Tandem arc welding on a circumferential weld seam.
The following assumptions can be made regarding single and tandem wire arc welding.
- 4 mm Solid wire used in both cases.
- 1 kg wire = 10.124 metres wire.
- Welding preparation used: one third / two thirds double vee bevel, 50° included angles on a 75 thick plate.
- Diameter of mill shell = 7.5 metres.
- To fill weld seam = 269.9kg weld metal.
- Typical savings on the above welds for a mill with 2 shells and 2 flanges is as follows:
- 65% weld time on circumference seams.
- 59% weld time on longitudinal seams.
- This adds up to an overall 10% saving on the extimated works cost for a mill of the above dimensions.
Comparisons between single and tandem arc welding on a circumferential weld seam.
Below is a comparison between the two methods of submerged arc welding:
SINGLE WIRE WELDING (CONVENTIONAL METHOD). DC ELECTRODE POSITIVE
| AMPS |
VOLTS |
TRAVEL SPEED
(mm/mim) |
HEAT INPUT
(Kj/mm) |
SECONDS TO BURN OFF 1.0m WIRE |
SECONDS TO BURN OFF 1kg = 10.124m WIRE |
TIME TO FILL 1 CW (HOURS) |
| 640 |
34 |
230 |
5.7 |
50 |
506.2 |
37.9 |
TANDEM ARC WIRE WELDING (TAW)
LEAD WIRE = DC ELECTRODE POSITIVE. TRAIL WIRE = AC
| ELECTRODE POLARITY |
AMPS |
VOLTS |
TRAVEL SPEED
(mm/mm) |
HEAT INPUT
(Kj/mm) |
SECONDS TO BURN OFF 1.0m WIRE |
SECONDS TO BURN OFF 1kg = 10.124 m WIRE |
TIME TO FILL 1 CW (HOURS) |
| DCEP |
650 |
34 |
500 |
2.7 |
35 |
163.5 |
13.3 |
| AC |
640 |
38 |
500 |
2.9 |
30 |
|
|
TOTAL HEAT INPUT = 5.6 Kj/mm
DCD-DORBYL
|
