GMAW of Steel with Silicon Bronze

Date 09-24-2015 01:52 Edited 09-24-2015 02:38

G'day Tim I haven't done any Silicon Bronze GMAW however we have done a considerable amount of Aluminium Bronze overlay work with GMAW in spray mode using straight argon .I would think pulse mode would be fine also.

By Superflux (****)

Date 09-24-2015 03:36

I've used .035" GMAW Silicon Bronze (100% argon shielded) on chromed shopping carts & modular shelving, aluminum irrigation pipe, low to medium high carbon steel, all with excellent results. It can be used on sheet metal gauged stainless steel but only with fast travel speed and minimal heat input.
It seems to work best as an electric brazing technique I guess. Thicker cross sections of stainless can exhibit hot short cracking (from the copper to chrome) with excessive heat input.
Never tried with pulsing.

By fschweighardt (***)

Date 09-24-2015 12:14

Harris does an adequate job with some parameters

http://www.harrisproductsgroup.com/en/Products/Alloys/Welding/Copper-Alloy/Silicon-Bronze-GMAW-MIG.aspx

GMAW (MIG) Parameters (DC Reverse Polarity) Electrode Positive Spray transfer

Wire Diameter Amps    Volts Argon (cfh) Wire Feed ipm
.030 130-150    21-23    25 460-500
.035 145-185    23-25    30 400-440
.045 195-215    26-28    30 280-310
1/16 260-280    27-30    40 150-210

AWS A5.7 ERCuSi-A, I would try .035 and .045 see what is fastest/best. If you already own a pulsing power supply, it can make for a very nice finished appearance, but regular spray x-fer is fine too

100% argon for most applications.

There are some specialty shielding gases out there that provide some benefits for high volume operations that demand best possible appearance, mostly on galvanneal automotive materials.

By TimGary (****)

Date 09-28-2015 13:52

Thanks for the responses Guys,

I'm a bit sticker shocked over the $15 per pound price of silicon bronze wire.
Can anyone recommend a cheaper wire that would flow as easily as the SB?

Thanks,
Tim

By fschweighardt (***)

Date 09-28-2015 17:01

Is GMAW out of the question? Might be able to do a low-end spray or pulsed-spray with small wire (.035"?) and get the same sealing effect, it that is what is wanted

By TimGary (****)

Date 09-28-2015 19:28

GMAW with steel filler is not out of the question.
I'm trying to minimize distortion related with long, continuous fillet welds on sheet. (16 gage - 10 gage carbon steel)
I can do that fairly well with steel filler by running a fast downhill fillet, but then I would be concerned about throat cracking.
I was thinking that if I ran a quick downhill with silicon bronze, I'd minimize distortion through low heat input, and lessen crack potential through greater ductility.
Ideally, I'd like to does this robotically.
We currently manually caulk between stitch welds, after e-coat primer application and before top coat pait. This works well, but I'm just trying to think out of the box, looking for cost reduction. Purpose is weather proofing and corrosion prevention.

Tim

By fschweighardt (***)

Date 09-29-2015 01:53 Edited 09-29-2015 01:56

Just for clarity, you mean DAP caulk?
What sort of joint do you have. I see you have fillet welds, at you working with tees or laps, or both?

By TimGary (****)

Date 09-29-2015 12:01

Sikaflex caulk, with lap, tee, corner and flare bevel groove joints.

Tim