MAGM 200 Introduction to Agriculture Mechanics Getting Started Arc Welding

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MAGM 200 Introduction toAgriculture
MechanicsGetting StartedArc Welding
Mr. Conrado
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Arc Welding Equipment

• The heat needed for arc welding in obtained from
  electricity. The electric current flows from a
  transformer connected to lines from a power plant
  or an engine driven generator.
• Welders put out high amperages and therefore
  require large electrical cables.
• A welder has two cables one for the electrode
  holder the other for the ground clamp.
• Electrode holder a spring loaded device with
  insulated handles used to grip a welding
  electrode.
• Ground clamp a spring loaded clamp attached to
  an electrical cable and completes the electrical
  circuit.

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Electrodes

• A wide variety of electrodes are available to
  enable the welder to do many different jobs.
• Electrodes are classified and identified by their
  AWS number.
• Choosing the correct electrode for the
  application is the first step in producing a high
  quality weld.

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Arc Welding ProceduresStriking the arc

• Before striking the metal should be located for
  operator access, free of dirt, oil, and rust.
• Set proper machine amperage for the electrode and
  material.
• Warn other of potential eye hazard
• Position electrode tip about ¼ above material.
• Drop welding helmet
• Strike arc by quickly lowering, touching, and
  then lifting the electrode.

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Running a Bead

• After the arc has been struck the welding arc
  must be maintained. In addition electrode
  position and travel speed are critical to a high
  quality weld.
• Electrode angle the electrode should be held 10
  to 15 degrees from vertical away from the
  direction of travel.
• Arc length rule of thumb the distance between
  the workpiece and the electrode should equal the
  diameter of the filler metal
• Movement - the proper movement depends on many
  factors and comes with practice. To start try
  straight beads with no movement. Be sure to
  watch the molten pool for necessary adjustments.

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Running a Bead

• Speed when the electrode is moving at an even
  rate the weld material forms evenly spaced rings
  behind the weld puddle.
• Amperage setting the shape of the molten pool
  indicates amperage setting. Long narrow rings
  indicate amperage is too low, rings that are
  slightly wider than long indicates correct
  amperage setting, gourd shaped rings indicate
  amperage setting is too high.

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Practice, Practice, Practice