©
COPYRIGHT 2000 THE ESAB GROUP, INC. LESSON
IX 9.2.8
Efficiency
of Solid Wires for SAW - In submerged arc welding there
is no spatter loss
and an efficiency of 99% may be assumed. The only loss during welding is
the short piece
the operator must clip off the end of the wire to remove the fused flux that forms
at the termination
of each weld. This is done to assure a good start on the succeeding weld.
9.2.9
Cost
of Electrodes, Wires, Gases and Flux - You must secure the
current cost per
pound of the electrode or welding wire, plus the cost of the shielding gas or
flux if appli- cable,
from the supplier. The shielding gas flow rate varies slightly with the
type of gas used. The
flow rates in Figure 7 are average values whether the shielding gas is an argon
mixture or pure
CO2. Use these in your calculations if the actual flow rate is not available.
In the submerged arc process (SAW)
the ratio of flux to wire consumed in the weld is approxi-
mately 1 to 1 by weight. When
the losses due to flux handling and flux recovery systems are
considered, the average ratio of flux
to wire is approximately 1.4 pounds of flux for each pound
of wire consumed. If the actual
flux-to-wire ratio is unknown, use the 1.4 for cost estimating.
9.2.10
Cost
of Power - Cost of electrical power is a very small part
of the cost of deposit- ing
weld metal and in most cases is less than 1% of the total. It will be necessary
for you to know
the power cost expressed in dollars per kilowatt- hour ($/kWh) if required for
a total cost estimate.
FIGURE 6 Shielding
Gas Efficiency
Range Average
Efficiency Pure
CO2 88 - 95%
93% 94
- 98% 96% 98%
Ar - 2% O2 97 - 98.5%
98% DEPOSITION
EFFICIENCIES - GAS METAL ARC WELDING CARBON
AND LOW ALLOY STEELS Wire
Diameter .035"
.045" - 1/16"
.045" 1/16"
5/64" - 1/8" CFH
30 35
35 40
45 GMAW
FCAW/MCAW APPROXIMATE
SHIELDING GAS FLOW RATE - CUBIC FEET PER HOUR FIGURE
7
