OPERATION | ||
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Peak
Current
Too Low
Background
Current
Too Low
PEAK CURRENT (Figure B.16)
Peak current controls the arc length, which also affects the shape of the root. When using 100% CO2, the peak current will be higher than when welding with blended shielded gases. A longer arc length is required with CO2 to reduce spatter.
FIGURE B.16 |
|
Peak | Peak |
Current | Current |
Optimum | Too High |
BACKGROUND CURRENT (Figure B.17)
Background current adjusts the overall heat input into the weld. Changing the background current changes the shape of the back bead. 100% CO2 requires less background current than when welding with blended shielding gases.
FIGURE B.17
Background | Background |
Current | Current |
Optimum | Too High |
TAILOUT
Tailout provides additional heat into the weld without increasing the arc length or the droplet size. Higher tailout values improve wetting and may give faster travel speeds.