Welder is already qualified to D1.1 using Group I & II mat'l

Date 02-23-2011 12:37

Hi Guys,
I'm trying to help another small weldshop get their welder qualifications up to snuff and I have a question for the forum regarding D1.6:2007.
a little background info:
We recently went through and qualified all of their welders to D1.1 on Group I & II materials in 3G on 1" plate w/ FCAW. All of the D1.1 WPSs are in place and all is well with the Carbon Steel stuff,

....however they have a couple of non-structural (FCAW) fillet welds that use a 4" SS 304 pipe to A36/A709 plate and is welded with the pipe in the vertical plane and the plate in the horizontal plane so the welding is like welding on a flat table.(mainly seal welds to hold a non pressurized mineral oil from leaking out)

Question for the forum:
Am I correct in assuming that we have the Welder's Qualifications for this (FCAW) fillet weld taken care of already per D1.6:2007 clause 4.7.5 because they passed the 3G D1.1 qualifications on Group I and II materials w/ FCAW?

Already qualified the WPS for this joint (SS Pipe to CS Plate) and will qualify one more fillet weld WPS using SS Plate to CS Plate as time permits, just want to make sure the welder's quals are bullet proof. They don't mind retesting their welders, but I thought they may already have this covered and wanted to bounce this off the forum first.

By jarcher (**)

Date 02-23-2011 14:43

If I remember correctly (I don't have a copy of D1.1 at hand) base materials are not an essential variable for WPQR's. I'm sure someone will help out by citing chapter and verse.

By Kix

Date 03-03-2011 00:53 Edited 03-03-2011 01:04

John,

Check the welder performance essential variables table in D1.1. I don't have the book in front of me , but I know GAS is not an essential variable for welder qual if you had to change gas for a different FCAW wire. You may want to check on some of the other essential variables for wire composition and material makeup. I know welder performance essential variable are pretty slim so in saying that, you're probably good to go. Now you have to think about what Al had to say which is a very valid point. You could give them all an unofficial fillet weld test with the wire and pipe/plate coupons to see how they do before the wreck a production part. FCAW with any wire is tuff to get fusion all the way to the root in the 2F position if you're not on your game.

Kix

By jarcher (**)

Date 03-04-2011 05:12 Edited 03-04-2011 05:15

Actually 304 SS to low carbon weld is outside the scope of D1.1 strictly speaking. You couldn't do a WPS under D1.1 between low carbon and stainless because stainless is not covered in D1.1. I'm not familiar enough with D1.6 to say whether low carbon to stainless would fall under that code. At any rate, for the reasons I stated, I think it would the welder qualification might be done under 1.1, although you would have to qualify the WPS under 1.6. I really wish I had a 1.6 available so I could research whether it would cover carbon to stainless welds. If it does, the prudent move is to qualify your welders to a D1.6 WPS. From the description of the welds, probably the EOR would sign off on Al's nick-break suggestion.

Revision: Added info

By Kix

Date 03-04-2011 19:53

I believe he has a WPS qualified under D1.6 if you look back in his original post. I also believe there is a clause in D1.6 about welder performance qualification under D1.1 being acceptable. Like you, I do not have a D1.6 code book handy and cannot quote chapter and verse, but I'm sure John is on top of that aspect of it. I know D1.1 quals are good when building to D1.3 as long as you stay within the welder performance essential variables of D1.1.

By 803056

Date 02-23-2011 15:56

This is a situation where prudence trumps the code requirements regardless if what is suggested is permitted by the code.

We know from past experience fillet welds can be problematic with regards to obtaining fusion to the root, especially if they are small and the heat input is low. The stainless weld pool is sluggish and tends to bridge the root area. It is in the client's best interest to verify the welders can deposit welds that are defect free. It is prudent to test the welders with a mockup of the actual production configuration and do a simple break test to verify fusion is obtained in the root and they can make an acceptable start and stop with an acceptable weld profile.

Best regards - Al