ASME IX thickness qualification range.

By jon20013 (*****)

Date 06-24-2004 11:44

While the procedure itself would be qualified up to 22mm, the GTAW portion is only qualified to a maximum of 8mm. The emphasis is first based on the amount of weld metal deposited, if there are more than one process involved the thickness of each process is considered individually. Hope this helps!

By Luc HPF Date 06-24-2004 12:28

Thank you for your answer Jon, I am also interested in the minimum side of the thickness range.
In the case of the GTAW process used on its own, will I be qualified from 1.6mm (taking into account that I deposited only 4mm of GTAW for the PQR) or from 4.8mm (taking into account the initial test coupon thickness, whic was 11mm)?

By jon20013 (*****)

Date 06-24-2004 13:53

Yes, off the top of my head now... the minimum thickness would be 1/16" or 1.6mm. By the way, and just as a matter of reference, whenever I run PQR's here, I try to get the maximum thickness for each given process ~ you know of course you can also attach multiple PQR's to each WPS so if your organizartion has other similar PQR's with greater ranges reference them on your WPS (assuming you have reviewed all of the other variables) and increase the WPS range to be as broad as possible. Good luck!

By Shane Feder (****)

Date 01-28-2009 21:43

Hello guys,
I was trawling though old postings to try and find some info on this subject as I am faced with exactly the problem as noted above.
However, with all due respect Jon I would query the 1.6 mm minimum.
I may be totally wrong and if so I hope someone can point me to an interpretation that I can use to clarify the disagreement with the contractor.
If a PQR is qualified using GTAW of 4 mm and SMAW of 7 mm then as per QW 451.1 the "Range of Thickness T of Base Metal, Qualified" is 5 mm to 19 mm.
The " Maximum Thickness t of Deposited Weld Metal, Qualified" is 8 mm for GTAW.
It is my interpretation that this PQR can then be used to write a WPS with full GTAW for 5, 6, 7 & 8 mm thicknesses.
If the PQR was qualified with a base metal thickness of less than 10 mm (3/8) but still with 4 mm of GTAW then a WPS could be written for full GTAW on 1.6 to 8 mm thicknesses.
Where it gets confusing is QW 200.4 (2) states "the base metal and deposited weld metal thickness limits of QW 451 for each process, filler metal, or set of variables are applied".
That would appear to support Jons statement.
Where I am unsure is whether it should be interpreted as "the base metal ( and deposited weld metal thickness limits of QW 451 for each process, filler metal, or set of variables are applied").
Any clarification would be greatly appreciated,
Regards,
Shane

By 803056

Date 01-28-2009 22:23

I use this sketch to explain the thickness range qualified per ASME.

Each welding process is considered separately for the range of weld deposit qualified. (lower case t in the sketch)

The thickness of the base metal is based on the base metal thickness of the base metal used when qualifying. (Upper case T in the sketch)

It is important that the test witness record the thickness of the weld deposit for each process. I've rejected PQRs and WPS where there is no record of the deposited thickness when more than one process is listed.

Hope this helps.

Best regards - Al

Attachment: ASMEThkQualified27-Jan-09.pdf (49k)

Attachment: ASMEThkQualified27-Jan-09-3684.pdf (49k)

By Shane Feder (****)

Date 01-28-2009 22:45

Hello Al,
Happy New Year and Compliments of the Season.
Thank you for your response however I am not sure it covers what we are discussing.
Jon and I both have a pretty good grasp of ASME IX and yet we both disagree on the subject.
Based on the scenario I have described above which would be the minimum base metal thickness qualified - 1/16th or 3/16th ?
Regards,
Shane

By 803056

Date 01-28-2009 23:41 Edited 01-28-2009 23:54

I would go to the sketch and look at the thickness of the test plate used. What category does it fall into? 3/8 inch (10mm) or less, more than 3/8 inch (10 mm), but less than 3/4 inch (4.8 mm), or 1 1/2 (38mm) or thicker. That determines the range of thickness qualified for the base metal.

The thickness of the weld deposit qualified is a separate issue. Case in point: lets say you use a 1 1/2 inch thick plate (38mm) and you weld it with four different filler metals, each using a different process or F number.

Root layer (SMAW using F3) - deposit 1/8 inch thick - qualified to 1/4 inch max. with no minimum thickness.

Hot pass (SMAW using F4) - deposit 1/4 inch thick - qualified to 1/2 inch max. with no minimum thickness.

