Why are there square holes/porosity at the end of some welds in sheet metal?

[bdevore]

I am looking at some enclosures and some of the welds have square to rectangular holes at the ends of the welds. Some appear to go all the way through and others are just into the material rather deep. The square hole is just outside of the weld. Its 1/8" plate and D1.1 does not seem to cover this. Can anyone help in anyway? I am trying to figure out how this happens and how to tell my supplier to watch for this, and is it rejectable by code?

 

[MiketheEngineer]

Robot or human weld. Seems they are not pulling away fast enough at the end of the run and "burning" through

 

[bdevore]

They are human welded. I thought that but I have never seen square holes at the end of welds before. Its not like a fish eye, it is actually outside the weld up to a 1/2" away so far.

 

[racookpe1978]

Weird. What size holes? are they all the same approx wxh, or do they differ in size?

Any rectangular, or mostly squares?

Is there any pattern to the size or nbr of square holes compared to length of weld or distance from the weld or thickness of metal?

Are your weld fillers consistent - not changing at all recently from a new manufacturer or from a new welder machine or welder operator?

 

[kingnero]

Are they related to the welding process? So they aren't there before, and they are after welding?
Clamping devices? Transportation clamps? ...Punch marks from a hammer, removing slag?

 

[MintJulep]

They are there to serve as crack initiation points.

 

[vanci]

Laminations in base material?

 

[bdevore]

They are 3/32" and slightly larger in size.

 

[vanci]

Obviously has nothing to do with welding process!! You need to UT or X-Ray the plate(s) to determine magnatude of defect. Also, refer back to the PO to reiew if any testing was done at the material supplier such as UT to check for such defects. Voids in the base material sound/ look like laminations to me. Perhaps the heat and expansion/ contraction associated with welding opened the lamination to a visible size. Is the material hot or cold rolled? Is there any forming performed prior to welding?

 

[MiketheEngineer]

Pissed off welder or loose ground ???

 

[btrueblood]

That sure looks like a purpose-made slot, perhaps intended for alignment/clamping/fixturing of the parts prior to welding? Who cut the pieces, and are they claiming the holes weren't there when they were cut?

 

[Guest102023]

Don't blame the welder this time!

 

[bdevore]

Could these be holes from Cleco fasteners? Does anyone know could these be cleco fasteners that once removed the holes are not completely filled?