D1.5 PQR heat input as applied to fillet WPSs

Date 10-21-2009 16:10

Yes, you're stuck with the same range for fillet as groove. The limitations given in 5.12 and 5.13 are how far away *any* WPS, groove or fillet, can be from the qualifying PQR.

The fillet weld soundness test is an additional test on top of the groove weld PQR, showing that what you're planning to do works for fillet welds, even though you had to test all its mechanical properties on a groove weld specimen.

The upshot of this is that if you find you need to run groove welds at one set of parameters and fillets at another, you may need separate PQRs for them. Your PQR to qualify your ideal fillet weld will still be a groove weld, only you'd not weld it using the same parameters as you would a production groove weld but rather a fillet. Sometimes that means running the PQR at non-ideal parameters even for your fillet weld, with the idea that your ideal parameters will be in the qualified range.

Same thing for if you like to use a different set of parameters for your root pass as for the rest of your (production) groove weld. Might need a separate PQR to qualify the WPS for that pass. (Code allows combining WPSs within a single weld.)

Hg

By jess123 Date 10-21-2009 20:39

Thanks for the information on the fillet. I do somewhat question making a separate PQR for the difference in a root pass. If your PQR/WPS indicates the different parameters you run for a root pass and you performed that root pass (s) per those parameters in the PQR; Then performed the fill passes per the parameters for fill passes you had listed on the PQR/WPS, haven't you proved that the different parameters for the root pass and the fill passes are both qualified to be used exactly as indicated in your WPS? Isn't that the reason the WPS form has a column to indicate the pass or weld layer? I would think this is the same as when you qualify a weld with two different electrodes like a 6010 root w/ 7018 fill passes or two different processes a 6010 root with FCAW fill passes. You are not required to do different PQRs for each of these processes. By doing the processes or electrodes together as shown on the PQR/WPS, you have proven that the combination works as shown as necessary for a 5.13 Production Procedure Qualification (as long as it all passes testing). Maybe I am missing something here. Let me know if you have any more info or a spot in the code book that would indicate this. I see at the end of 5.13.3 that it indicates if a combination of WPSs is used, the variables applicable to each WPS applies. It is confusing to a point that you can not tell whether you are required to test each one separately, or the combination together. Thank you for any info you can provide.

By HgTX

Date 10-21-2009 21:02

If your root pass is SMAW, then no PQR is needed for that.

For other processes, it comes down to how different your root pass is from the rest of the weld. If you can get both root and fill passes within the range qualified by the PQR, then you only need one. If your root pass is radically different, you might need a separate PQR for that, welded entirely at the parameters you normally use for root pass (or close enough to be within the limits of 5.12 or 5.13). 5.12 gives you a lot of leeway; 5.13 not so much.

You could put both types of pass (root & fill) on one WPS (at least I've approved them that way), but you still might need multiple PQRs to qualify them both. However, this should probably be thought of more as combining multiple procedures onto a single document. 5.7.9 says you can combine WPSs within a single joint; it makes sense to put them on the same piece of paper with the picture of the different passes. But each pass is welded to a fully qualified procedure, tied back to a specific test within the allowable range of essential variables.

Your PQR is not a mockup of your production weld. Putting a root pass with your preferred parameters into your PQR doesn't mean anything. The PQR is basically a metallurgical test of how your weld metal and fusion area will behave. Your all-weld-metal test and Charpies include only the very middle of that test weld; the root pass isn't even taking part in those tests. The PQR says that you can weld this base metal with this consumable with this range of current, this range of volts, this range of travel speed. If you want to do anything outside of that range, you need another PQR (unless it's SMAW). Every pass has to be welded to a qualified procedure, which means it needs to be within the range qualified by a test reported on a PQR. There are no exceptions for fillet welds, root passes, or anything else--except SMAW.

But, again, if your root and fill pass parameters are close enough together to be qualified by a single PQR, great, you're done. In most cases, this is what happens. It's just that once in a while, especially with qualification under 5.13, the fabricator wants the root pass to be so different from the fill passes that the fill pass PQR can't be used to qualify the root pass too. If you haven't run into this, it may be because you haven't been in that situation.

Hg