Weld Penetration - ANSI/AWS D14.3-94 - Qualifying welding procedures

[Jim Howe]

In ANSI/AWS D14.3-94 "Specification for Welding Earthmoving and Construction Equipment" the subject of "Welding Procedure Qualification" is discussed in Section 5. Basically it states that there are three methods of qualifying welding procedures.

Method I- Prototype Testing
Method II- Procedure Qualification Tests
Method III- Prequalified Joint Procedure

I am very interested in these methods and would like to here from fellow covers which methods they have used and/or prefer and also if there exist Studies showing the relationship between the welding parameters vs. depth penetration.

For example; if using MIG welding for steel goods, is there a correlation between voltage, wire size, wire feed speed and penetration depth? If so are there documented studies of this? Or what is considered good depth penetration for MIG? (for discussion purposes assume .045 hardwire, 28-32 volts, wire speed 460-500 in/min, and gas 50-60 psi)

I have found some references for depth (.020 -.050) when using MIG on aluminum but nothing as yet on steel.

Any comments?

 

[Miner]

I am very interested in these methods and would like to here from fellow covers which methods they have used and/or prefer and also if there exist Studies showing the relationship between the welding parameters vs. depth penetration.

For example; if using MIG welding for steel goods, is there a correlation between voltage, wire size, wire feed speed and penetration depth? If so are there documented studies of this? Or what is considered good depth penetration for MIG? (for discussion purposes assume .045 hardwire, 28-32 volts, wire speed 460-500 in/min, and gas 50-60 psi)

I have found some references for depth (.020 -.050) when using MIG on aluminum but nothing as yet on steel.

Any comments?

Have you tried:
https://www.esabna.com/EUWeb/MIG_handbook/592mig1_1.htm?

If that does not help, this is a natural for a designed experiment. A DOE will give you results specific to your application, as well as any potential interactions. You will also obtain additional information on minimizing weld defects such as pinholes, undercuts, etc.

Other factors to include are type of shield gases, ratio of gases, travel rate, and probe angle.

Penetration depth should be a drawing specification. It is typically the full depth of the metals being joined, but does vary when differing thicknesses or overlapping joints are used. See the link above under Testing and Inspection.

 

[Jim Howe]

weld penetration

Have you tried:
https://www.esabna.com/EUWeb/MIG_handbook/592mig1_1.htm?

If that does not help, this is a natural for a designed experiment. A DOE will give you results specific to your application, as well as any potential interactions. You will also obtain additional information on minimizing weld defects such as pinholes, undercuts, etc.

Other factors to include are type of shield gases, ratio of gases, travel rate, and probe angle.

Penetration depth should be a drawing specification. It is typically the full depth of the metals being joined, but does vary when differing thicknesses or overlapping joints are used. See the link above under Testing and Inspection.

Miner, I find the link to be informative, thanks! Your suggestion for DOE is echoing several other suggestions. I agree that I need to perform DOE and establish what our procedure is capable of but I was really looking for some bench mark studies. I agree that the penetration depth should be a drawing specification and I think a DOE would certainly help in understanding the process even for the Engineers.
Thanks again!
Jim

 

[Jim Howe]

weld penetration

As I continue my research on this item I find that weld current can have a dramatic effect on weld penetration. But I also find that with MIG welding the wire speed is tied to weld current; i.e., an increase or decrease in wire feed speed will increase or decrease weld current.
If you could increase weld current without increasing wire feed speed you could increase penetration but since the two are tied together I understand that weld penetration would decrease.
Can anyone positively confirm this phenomenon. I am just looking for some clue as i begin to visualize my DOE.

 

[Miner]

As I continue my research on this item I find that weld current can have a dramatic effect on weld penetration. But I also find that with MIG welding the wire speed is tied to weld current; i.e., an increase or decrease in wire feed speed will increase or decrease weld current.
If you could increase weld current without increasing wire feed speed you could increase penetration but since the two are tied together I understand that weld penetration would decrease.
Can anyone positively confirm this phenomenon. I am just looking for some clue as i begin to visualize my DOE.

If you go to the link that I provided earlier and click on the tab Power Supply, it discusses this very issue. There is a relationship between current, wire speed and voltage.

 

[Jim Howe]

weld penetration

If you go to the link that I provided earlier and click on the tab Power Supply, it discusses this very issue. There is a relationship between current, wire speed and voltage.

Thanks Miner,
Yes, I have reviewed that link and it shows a relationship in general terms. But I was looking for a more specific confirmation of the increase in (wire feed speed & weld current) vs. penetration.
As I review the weld machines and the weld operators I find that the weld operator can change the voltage and/or the wire feed speed all else is fixed. So my thoughts are to setup a DOE to study wire feed speed vs. penetration with a set voltage.
To me it seems like a good starting point. What do you think?

 

[Miner]

Thanks Miner,
Yes, I have reviewed that link and it shows a relationship in general terms. But I was looking for a more specific confirmation of the increase in (wire feed speed & weld current) vs. penetration.
As I review the weld machines and the weld operators I find that the weld operator can change the voltage and/or the wire feed speed all else is fixed. So my thoughts are to setup a DOE to study wire feed speed vs. penetration with a set voltage.
To me it seems like a good starting point. What do you think?

I agree totally. I think you would have ended up there anyway.

 

[roland_lu]

...... my thoughts are to setup a DOE to study wire feed speed vs. penetration with a set voltage.
To me it seems like a good starting point. What do you think?

Hi, Jim, what are your findings/conclusions? looking forward to your results! Thanks!

 

[Jim Howe]

weld penetration DOE

Unfortunately The DOE has been postponed. Our production requirements have all our welders consumed. I hope that we can soon get back into the discussion but sales informs me that the future holds ever increasing demand. Yes we continue to hire. will advise but please don't hold your breath!