Fill pass (GMAW using F6) - deposit 3/8 inch thick - qualified to 3/4 inch (19mm) max. with no minimum thickness.

Back gouge second side to sound metal

Weld second side (SAW with F6) - deposit 3/4 inch thick - qualified to 8 inches with no minimum thickness

The procedure is now qualified for base metal from 3/16 inch to 8 inches in thickness based on the thickness of base metal used for the PQR. The SAW alone is qualified up to 8 inches because the deposited weld metal was at least 3/4 inch.

It would really throw a monkey wrench into the works if things were juggled so that F1 and F2 filler metals were used on the second side along with the SAW so no one process deposited a full 3/4 inch of weld metal. The procedure would no longer be qualified for base metal of 8 inches of thickness. The procedure would be limited to the thickness of the various F numbers used, which could easily be less than 8 inches.

I love ASME!

Back to your question. Converting mm to inches, I have a plate that is 7/16 inch thick welded with two welding processes. GTAW is used to deposit 1/8 inch and SMAW is used to deposit 5/16 inch. Rough conversions, forgive me if they aren't nuts on.

In my opinion, the 7/16 inch thick plate used to qualify the procedure would qualify for a range of 3/16 to 7/8 inch. The process GTAW would be qualified for deposited weld metal up to 1/4 inch and the SMAW up to 5/8 inch. The two processes together would allow you to weld the 7/8 inch maximum thickness. Either process individually could be used to weld the minimum thickness of 3/16 inch. There is no minimum thickness of the weld deposit, but there is on the base metal and it, the base metal, is the limiter for the purposes of writing the WPS. My answers are based Table QW-451.1 of the 2001 edition of Section IX. I have a newer edition somewhere, but it isn't handy.

Best regards - Al

By Shane Feder (****)

Date 01-29-2009 00:28

Thanks Al,
The response is greatly appreciated,
Regards,
Shane

By WalterJ Date 01-29-2009 04:00

Gentlemen,

This has been a lot of discussion about something that is quite simple, at least in my humble opinion.

Original question: Test coupon is 11 mm thick = T when applying QW-451, second column
GTAW deposit thickness is 4 mm = t1 when applying QW-451 Third column
SMAW deposit thickness is 7 mm = t2 when applying QW-451 Third column

Base metal thickness range qualified is 5 to 22 mm for both processes.

GTAW is limited to 2 X t1 = 8 mm maximum deposit thickness

SMAW is limited to 2 X t2 = 14 mm maximum deposit thickness

This qualifies the WPS to weld on base metals from 5 mm thick to 22 mm thick, but when using GTAW by itself, the maximum thickness of weld metal qualified is 8 mm. similarly when using SMAW, base metals from 5 mm thick to 22 mm thick may be welded, but the maximum weld metal thickness qualified is 14 mm.

While one may think that because GTAW is limited to depositing weld metal of 8 mm in thickness and that somehow limits the thickness of base metal that is qualified, that would not be true. One could weld base metal that was 8 mm thick to 22 mm thick (think corner joint. . . ) using GTAW. Same thinking process applies with SMAW.

Jon is right that one should choose test coupon thicknesses by first analyzing QW-451 and purchasing test coupon material that gives maximum ranges of qualification that makes sense for one's applications. This 11 mm coupon welded using GTAW and SMAW is perfect if you are going to weld parts using GTAW followed by SMAW on a range of thickensses between 5 and 22 mm, but then you have to make sure that the welder deposits an appropriate thickness of GTAW when thicknesses go over 18 mm or so to not violate the 14 mm SMAW limit.

Walt

By 803056

Date 01-29-2009 05:16

Hello Walter;

Good to see that you drop in time to time to keep us on the right path and provide the much needed sanity check.

Easy questions for an expert like yourself, but we mere mortals have to ponder them a while longer and think a little harder. ;)

Now that you are on board, I do need a little clarification on your reply. You gave the example of a corner joint; that being the case, is the weld you are thinking of a fillet or partial joint penetration groove weld? That is, a weld made using GTAW (as in this discussion) is limited to 8 mm in material 22 mm thick is acceptable. However, if the weld is a complete joint penetration groove weld made using only GTAW, the thickness of the base metal would be limited to 8 mm.

Am I looking at this correctly or am I missing something.

Thanks in advance for your help.

Best regards - Al