MIG- Globular/spray vs. Short Circuit

Date 04-17-2003 13:28

I'm not trying to be a smart-aleck here but not having a lot of exposure to GMAW- Pulsed welding, I think I would look at the machine settings. Maybe someone on this forum can tell you some neat tricks to be able to tell, but I think you will have to be around the machines while they're in use, look at the settings, and make mental notes on what you hear and what you see.
CHGuilford

By DGXL

Date 04-17-2003 16:01

JT:
GMAW-P requires a power source that will pulse the current. The power source must have pulsing capability. It is hard to tell just by looking at the front panel, many of today's GMAW-P power supplies are synergic or one dial control which modifies all the appropriate parameters with one dial or button.

What to look for:
Argon rich gas mixture
High pitched buzzing sound during operation
Little to no spatter
Little to no welding fumes generated during welding

Short Circuiting (GMAW-S) can be performed with most GMAW welding equipment. It is a low voltage process and typically is used for thinner materials (<1/2"). GMAW-S requires procedure qualification under most codes.

What to look for:
CO2 or CO2 rich gas mixture
Crackling sound like bacon frying during operation
Low penetration profiles
Low voltage and amperage values when a meter is used to verify parameters
Small electrode diameters (.035 or less)
Weld failures due to the presence of planar discontinuities such as IF or IJP

By kam

Date 06-26-2003 12:17

DGXL
Non pulse power supplies can be used to pulse weld. All you need is a wire feeder with pulse capabilities.

kam

By ssbn727 (*****)

Date 06-27-2003 08:44

Hello Kam!
The wire feeder having a pulser will not give you true pulse capability with any non-pulsing power sources. The only way you can achieve this is by having either a built in circuit in the power source that gives you the option or a kit provided by the equipment mfr. that's purchased as an option. What I mean by this is that you need to have the pulse circuit in the power source in order to achieve true pulsing in the welding circuit. Voltage sensing wire feeders alone will not give you true GMAW pulse welding arc characteristics.
At least this is what I remember from my days as a Welding Equipment Repairperson. However, I may not know all of the many advances in the welding equipment available today. Could you please elaborate more on the type of wire feeder you're talking about? No Offense!
By the way, you're right about sounds when comparing short circuit to pulse spray. If you work with automated equipment such as robots, then you know that the power sources used with robotic cells are'nt your average "machines" . ultimately you have to have some sort of interface from the wire feeder to the power source especially on robots which are interfaced with the controllers. Unless I'm mistaken or missing something?

Regards,

SSBN 727 Run Silent. Run Deep!!!

By kam

Date 06-27-2003 13:15

You guys are correct. Just talked to my Miller rep and power supply must be pulse capable. Learn something new every day. I have several 450 maxtrons and I use 60M wire feeders. For my robotic applications I use autoinvision II power supplies. Great little units!

reguards
kam

By Ronalb

Date 04-17-2003 16:56

We do alot of short arc welding where I work. We run C25 (75% Argon 25% CO2). When the machine is set right it will sound like a bunch of bees buzzing. This is the sound of the short circuiting process. Typically it is not recommended for any thickness above 3/8" since it is not a HOT welding process.
Pulsed arc tends to run a little hotter and sounds more like the bacon frying or spray arc than short arc does.

Most pulsed arc machines will have the word pulse on them, except for Lincoln who refer to most of theirs as wave or power wave.
Ronald Bergeron

By kam

Date 06-26-2003 12:11

Ron

I think you may have your arc sounds reversed. Pulsed arc, when set properly sounds like a bee buzzing. One time I switched an automated welding station over to pulse without telling the operators. When they came in and cycled the machine and heard this sound they shut the machine down and called maintenance. Short arc is the one that sounds like bacon frying.

kam

By wjason25 Date 06-26-2003 01:09

Jt:

Jason with KA Here. I Had a Few questions for you and am hoping you selected the e-mail option with your post. Please contact me at wjason25@aol.com