MIG pipe welding

[ElronMcK]

I am trying to improve my welding skill set. I am D1.1 certified in stick ("SMAW") 3G 3/4" max thick plate.

1. Assuming AWS and ASME pipe welding - say 0.2" up to 0.5" wall, out of position, short circuit GMAW-S, both shop and field
My question: Is MIG with A75/C25 common and/or industry-accepted process?

(Most of my field observation is stick or flux core for process pipe.)

2. Are the any other MIG SWPS beside those shown by AWS database (

https://pubs.aws.org/t/procedures)?

I am looking to get certified using MIG (again, to expand my skillset and opportunities), and want to use an accepted WPS, and not try to write my own pre-qualified WPS.

Thanks

 

[TugboatEng]

I can only offer an observation but for the marine side, pipe welding is mostly dual shield nowadays. It's a spray transfer process. Production is much faster than other processes. It's very sensitive to wind if working outdoors.

 

Not having a WPS won't stop you from practicing and learning; just go to the interweb and see what parameters manufacturers recommend for their products.

I advise you to take an introductory course at a local community college or training facility, it will speed up the learning process, if for no other reason that you will learn how NOT to try things.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[DVWE]

1. Assuming AWS and ASME pipe welding - say 0.2" up to 0.5" wall, out of position, short circuit GMAW-S, both shop and field
My question: Is MIG with A75/C25 common and/or industry-accepted process?

Yes, it is common with that shielding gas and yes, it is an industry accepted process. However, from a pipe welding standpoint, GMAW-S is also mostly limited to root pass welding.

Fill and cap with Spray transfer GMAW is much more common in the shop environment, especially with automated equipment. FCAW is still widely used in the shop, but produces a significant amount of fume compared to GMAW-Spray, and has been my observation that FCAW is slowly being replaced because of that.

For pipe welding in the field, FCAW is more widely compared to GMAW, but the age old SMAW still gives the wire feed processes a run for their money.



The devil is in the details; she also wears prada.

 

[DVWE]

I also highly agree with ironic metallurgist to take some introductory courses at a local community college or similar training facility.

The devil is in the details; she also wears prada.

 

[ElronMcK]

Thanks for the responses.
I should have also said that I've got decent competence with MIG, but not certification, and still a little weak on 6G.

Clarification - for out of position (say, 5G or 6G), I don't think spray is viable, unless you have a special CV machine that can pulse. Spray is awesome but only flat. Right?

a. For 5G pipe, after the root pass with GMAW-S, which process is most common to finish the groove weld ("cover passes")? Dual shield (FCAW-G)?

b. Are there any SWPS that I can review or buy that resemble what is done commonly in industry?

c. If my friend's shop already has a legit WPS for pipe, is there anything keeping me from using it to get certified to it (use as the basis of my PQR)?
Thanks

 

[TugboatEng]

Yes, spray transfer welding with dual shield uses CV supplies. It is done in all positions.

 

[DVWE]

Clarification - for out of position (say, 5G or 6G), I don't think spray is viable, unless you have a special CV machine that can pulse. Spray is awesome but only flat. Right?

That is correct.

For 5G pipe, after the root pass with GMAW-S, which process is most common to finish the groove weld ("cover passes")? Dual shield (FCAW-G)?

In the shop, probably 90% FCAW, 10% SMAW

In the field, probably 50/50

Are there any SWPS that I can review or buy that resemble what is done commonly in industry?

Looks like there are a few available through the link you provided, depending on the combo.

If my friend's shop already has a legit WPS for pipe, is there anything keeping me from using it to get certified to it (use as the basis of my PQR)?

First, understand the difference between certification and qualification. As defined from AWS 3.0, Terms and Definitions:

Certification: written verification that a welder has produced welds meeting a prescribed standard of welder performance.

Qualification (performance): the demonstration of an individual's ability to produce a weld meeting prescribed standards.

So while you can qualify to your friend's WPS, someone will still have to write you a certification document stating that you have qualified in accordance with said WPS. That WPS may or may not be acceptable for use with certain fabrication codes such as AWS, ASME, etc.

You may also want to look into AWS's Certified Welder Program:

https://www.aws.org/certification/page/certified-welder-program

The devil is in the details; she also wears prada.

 

[DVWE]

Tug, I believe the OP is asking about conventional GMAW-Spray, which is only usable in the flat position for groove welds and flat and horizontal positions for fillet welds. GMAW-Pulsed may be used in all positions, but requires a power source capable of pulse welding.

FCAW with 75% Ar / 25% CO2 provides a Spray-like transfer mode which may be used in all positions.

The devil is in the details; she also wears prada.

 

[gtaw]

Let me add my two cents to the conversation.

First, are you working as an employee or a contractor? If you are an employee, only AWS structural codes permit a welder's qualifications to be transferred from one employer to the next. And then, only if the customer (Owner) allows it. It isn't up to the welder or the contractor, the Owner (customer) has the final say.

If you are a contractor, you need to have your own WPSs. WPSs are not transferrable from one company to the next.

GMAW-S isn't prequalified. The WPS using short circuiting must be qualified by testing regardless of the governing welding standard.

Is there a SWPS covering GMAW-S? I don't know, but you can find out easy enough be going to the AWS website and hit the bookstore tab. A little fumbling around and you will find a list of all the SWPS sold by AWS.

Just my thoughts on your question -

Best regards - Al

 

Conventional Spray GMAW for in position pipe welding is a non-starter. Pulse Spray out of position is doable but requires fairly high skill.
I've seen amazing semi-auto work done on open root (5mm gap!) pipe in 5G using intelligent short-arc machines - Miller RMD or Lincoln STT. I'm sure there's examples on YT.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[kingnero]

short circuit GMAW-S

Does the -S stand for Spray, Solid or Shielded, or something else?

 

[DVWE]

Does the -S stand for Spray, Solid or Shielded, or something else?

The "S" stands for short circuiting arc

The devil is in the details; she also wears prada.

 

[weldstan]

Globular transfer has been used for all position welding for at least the 50 years that I have been associated with welding. For field welding FCAW has almost completely replaced solid wire GMAW. For Carbon and low alloy steels, I believe it has completely replaced solid wire GMAW.

 

[kingnero]

@ DVWE, thx. It didn't occur to me that it could be short arc (we use -D, for dip). What would be the suffix for spray then?

 

[DVWE]

What would be the suffix for spray then?

I'm not sure if these are absolute in codes, but industry in the USA has basically accepted the following:

GMAW-S is for short arc
GMAW-Globular (sometimes shortened to G or Gl)
GMAW-Spray (sometimes shortened to Sp)
GMAW-P is for pulsed or pulsed spray

The devil is in the details; she also wears prada.

 

[kingnero]

Thx! Another difference that's very confusing, between Europe and USA...
The -P is the same though

 

[david339933]

Not to be confused with FCAW-S which is "self shielded".

 

[ATSE]

Al mentioned WPSs are not transferable between companies. Rookie question: Where is that in D1.1-2020?

 

[DekDee]

ATSE,
The best way to progress from "Rookie" is to learn.
Best way to learn is to read.
Open AWS D1.1 and look at Section 4 - will not take you long to answer your own question.

Note: I only have the 2015 edition so unless there have been major changes it should be in the 2020 edition as well.