Shielded Metal Arc Welding (stick welding)

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Shielded Metal Arc Welding(stick welding)
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Uses

• Farms
• Service Stations
• Large Construction Sites
• Pipelines
• (Most used type of Welding!!!!)

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SMAW Safety

• Cover all skin to prevent Radiation burns
• Cover hair to prevent sparks setting hair on fire
• Wear ear plugs to protect from noise and burning
  ear drums with sparks
• Use a 14 shade welding helmet to protect eyes
• Wear safety glasses at all times
• Make sure pants pockets are empty

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Duty Cycle

• Length of time a welder can be used continually
  at its rated output in any 10 minute period
• Thunderbolt AC/DC machines are 20 duty cycle
• At 150 amps DC welder can be used for 2 minutes
  in a 10 minute period.
• At 100 amps DC can be used about 5 minutes in a
  10 minute period.

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Electrodes

• SMAW uses a consumable electrode that contains a
  flux coating
• The flux produces a protective gas around the
  weld
• CO (Carbon Monoxide)
• H2 (Hydrogen)
• Removes impurities from the molten metal
• Forms slag to protect weld as it cools

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Electrode Care

• Electrodes must be kept dry
• Dampness will introduce hydrogen into the weld
  causing cracking or brittleness
• Damp electrodes may cause the flux to blow away
• Questionable electrodes should be baked at 250 F
  for several hours.
• Our electrodes are stored in a dry oven

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Electrode Identification
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Electrode Characteristics
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Electrode Characteristics continued
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Our Electrodes

• E6013
• E Electrode
• 60 60,000 psi Tensile Strength
• Tensile Strength Maximum pull stress in pounds
  per square inch that a specimen will withstand.
• 1 All positions
• High titania potassium

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Our Electrodes

• E6011
• E Electrode
• 60 60,000 psi Tensile Strength
• 1 All positions
• 1 High-Cellulose, potassium flux composition
• These electrodes are good for low carbon Steel

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Electricity

• DC- Direct Current
• Electrons Flow From Negative to Positive

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Type of DC we will use

• DCEP (Direct Current Electrode Positive)
• Electricity flows from through ground clamp to
  the work across the arc and back to the welder
• Arc Temperatures reach 6500 to 7000F

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DCEP(Direct Current Electrode Positive)
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Setting up the Welder
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AC vs. DC

• DC
• Heat Concentrated at Work piece
• Forceful, Digging Arc
• Medium to Deep Penetration

• AC
• Heat Concentrated at Electrode
• Lower Penetration
• Increased Deposition Rates
• (used for welding thin metal)

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Approximate Amperage Settings
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Setting up the Welder

• Plug ground cable into the (-) terminal
• Plug the electrode holder cable into the ()
  terminal
• Turn on the welder
• Select DCEP (Direct current electrode positive e
• Select correct amps

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Striking the arc

• Scratch method
• Start with electrode 3/8 from where you wish the
  weld to begin
• Drag the electrode along the metal until the arc
  begins
• Straight down Method
• Hold electrode straight up and down and tap metal
  until arc begins

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Starting The Arc
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Running a Bead

• Important to keep
• Proper arc gap
• About 3/16
• Should sound like sizzling bacon
• Forward motion
• Need to maintain proper bead width (about 2-3
  times the width of the electrode)
• Electrode angle
• Tipped forward 20 in the direction of travel

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Restarting Interrupted Bead
1. Strike Arc Here 2. Move Electrode to Crown of
Crater 3. Resume Travel Forward
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Finishing a Bead

• Run bead onto scrap piece of metal connected to
  work piece
• Reverse electrode direction at end of weld to
  fill the crater

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Cleaning the Bead

• A protective layer of slag will be formed on the
  weld
• Allow weld to cool than chip slag with a chip
  hammer
• Wire brush to remove all slag
• Slag must be removed before another weld can be
  added.

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Sample Beads For Quality Welding
Travel speed too slow

• Good

Amps too low
Amps too high
Arc Length too short
Arc length too long
Travel speed too fast