .' . 145

78. Broken Cast Iron Locomotive Cylinder Showing Fracture

Partially Welded 146

79. Method of Welding Used to Avoid Need of Machining Through

Heat-Affected Zone 147



LIST OF ILLUSTRATIONS ix

FIG. NO. PAGE

80. Fractured Blades Welded to Cast Steel Turbine by Electric

Arc Welding 161

81. Shaft for Excitor Turbine Welded by Metallic Arc Welding

Apparatus 162

82. Sections of Piston Rod Built up by Metallic Arc Showing

Effect of Localized Heat and the Result of Annealing . . 165
82-A. Crank Pin; Metal Added with Electric Arc without Pre-
heating 169

82-B. Crank Pin; Metal Added with Electric Arc after Preheating

in Blacksmith Furnace 170

82-C. Crank Pin ; Metal Added with Electric Arc after Preheating

with Arc 171

82-D. Piston Rod ; Preheated and Metal Added with Oxy-Acetylene 172

82-E. Piston Rod; Metal Added with Oxy-Acetylene, no Preheating 173

83. Preparation of Door and Flue Sheet, Crown Seams and Side

Seams for Arc Welding New Firebox 176

84. Method of Procedure in Welding the Four Vertical Seams

on a Firebox *. 177

85. Numerical Order and Direction of Welds .177

86. Side Sheet Joints Welded with Electric Arc 178

87. Joint of Crown Sheet Welded with Electric Arc .... 179

88. Two-Syphon Application to Firebox with Combustion Chamber 180

89. Diaphragm Plate Welded in by Means of Electric Arc . . . 180

90. Proper and Improper Reinforcement 181

' 91. Two types of Door Hole Flange Welds . 181

92. Arc Welded Seam across Outside Door Sheet 182

93. Welding Edges of the Sheet to Mud Ring . . .... 183

94. Flue Sheet Hole Countersunk with Flue Set Flush .... 183

95. Fillet Weld Flue, Extended ........ . . . . . 183

96. Procedure in Welding Beaded and Expanded Flues .... 184

97. Beaded and Expanded Flues Welded by Electric Arc ... 187

98. Section of Beaded and Expanded Flues Welded by Electric Arc

with and without Copper Ferrule 187

99. Showing Where Cuts Are to be Made When Repairing Various

Parts of Firebox 188

100. Showing Where Cuts Are to be Made When Repairing Front

and Back of Flue Sheets 189

101. Patch or Flue Sheet and around Arch Tube Welded with

Electric Arc 190

102. Front Flue Sheet Joints Welded with Electric Arc ... 191

103. Procedure in Welding Side Sheets 192

104. Procedure in Welding Front and Back Flue Sheets ... 1.93

105. A Crown Patch Weld 194

106. Welding Corner Patches 194

107. Procedure in Welding Crack in Knuckle of Back Flue Sheet 195

108. Repairing Fractures between Rivet Holes at Mud Ring . . 195

109. Repairing Fractures by Means of Disc 196



x LIST OF ILLUSTRATIONS

FIG. NO. PAGE

no. Procedure in Applying New Door Hole Collar 197

111-113. Repairing Corroded or Over-Size Washout Plugs . . . 197

114. Repairing an Old Riveted Seam 197

115. Sleeve of a Flexible Staybolt Welded to Sheet 197

116. Hatch Cover Corners Welded in the Navy Yard 199

117. Spray Shield for a Gun, Constructed by Electric Welding . . 200

118. Rudder for a Lake Boat, Repaired by Electric Welding . . 201

119. Bracket Constructed and Joined to Column by Metallic Arc

Welding 202

120. Peak of Truss Showing Members Joined by Electric Arc

Welding 203

121. Members of the Roof Frame Joined by Electric Arc Welding 204

122. Method of Welding Horizontal Locomotive Frame Member

Double "V," Side Position 205

123. Filling Pieces for Five- and Six-Inch Frames 206

124-129. Method when Work Can Be Done from Both Sides of

Frame . . . , > . . . ' \ . 207

130. Method of Welding Vertical Member of Frame Pedestal

Double "V," Side Position 208

I 3i- I 35- Procedure When Work Cannot Be Done from Either Side

of Frame 208

136. A Completed Weld Using Filler Plates in Locomotive Frame 209

137. Building up Flanges of Wheels by Arc Welding Process . .211

138. Working Standards for Reclaiming Axles by Electric Arc Weld-

ing 212

139. Fracture Prepared for Electric Welding . . . . . . . . 213

140. Electric Welded Coupler . . ..... ... , . . 213

141. A Triple Weld in Face of Coupler 214

142. An Electric Welded Shank ' . . . . 214

143. Built-up Coupler Shank 215

144. Method of Applying Cast Steel Shims to Convert 6^/2 in. Coupler

Shank to 9^ in 216

145. Fractured Car Bolster Prepared for Electric Welding . . . 217

146. Welded Fracture 217

147. How Reinforcing Plates Are Applied 217

148. How Reinforcing Plates Are Applied 218

149. Repairing Cast Steel Side Truck Frame by Metallic Arc

Welding . . . . .219

150. Fractured Cast Iron Cylinder of a Mikado Type Locomotive

Prepared for Arc Welding 224

151. Welded Cast Iron Cylinder of Mikado Type Locomotive . . 225

152. Journal Box Completely Built Up 226

153. Gear Casing Built Up 226

154. Wheels Cast in Separate Parts Assembled by Arc Welding

Process (See Fig. 155) 227

155. Wheels Cast in Separate Parts Assembled by Arc Welding

Process (See Fig. 154) 227



LIST OF ILLUSTRATIONS xi

FIG. NO. PAGE

156. Truck Frame and Bolster Built up by Arc Welding Process 228

157. Truck Frame and Bolster Built up by Arc Welding Process 228

