1. Shielded Metal Arc Welding (SMAW)

2. Welding
Most economical and efficient way to join metals together permanently

3. The Importance of Welding
Began as a repair or maintenance tool

4. History of Arc Welding Bronze age
gold circular boxes were made by pressure-welding lap joints together

5. Iron Age
Egyptians and eastern Mediterranean people welded pieces of iron together
forging and forge welding items found in the pyramids of Egypt

6. Middle Ages art of blacksmithing developed India Germany Scandinavia
England

7. Mid-nineteenth century
gas welding and cutting developed
arc and carbon arc welding developed
1890 C.L. Coffin of Detroit received the first patent for an arc welding process using a metal electrode

8. World War I & II brought a tremendous demand for welding
fuselages for airplanes
ships and ship repair
1920 brought first automatic welding process

9. Welding In Our Daily Lives
Bulldozers
storage tanks
Trans-Alaska pipeline
yachts and boats
automobile
railroad freight cars
Sears Tower and other buildings

10. Shielded Metal Arc Welding
SMAW
-process with an arc between a covered
electrode and the weld puddle
-consumable flux covered electrode 10

11. Welding Terms
Arc
The flow of electrical current from the tip of the electrode holder to the base metal.

12. Electrodes
Metal rods which conduct a current from an electrode holder to the base metal.

13. Base Metal
The metal to be welded or cut.

14. Arc Length
The distance from the end of the electrode to the point where the arc makes contact with the work surface.

15. Crater
A depression at the termination of a weld.

16. Face of the Weld the welding was done.
The exposed surface of a weld, made by an arc or gas welding process, on the side from which
the welding was done.

17. Flux A fusible material or gas used to dissolve and/or prevent the formation of oxides, nitrides, or other undesirable inclusions formed in welding.

18. Low Carbon Steel
Steel containing .20% or less carbon.

19. Pass
A single longitudinal progression of a welding operation along a joint or weld deposit.

20. Porosity
Gas pockets or voids in metal.

21. Spatter
The metal particles given off during welding which do not form a part of the weld.

22. Tack Weld
A weld made to hold parts in proper alignment until the final welds are made.

23. Puddle
That portion of a weld that is molten at the place the heat is supplied.

24. Undercut
A groove melted into the base metal adjacent to the weld and left unfilled by the weld process.

25. Weaving
A technique of depositing weld metal in which the electrode is oscillated.

26. Weld Metal
That portion of a weld which has been melted during welding.

27. Whipping
A term applied to an inward and upward movement of the electrode which is used in vertical welding to avoid undercut.

28. AWS
American Welding Society.

29. Deposition Rate
The amount of filler metal deposited in any welding process; rated in pounds per hour.

30. Types of Weld Machines
AC Transformer Welder current alternates direction 120 times per second

31. AC-DC-Transformer rectifier -
provides either alternating current or direct current

32. Motor Generator -
produces DC current

33. Engine Generator -
produces DC current

34. SMAW Equipment Welding Machine Electrode Holder with lead
Ground clamp with lead
Helmet #10 shade
Gloves
Chipping hammer
Safety glasses
Wire brush
Pliers
Protective clothing

35. Polarity Reverse Polarity(DCRP)
Current flows from base metal to electrode.
Base metal is negative, electrode
is positive.

36. Straight Polarity (DCSP)
Current flows from electrode to base metal.
Base metal is positive, electrode
is negative.

37. Current Flow
Negative to positive.

38. Alternating Current (AC)
current alternates its direction 120 times per second
Direct current (DC)
electrical current that flows in only one direction

39. Welding Circuit

40. Factors That Determine Polarity
Electrode
Type of flux on electrode

41. Operating Machine Adjustments
Current (amperage) Settings
Increasing amps
- produces more heat
Decreasing amps
- produces less heat

42. Polarity DCRP (direct current reverse polarity)
DCSP (direct current straight polarity)
AC (alternating current)

43. Types of Electrodes Mild Steel Low Hydrogen Non-ferrous Hard surfacing
Cast iron
Stainless steel

44. Electrode Grouping Fast-Freeze
weld puddle and slag solidifies quickly.
Least amount of slag
deep penetration
Exx10
Exx11

45. Fast-Fill weld puddle and slag cools slowly.
thickest flux coating and most amount of slag
limited use to flat groove and fillet welds in the flat and horizontal position
Exx24
Exx27

46. Fill-Freeze characteristics of fast-freeze and fast-fill.
easy to strike an arc
produces a clean weld with minimum amount of spatter
can be welded in all positions
Exx12
Exx13
Exx14

47. Low-Hydrogen characteristics of fast-freeze and fast-fill.
Produce welds with outstanding resistance to cracking under high stresses and vibration-type load conditions
do not contain much hydrogen in the form of moisture in the flux coating or in chemical form
E6015 E7016
E6016 E7018
E6018 E7028

48. Common Electrode Sizes
Size Range
1/16 to 5/16

49. Common sizes
3/32
1/8
5/32
7/32
1/4
5/16

50. Determining Electrode Size
Determined by:
the diameter of the bare end of the electrode

51. Purposes Of Flux Coating
Stabilizes the arc
Shields molten puddle from air
Floats impurities out of the puddle
Forms slag and slows cooling process
Provides deoxidizers and scavengers to prevent porosity of the weld zone
Provides alloying elements for higher weld strength
Provides iron powder to increase deposition rate

52. AWS Electrode Classification
Stands for electrode

53. Tensile strength deposited in thousand pounds per square inch
First two digits -
Tensile strength deposited in thousand pounds per square inch

