Spray Transfer Mode vs. Globular Transfe

By Lawrence (*****)

Date 03-29-2006 20:26

Jaybird

For the most part all I can say about globular transfer is that you should avoid it.

The Globular transfer mode consists of a semi-open arc with weld globs transferring across it. The globs (rather than dropletts) are larger than the wire diameter (often much larger) and from time to time will short circuit as the large *globs* of molten wire touch the work whilst still part of the electrode. The large globs are a cause of poor sidewall fusion and the short circuiting is a cause for large quantities of spatter. Globular transfer is most often observed when poor fitups and large gaps must be filled... Production practices along these lines are akin to "slugging"

Globular transfer may also occur if voltage settings for short circuiting transfer are too high.... Or spray transfer voltages are too low.

Spray transfer is an open arc process where the electrode is consumed into the arc plasma as tiny droplets (smaller than the electrode dia.)

Both modes are limited to the flat and horizontal fillet positions with some sloppy work possible with Globular in Vertical with downward progression.

By 357max

Date 03-30-2006 00:38

Well said Lawrence. Also a note to spray with a steel wire you need at least 80% Argon in the gas mix. 75% Argon is easy to get into a globular with too much voltage.

By jaybird Date 03-30-2006 01:10

Guys, we use Ampcotrode 46 to weld Ni-Al-Br, 1.5 in. deep single V groove, with a 3/16 in root opening. We mig weld with 100% Helium 1/16 in. electrode. Our voltage parameters are 26-29, amperage 250-290. We always used globular transfer at the Shipyard. What parameters do you suggest. We weld any steel with SMAW.

By ssbn727 (*****)

Date 03-30-2006 11:06

Hi Jaybird!
May I ask what your IPM's (Wire feed speed) you're running with those parameters???

The reason I ask is because your volt/amps settings are in the spray transfer range and, if your using 100% Helium for your shielding gas then you must be getting some real good penetration...
It's been awhile since I heard of someone welding Ni-Al-Br (Nickel/Aluminum/Bronze)...
May I ask what you're building??? What shipyard???

Respectfully,
SSBN727
Run Silent... Run Deep!!!

By jaybird Date 03-30-2006 13:29

We have a Thermal Arc (Thermadyne)Wire Feeder setting between 3-4 (10-12 o'clock). Miller Deltaweld 452 CV.
If we use argon, would that change our parameters? After viewing the link from the last post I understand a little more. I've been welding for the Navy for 26 years. I'm a graduate apprentice (welding) from the Philadelphia Naval Shipyard. The Yard closed in 1996. I now work at a facility that makes the things that move a SSBN. I transferred here when the Yard closed. I'm now the welding supervisor. Most of our work is done with GMAW. What parameters would you suggest for welding with helium, we use 1/16 inch wire. Would .045 be better? We recently completed a weld project where we had numerous linear indications after UT inspection. The repairs were made, but man did it set us back a bit. We have another project coming up that will require the same weld joint configuration. We're looking for better results the next time. Thanks for your responses. I look forward to visiting the forum.
Fair winds, and following seas.

By panaya

Date 03-30-2006 06:35

See www.weldreality.com

By jaybird Date 03-30-2006 13:40

Thanks for the link, very informative.