158. Typical Structure of Plate Just Below Weld (Magnified) . . 234
159- Typical Structure of Plate a Slight Distance Below Weld

(Magnified) 235

160. Typical Structure of Plate Beyond Influence of Weld (Mag-

nified) 235

161. Average View of Deposited Metal of Weld (Magnified) . . 236

162. Streaks of Alumina Inclusions in the Steel Plate (Magnified) 237

163. Typical Structure of Deposited Metal of the Weld After An-

nealing at 900 C. for Four Hours Showing Oxide and
Nitride 238

164. Structure of Harrow Zone Between Weld and Plate After

Annealing as Above, Showing Pearlite and Nitride in
Ferrite 238

165. Typical Structure of Steel Plate Below Weld After Annealing

as Above, Showing Pearlite and Coarse Ferrite without
Nitride : .239

166. Typical Structure of Deposited Metal of the Weld as Received,

without Annealing, Showing Round Gray Oxide Spots and
Pale Angular Nitride Crystals 240

167. Typical Structure of Deposited Metal of Weld After Anneal-

ing at 500 C. for Two Hours, Showing Nitride Needles
Darkened by the Etching and Round Oxide Dots Unchanged 241



ELECTRIC ARC WELDING



EVOLUTION OF WELDING PROCESSES

There are several methods of joining metals other than by
means of mechanical fastenings, such as bolts, clamps, rivets,
hinges, etc. The first form of jointure known to man, other than
the above-mentioned, was fire or forge welding performed by a
smith, the operation consisting essentially of heating the parts to
be welded to the proper temperature and perfecting a union by
applying pressure by means of hammer and anvil.

As pressure welding was limited in its application man en-
deavored to find some other way to join metals, or to make addi-
tions of metal to other metal, without the use of pressure. He
was eventually successful in this endeavor and welding without
pressure came to be known as autogenous welding, so called be-
cause of its self- or auto-generation ; i. e., it is self-produced by
the application of intense heat without any physical process of
compression or hammering.

We, therefore, have two general forms of welding one requir-
ing external application of pressure to complete the weld, and one
in which the weld is completed without the external application of
pressure. In the first form the union is secured by using a com-
paratively low heat and high pressure. In the second the union is
secured by a relatively high temperature without the aid of any
external pressure. It will be seen, in view of the fact that weld-
ing requires actual fusion of the metals joined or added, that
the process differs inherently from those methods of joining
metals known as brazing or soldering, in which cold surfaces are
united by the interposition of a fused metallic cementing material,
which is an example of adhesion rather than cohesion.



WELDING



Pressure Welding. The conditions for successful smith or
forge welding, which is a form of pressure welding, may be
summed up as clean metallic surfaces in contact, with a suitable
temperature and rapid closing of the joints. All the variations in
the forms of welds are due either to differences in shapes of
material or to the different practices of different craftsmen.

The typical weld is the scarf; the joint is made diagonally to
give a long contact at the point of union. Abutting faces are
made slightly convex. The object is to allow any scale or dirt
to be forced out which if allowed to become embedded in the joint
would impair its union. It is important to have the proper tem-
perature or else the metal will become badly oxidized (burnt)
and will not adhere. This is especially true in the case of steel
welding.

Resistance Welding. Resistance welding is another form
of pressure welding in which an electric current is made use
of to produce the welding heat. There are two general forms of
resistance welding; namely, butt and spot, the name in each case
being thoroughly indicative of the service for which each form is
particularly adapted.

Butt welding is accomplished by having the surfaces, or parts
of the metal to be united, fitted approximately to each other.
Clamps of suitable design, generally made of copper, are then
attached in as close proximity to the weld as is practicable and in
such a way as to permit the desired amount of current to pass
through the parts to be joined or welded. The resistance offered
to the passage of the current at the point of contact produces the
welding heat; whereupon sufficient pressure is applied to effect
the union.

.Spot welding also utilizes the heat generated by the resistance
offered to the passage of an electric current and is similar to butt
welding except that heat is generated at the points of contact
between the respective electrodes in addition to the heat generated
between the surfaces to be united.

Seam welding utilizes the heat generated in a way quite similar
to spot welding; in fact, it is an extension of spot welding. A
spot weld is equivalent in form to flush riveting ; a seam weld is a
non-interrupted continuous succession of spot welds.



