American Welding Society Forum
Hello experts pls answer this question,
A PQR was qualified as per ASME SEC IX with two process, GTAW and SMAW with weld metal deposit thickness (t) of 8 mm each in a 16mm base metal thickness (T) of plate. What will be the BASE METAL THICKNESS range T (not deposited weld metal thickness) if a WPS is prepared with only GTAW process supporting the above PQR?.
Here are few ranges;
1). Base metal thickness range 5 mm to 32 mm and deposited weld metal thickness upto 16mm
2). Base metal thickness range 5 mm to 16 mm with a max deposited weld metal thickness of 16 mm
3). Base metal thickness range 1.5 mm to 16 mm with a max deposited weld metal thickness of mm of 16 mm
#No impact test requirements.
In my opinion option 1 is correct
Am I right
OK, now I have my Section IX handy.
Two welding processes were used to weld the full 16mm (0.630-inch or 5/8-inch)thick test plate.
Each process was used to deposit 8mm (0.315-inch or 5/16-inch) of weld, i.e., 8mm with GTAW (0.315-inch or 5/16-inch)and an additional 8mm (0.315-inch or 5/16-inch)using SMAW.
GTAW can be used by itself to deposit a maximum thickness twice the thickness deposited in the test assembly: a maximum thickness of 16mm (0.630-inch or 5/8-inch).
SMAW can be used by itself to deposit a maximum thickness twice the thickness deposited in the test assembly: a maximum thickness of 16mm (0.630-inch or 5/8-inch).
The two processes can be used in combination to weld a maximum base metal thickness of 32mm (1.25-inch). Either process or both processes in combination can be used to weld the minimum thickness of 5mm (3/16-inch).
Per Table QW-451.1, make sure you review the footnotes to see if they apply.
If i write a single WPS for GTAW alone then what will be the qualified base metal limits? Is it 5 to 32mm?
AI Could you point out an interpretation or clause regarding the same ?
Do we have to consider each process as an individual one and have to take their deposited weld metal thickness as the base metal thickness?
Can we use such a WPS to make weld a joint of dissimilar thickness on BM of 16 mm and 32mm thick by GTAW alone?
The maximum thickness is 2 X t where t is the thickness of the weld deposited with each process when more than one welding process is used to weld the full thickness of the groove.
Take a look at Table QW-451.1 where t is the thickness of the test assembly, t is the thickness of the weld deposit. Read the footnotes and the referenced articles.
No interpretation is needed, just read what is written.
If you are going to write a WPS for GTAW only with the base thickness mentioned in your post. It will be 2t. typically (without measuring each pass) deposited weld metal for GTAW root=0.0625, second pass would be the same. Root and second pass with GTAW=0.125. 2t=0.250. so now due to your PQ base metal being 16 mm your held to 5 mm min.(See QW-451.1) and .250 (6.3 mm) max. Its always base metal thickness and weld metal thickness that gives you your parameters. QW-451.1 is pretty clear. So to answer your "Is it 5 mm to 32 mm" question. No for GTAW alone. Its 5 mm to .250 (6.3 mm)
IMHO a 16 mm plate can be welded to a 32 mm plate with GTAW only with this WPS.
As noted by Al,
BM qualified is 5 to 32 mm
DWM is 16 mm max
His post shows two different welding processes. GTAW SMAW. Per QW-451-1 maximum thickness of deposited weld metal qualified is 2t, not 2T. 2t=two passes GTAW=.125 x 2t=.250, not 5/8" inch or 16 mm, since he used two welding processes and he wants to use just the GTAW side of this PQ is he not held to max weld metal thickness for that process? what am I not seeing here that you are?
The requirements of QW 451.1 state " Thickness of test coupon welded" which is 16 mm.
Therefore the qualification range is 5 mm to 32 mm for base metal.
The GTAW portion of Deposited Weld Metal is 8 mm so 2 x t = 16 mm.
2 x 32 mm plates could be welded together in a Single Vee configuration but only 50% (16 mm) could be welded with GTAW.
Or, (as I am presuming the OP is meaning) a 16 mm plate could be welded to a 32 mm plate with a Single Bevel configuration.
Both maximum BM and maximum DWM have been complied with.
If I get a chance I will hunt down some interpretations to clarify,
Yep. that is my disconnect. aravindkm002 does say they deposited 8 mm for the GTAW portion. I missed that and assumed he did like I do when we qualify a GTAW/SMAW PQ and only put a total of .125 (3 mm) of weld metal in the joint and remainder is SMAW. Thanks for the help.
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