9-14. Troubleshooting − Waviness Of Bead
Waviness Of Bead − weld metal that is not parallel and does not cover joint formed by base metal.
Possible Causes | Corrective Actions |
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Welding wire extends too far out of nozzle. | Be sure welding wire extends not more than 1/2 in (13 mm) beyond nozzle. |
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Unsteady hand. | Support hand on solid surface or use two hands. |
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9-15. Troubleshooting − Distortion
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| Distortion − contraction of weld metal during welding that forces |
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| base metal to move. |
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| Base metal moves | |
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| the weld bead. | |
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Possible Causes |
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Excessive heat input. |
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| Use restraint (clamp) to hold base metal in position. |
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| Make tack welds along joint before starting welding operation. |
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| Select lower voltage range and/or reduce wire feed speed. |
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| Increase travel speed. |
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| Weld in small segments and allow cooling between welds. |
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9-16. Common MIG Shielding Gases
This is a general chart for common gases and where they are used. Many different combinations (mixtures) of shielding gases have been developed over the years. The most commonly used shielding gases are listed in the following table.
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Gas | Spray Arc Steel | Short Circuiting Steel | Short Circuiting | Aluminum |
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Argon |
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| X |
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Argon + 25% CO2 |
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80% or greater Argon + | X | X1 |
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balance CO2 or Oxygen |
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100% CO2 |
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| X |
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1Limited short circuiting use
290% HE +