EVOLUTION OF WELDING PROCESSES 3

All forms of resistance welding require primarily a heavy
current at a low potential, which practically necessitates the use
of alternating current. The welding equipment, therefore, gen-
erally consists of a step-down transformer with a regulating
device ; clamps or electrodes for making the electrical connections
to the work; and suitable mechanical parts and devices for sup-
porting the electrodes, supplying pressure to the weld and sup-
porting the parts to be welded.

In general, it may be said that the resistance form of welding is
best adapted to standardized operations, especially so in the manu-
facturing field where the work can be passed through the machine.
While it might seem that the application of this form of welding is
somewhat limited there is, nevertheless, a vast field for it that has
not yet been invaded.

A comparatively recent example of the practical application of
electric resistance heating or welding is that of rivet heating,
which from all indications will soon largely supplant the fire
method of rivet heating. The rivet is heated by placing it between
copper electrodes in the form O'f blocks. A heavy current is then
passed through the rivet, and in a few seconds the proper heat is
attained. The riveting and handling of the rivets is otherwise the
same as with the fire method of heating. Some of the advantages
of the electric rivet heater are: Better control of heat resulting
in fewer rivets burned ; the rivet is more uniformly heated, thus
reducing the chances for ineffective riveting; the elimination of
smoke and dirt results in better efficiency of workmen ; and last,
but not least, the fire hazard is greatly minimized.

Thermit Welding. In the year 1894 it was found that the
ignition of finely powdered aluminum, mixed with metallic oxides,
produced an exceedingly high temperature because of the rapid
oxidation of the aluminum. These facts were turned to practical
account by Dr. H. Goldschmidt, who welded two iron bars by
molten iron produced by the process to which the name of
"thermit" is now commonly applied. This process has been won-
derfully successful and has been extensively used especially for
welding members of large cross-sections and for emergency
repairs on certain classes of work. Thermit welding is sometimes



4 ELECTRIC ARC WELDING

called a casting process, since it requires a mold around the parts
to be joined.

Gas Welding. The oxy-hydrogen blowpipe was first used
about the year 1820 chiefly for producing limelight. It was also
used in some important industrial applications, one of which was
the fusion of platinum. In the latter part of the nineteenth cen-
tury this process came into extensive use for lead burning, or
welding. About the same time it was discovered that by using
oxy-acetylene a much higher flame temperature could be secured,
which together with improved regulation of heat control, led to
the extremely rapid use and extension of the oxy-acetylene torch
to the welding and cutting of iron and steel, and other metals to a
lesser degree. While other gases have been used in place of
acetylene, the oxy-acetylene flame is by far the most widely used.
Today the oxy-acetylene welding and cutting process is used in
practically all of the metal using industries.

Electric Arc Welding. Electric arc welding is commer-
cially the most recent and newest process of any form of welding.
Benardos and Slavianoff are generally credited with the discovery
of the possibilities of the carbon arc and metallic arc, respectively,
for the welding of metals. The carbon arc process was the first
one to be used for welding metals, and was first used, on a small
scale, 30 years ago. This form of arc welding is sometimes called
the Benardos process. Not long after the carbon arc process
was demonstrated by Benardos, Slavianoff demonstrated the pos-
sibilities of the metallic arc process, but it was not until compara-
tively recent years that either was used to any appreciable com-
mercial extent.

After the first discovery of the more or less vague possibilities
of electric arc welding the progress in the development of the art
was extremely slow, due to the fact that it was only with great
difficulty that the work of development could be carried on.
There were several reasons for the existence of such a condition,
most important of which was the fact that the men who first
conceived and worked to develop and improve the welding art
were apparently versed only in one branch or phase of that
science.

It must be borne in mind that to develop this art it was neces-



EVOLUTION OF WELDING PROCESSES 5

sary to make an extensive investigation into the phenomena
existing in the arc, both carbon and metallic, when using it for
the fusion of metals. No matter how well versed a man may be
in electrical science it does not necessarily follow that he may
understand the behavior of an electric arc when used for welding
metals. On the other hand, although a man may be well trained
in metallurgy it does not necessarily follow that he can under-
stand the behavior of the metals when subjected to the tempera-
ture of the electric arc. In other words, the electrical men did not
understand, nor were they thoroughly acquainted with the pecul-
iarities manifested by the electric arc when used in conjunction
with molten metal during the welding process. And the metal-
lurgical men were not conversant with the behavior of metals
under the action of the arc stream with its attendant high tem-
perature variations.

In view of these existing conditions it was necessary that much
time be spent in research work by both electrical and metallurgical
men. Indeed, it was not until the electrical phenomena and
metallurgical phenomena were coordinated that a real beginning
was made in the development of the art of arc welding. And not
until then did the metal using industries begin to see the possi-
bilities of its use and to lend their financial assistance to its
development.

The Electric Arc. If two carbons which are connected to
a sufficiently powerful electric source are brought together and
then slowly separated the current will not cease to flow, provided
they are not too widely separated. Instead an arc will be formed
and the current will continue to flow, since the vapor formed
between the two carbons serves as a conductor for the passage of
the current across the intervening space. The temperature of the


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