Multiple Arc SAW

Date 07-17-2004 04:44

I am planning to use multiple Arc SAW (3 Wires) for surfacing. Three wires will be depositing individual beads side by side with a good overlap or tie-in. All my power sources are DC and this means I must space out the electrodes. The electrodes will be offset by the amount of the bead width. I plan to use 4.0mm EL12 Wire and 550A. I have two questions:

1-What will be the bead width? This is important to decide on the electrode offset.

2-What should be the distance between electrodes ( considering all are DC arcs) so that there is no arc blow?

Thanks

R. S. C

By Len Andersen (***)

Date 07-17-2004 15:20

I am an engineer and if the question hit my desk and a good
answer meant my job. Contact the suppliers and the machines
and the consumables. The sales guy often has good info and if
not there is normally a organization to back them up. I hope
this is helpful.
Sincerely
Len Andersen
lenandersen.com

By Tim Buyle (**)

Date 07-23-2004 20:52

Bead width from SAW is depending on melting/flow rate (= current) , on arc length (= voltage) , on welding speed !!!

Imagine you are squeezing a tube of tooth paste : what will be the bead width ? This is in relation to the flow rate , the height of the tube to the table, the travel speed !!!

So ... think about this when doing some tests.

Also, think about "twin arc" welding : 2 wires in the same torch, with the same power source for surfacing : very quick, good results, easy to use !

By ajoy

Date 07-24-2004 10:24

I agree with Tim that the bead width depends on the current, voltage and the welding speed. Also, to get a relatively ripple free surface your electrode offset should be half the bead width.

Your decision to go for triple arc should depend on the following:

1. What is the hardness you expect from the hardfaced surface, knowing that the trailing arcs may temper the beads resulting in a lower hardness than specified.

2.The trailing arcs will produce higher dilution and thus lowering of the hardness value.

3. Is the job rigid enough to resist distortion at such high heat inputs.

Finally, I will suggest you to qualify the process on the job before going for production.