54. Indicates weld position
Third digit -
Indicates weld position
1 = all positions
2 = flat and horizontal positions

55. Represents special characteristics
Fourth digit -
Represents special characteristics
1 = current
2 = penetration
3 = type of flux coating

56. Factors For Selecting Electrodes
Base metal strength properties
Base metal composition
Weld position
Welding current
Joint design and fit-up
Thickness and shape of the base metal
Service conditions and/or specifications
Production efficiency and job conditions

57. Types of Welds
Bead

58. Fillet

59. Groove

60. Plug

61. Parts of Groove Welds

62. Parts of Fillet Welds

63. Types of Weld Joints
Butt

64. Corner

65. Tee

66. Lap

67. Edge

68. Reasons For Poor Welds Improper machine adjustment
Improper electrode and size
Improper electrode movement
Improper electrode angle
Improper base metal preparation
Improper arc length

69. Parts of Welding Process

70. Methods of Striking an Arc
Tapping
Scratching

71. Adjusting The Welding Machine and Striking The Arc
Select the proper electrode considering the thickness of the material, the type of metal to be welded, and the type of welder.
Set the amperage at about 115 amps for an 1/8” electrode.
Place material on properly grounded table.
Select proper welding helmet.

72. Strike the arc as you would a match.
Raise the electrode about 1/2” off the material as the arc is established.
Slowly lower the electrode to about 1/8” from the metal as the molten puddle is formed.
If the electrode freezes, first attempt to twist it free.

73. If the electrode will not break free, use these 2 methods to break it free.
Unclamp the electrode holder, breaking the current flow.
Shut the power off at the welding machine.
Do not grab the electrode with bare hands…it may be over-heated and extremely hot!

74. Never turn off the switch while current is flowing through the electrode holder.
This would arc the switch.

75. Welding A Bead Follow the steps in striking on arc.
When the arc is established, tilt the electrode degrees in the direction of travel. (left to right for right handed welders)
Move the electrode ahead at a smooth and uniform rate.

76. Keep the electrode at the forward edge of the crater and feed it into the work as it melts off to maintain the proper arc length.
The width of the bead should be 1 1/2 times the width of the electrode. (3/8” for 1/8” electrode)

77. Welding Positions
Flat = 1

78. Horizontal = 2

79. Vertical = 3

80. Overhead = 4

81. Safety Precautions Keep equipment in good, clean, dry condition.
Make sure all electrical connections are tight, clean and dry.
Use correct size welding cable - do not over load.

82. Be sure cables, holder and connections are properly insulated.
Cut off power to welder before cleaning machine or making internal adjustments.
Never change polarity or current settings while machine is under load.

83. Observe normal operating care for electrical hazards.
Keep work area neat, clean and dry.
Remove flammable materials from work area or shield them.
Do not weld or cut on containers such as drums, barrels, or tanks until you know there is no danger of fire or explosion.

84. Dispose of hot electrode stubs in a metal container.
Never strike an arc on a compressed gas cylinder.
Protect your eyes from rays of arc welding; wear a headshield with the proper filter plates when welding or cutting.

85. Always wear safety glasses under your welding helmet for your helmet only protects you from the rays.
Helmets are not approved safety eye wear…(OSHA standards).
Chip slag away from your face.
Slag is hot and flies off the material, which could burn exposed skin.

86. Wear leather gloves and protective clothing such as long sleeves and high button collars to protect against the arc rays.
Wear additional protective clothing such as welding jackets or aprons to protect from hot sparks/slag.
Avoid exposure of any skin surface.

87. Use a non-reflecting welding curtain to protect others in the area from the arc rays.
Be sure work area has adequate ventilation-plenty of fresh air.
Precaution must be taken when welding or cutting on lead, zinc, beryllium copper, or cadmium.

88. Do not pick up hot metal, even with welding gloves.
Always use a plies to cool metal as soon as possible.
Give the word “cover” to all people standing nearby when ready to strike an arc.

89. Always open main switch or disconnect plug when checking over a welder.
Do not leave an electrode holder on a welding table or in contact with grounded metal surface.
Keep tools and metal in their proper place.
Never use equipment without permission from your instructor.

90. Take caution when removing the ground clamp after welding; it may be hot due to poor contact with the table.
Wear appropriate shoes. NO OPEN TOED SHOES ARE ALLOWED IN THE SHOP!
Never weld with a cracked lens.
Do not leave any hot metal where others may come in contact with it.

91. Always avoid looking at the welding arc with bare eyes.
Eyes can be burned with the rays from the arc.
Burns are tiny water blisters that form on the eye.

92. Safety Precautions for the Hand Grinder
Be aware of where your sparks are flying.
Always wear a face shield.
Clamp small pieces in a vise.
Make sure the switch is turned off before plugging the grinder in.

93. Safety Precautions for the Stationary Grinder
Keep fingers away from the grinding wheel.
Never grind on the side of the grinder.
Do Not use the grinder if the support is more than 1/8” away from the wheel.
Clamp small pieces in a vise-grip.
Never move guards.

94. Proper Cooling Techniques
Always cool as soon as possible.
Use a plies to handle hot materials.
Dip material slowly in water, a little at a time.
Hot material submerged in water will produce steam, which could scald your skin.

95. Defective Equipment
Always report any cracked lenses to the instructor.
Report any broken or defective equipment immediately to the instructor.
Defective equipment must be repaired or replaced as soon as possible.