Slag Inclusions

Date 01-28-2005 20:35

5.26.1.3 says unacceptable slag inclusions shall be removed. As you pointed out, 5.30 says the slag is to be removed and the adjacent base metal cleaned (such as with a wire brush). I see nothing that says any slag is acceptable on the surface (only inside while doing RT or UT). I interpret that to say no slag is acceptable on the surface. I think the slag needs to be removed from a slag pocket to determine what the weld really looks like. It then should be compared with code acceptance criteria. If a particular welder is consistently having this problem, his supervisor should be notified so some sort of correction can be made.

Someone has to remove the slag. It is my opinion that it is really the welder's responsibility to remove slag. I "fight" with welders and production about the amount of slag and spatter left on welds. Since I believe welder should be the first to VT their own welds, when I find significant amounts of slag, I ask them how they performed that VT. Blasting (depending upon cleanliness level such as brush blasting) does not always remove it. Galvanizing operations do not remove slag but sure highlight it when pieces get back. Loose spatter is a problem at the coating operation. When it gets bad, I don't inspect the pieces until the supervisor sends the welders back to clean them. But reality says I carry a flashlight and a chipping hammer to do my VT. I have never in my weld inspection career (at fabricators or during field erection) been blessed with welders that completely clean their welds so that I did not have to occasionally clean some slag or spatter while inspecting. Seems like a fact of life.

By mksqc

Date 01-28-2005 23:04

It seems to me you answerd your own question,5.30 indicates all slag is to be removed.As for a slag inclusion on the surface of a weld even if it looks insagnifigant on the surface you dont know what is under the surface.

By thirdeye (***)

Date 01-29-2005 19:06

Table 6.1 is the visual inspection acceptance criteria. Discontinuities, such as cracks, undercut & porosity are specifically addressed, but surface slag inclusions are not specifically addressed.

For a point of discussion, slag is entrapped in surface voids, of various shapes, (rounded & elongated) within weld beads, between adjacent weld beads or in voids between the weld and the base material. Thorough fusion does not exist in these "void" areas. No areas of non-fusion are allowed.

By jfwi

Date 01-31-2005 18:49

I was the CWI that caused the question.

The weld was a 2” long 3/16” fillet. There was a slag inclusion 3/8” in length The slag inclusion did not reach through the entire leg of the fillet to the root of the weld, but did reduce the leg by nearly an 1/8”.

By jwright650 (*****)

Date 01-31-2005 19:47

jfwi,
If I saw that weld that you just described in our shop, the welder that made it would have a grinder in his hand taking care of it and rewelding it before it was signed off and left our shop. I wouldn't have even bothered looking up the verbage to quote it to the welder. It plain looks bad on our shop, I only have a few welders that would argue about fixing something like that, but they would fix it, like it or not. "Most" of our welders look at thier own welds, when they chip off the slag, and would have fixed it on thier own without being told to. It's a "pride thing" with the majority of welders. They like thier stuff to be right when they call you over to inspect their work.

Don't sweat it, you made a good call to have the weld repaired. How long would it really take to fix it correctly, a few minutes at the most. Then there is no worry of field inspectors picking over the rest of your work because they found something like that and figured there had to be more, if you had let that one go.
John Wright

By CHGuilford (****)

Date 01-31-2005 22:44

John,
To build on what you implied but didn't directly say, most times it takes longer to argue about the 'discontinuity' than it does to fix the problem and move on.
And you are absolutely right, when we see a problem weld, we can't help but think "how many more are like that?" If it looks good, then usually no one digs very much deeper, if at all.

Chet

By waynekoe (**)

Date 02-02-2005 05:16

When in doubt, bust it out!

By NEQA

Date 02-23-2005 16:39

I am kinda late with this, but I have always told my vendors to read D1.1, 5.30.2 - that seems pretty clear to me. But since some shops still didn't quite understand it we now write in our Contract Spec. (which always takes precedence) that upon completion of welding all weld splatter, flux, slag and burrs shall be removed.

By GANESAN NALLATH (*)

Date 07-24-2006 19:25

Hi Friends. I'm new to QC world. Pls help me understand clearly about slag inclusion not welding slag acceptance criteria. AWS D1.1 Table 6 take clear stand on Visual Acceptance/Rejection level for porosity although it is not not accepted by most client for coating reasons. AWS D1.I do address/provide clear info on acceptance/rejection level for slag inclusion. Can someone shed some light on this.Thks.

By jwright650 (*****)

Date 07-24-2006 19:39

I take slag inclusions as a form of lack of fusion(AWS D1.1:2006, Table 6.1(2)) and should be corrected per 5.26.1.3.
If there is slag, thorough fusion cannot exist.

By hogan

Date 07-25-2006 18:09

i agree, it should be rejected for non fusion. indication open to the surface are the most detrimental

By jfwi

Date 07-28-2006 19:31

5.30.2 "Slag shall be removed from all completed welds and the weld and adjacent base metal shall be cleaned by brushing or other suitable means."

That would mean no slag will be left on or in a completed weld. Then there is the lack of fusion problem.

Jerry

By vonash

Date 08-06-2006 01:43

Clearly non-fusion.