How can I simplify WQR's for unassigned materials

By jon20013 (*****)

Date 10-16-2007 12:04

None that I'm familiar with. Will wait for Marty or js55 to chime in...

By js55

Date 10-16-2007 14:14

You can, but. Operating outside of code bodies is done all the time for different applications and different materials and different services etc. But you can't call it ASME any more.
And what would this look like in court if there were a failure? Do you, or your company, wanna take the responsibility for this? Is your engineering good enough to build a documentation base to support your action?
So it depends on your customer, your supporting documentation, to justify your system freeing itself, and whether or not you really want to go this route.
Most people try and find code systems that they can apply to an application that really has none. This seems to me the reverse. And my personal advice would be to reconsider.

By MBSims

Date 10-17-2007 03:38

For welder qualifications, read QW-423.1 closely:

"...When a base metal
shown in the left column is used for welder qualification,
the welder is qualified to weld all combinations of base
metals shown in the right column, including unassigned
metals of similar chemical composition to these metals."

By jon20013 (*****)

Date 10-17-2007 09:21

Marty, I was familar with QW-432.1 when making my own posting but the way it was posted made it sound like the person has all unassigned metals that they're dealing with so thought it would be a cluster f*** even beginning such a simplification... not to mention hard to explain to audit / survey folks.

By sim Date 10-17-2007 11:53

OK, thanks for the responses. If I qualify welders on the materials in the left column of QW-423.1 I am covered for unassigned materials of "similar" chemical composition to all those on the right. That is clear. But, what does ASME deem as being similar in chemical composition? Where do we draw the line when mechanical properties are not considered for purposes of the WQR?

By js55

Date 10-17-2007 13:34

sim,
QW-423.2 explains. It would rely upon matching the specification requirements (chemical and mechanical) of an assigned metal. For example ASTM A-XXX.

By js55

Date 10-17-2007 13:49

But in my opinion, the idea of QW-423.2 is not to find a way to 'Grandfather' in, so to speak, unassigned metals, but to 'Grandfather' in unassigned metals that are matches of assigned metals, but are manufactured under as yet, unaccepted or never to be assigned, international standards or specifications. In other words, you may have an exact match of say, TP-310, but it is manufactured under a European spec.
But I get the sense that what we are talking about here is as yet unassigned proprietary alloys. In which case QW423 is probably not a solution.
Another course of action is to correspond with ASME Section IX (and perhaps the Section II guys-there is a materials sub group that communicates data to Section IX on a regular basis) and request assignment of the alloys you are talking about. They meet 4 times a year at Code Week. Requests for the assignement of alloys is an ongoing process. This clearly is a long term solution, but it is at least something to consider.

By js55

Date 10-17-2007 13:57

And just brainstorming here too, you need to be careful when assigning alloys a number in compliance with QW423.
Small elementary changes can cause huge changes in machanical properties. For example V, Nb, or B, wherein volume percents such as 0.00X could make or break a difference. And you may have one of these powerful elements not prohibited, or even addressed, in some specs and purposely added in an unassigned spec that is the very difference between the two.
It is important to maintain the spirit of QW423 as well as complying with the letter.

By sim Date 10-18-2007 11:05

You are correct; I am referring to propriety (heat-resisting steel and nickel type) alloys, unfortunately with most bearing little in resemblance to those in list in ASME IX. It seems that requesting for assignment may well be worth a try for the long-term solution. Many thanks.

By js55

Date 10-18-2007 13:34

If you do begin the process of requesting assignment, bring data. Lots of data. Get in touch with Bill Newell over at Euroweld. I believe Bill still sits on the materials subgroup.

By jon20013 (*****)

Date 10-18-2007 15:35

ASME is receptive to considering new materials and there's an Appendix in the B&PV that interested parties can complete for consideration. One has to pretty much have their duckies in a straight line when making such requests and it seems unlikely (from a commercial aspect) that company's with proprietary materials would go through these motions.

Two more get-up's and me and my wife are off to New Zealand until mid-November!~!!! (It's just entering Springtime in NZ)....

By js55

Date 10-18-2007 16:09

Stop in at the Shire and say hello to Sam for me.

By jon20013 (*****)

Date 10-18-2007 19:45

I'll be doing it, for sure!!! Actually, where I'm going to be staying, the Shire is only about 1/2 hour drive...

By js55

Date 10-18-2007 20:56

That'd put you somewhere between the Brandywine and Bree.
OK. I'm done.

By MBSims

Date 10-19-2007 03:56

This is an important bit of information. If you are welding proprietary alloys that have no P-Number, then they are also not listed in ASME Section II Part D and have no allowable stress values assigned to them. Therefore, you're application is not in compliance with the ASME Boiler Code (unless the proprietary alloy is addressed in a Code Case) and you must be using ASME Section IX for convenience. If this is the case, you have some latitude to group the unassigned base metals with similar alloys that do have P-Numbers for the purposes of performance qualification.

So, the question is: Is this a pressure-retaining application that must meet ASME Code or is it something else?

By MBSims

Date 10-19-2007 04:10

If the material is not being used in an ASME Boiler Code or B31.x application, it won't be assigned a P-No. or S-No. You may need to use another standard, such as AWS B2.1, or use ASME IX as a guide only, or find a qualification standard that is intended for your application.

By MBSims

Date 10-19-2007 21:46

Mechanical properties are not a performance qualification requirement. That would be correct for procedure qualification though. For welders, you are demonstrating their ability to produce sound welds. Minor changes in elements that affect mechanical properties don't typically change the welding characteristics. That's why there are P-Numbers and F-Numbers to begin with. Also, the words say "similar" chemical composition, but not "matching". I don't see where it is necessary to completely meet the chemistry range of a material that has an assigned P-No.

By sim Date 10-22-2007 08:57

No, neither do I. Of our proprietary alloys, we may be talking up to 10% differences on major elements Fe, Ni, & Cr from those assigned materials, but in determining what we can consider "similar" in terms chemical composition, is not clear, and it seems too risky to make ones own assumption beyond the listed chemistry range.

By js55

Date 10-22-2007 15:34

Marty is right, a grouping of alloys is a ligitimate and justifiable position for performance quals, my legal alarm notwithstanding. Even for procedures.
But, with proprietary's you don't have a P No. You probably don't have an F No. Unless you are using a codified filler (not unusual) in which case you still might not have an A No. You're gonna have to use your own logic and data for justification.
I believe the justification for perfomance quals would have to be more 'welding characteristic' oriented than say element percentages. Though percentages could certainly be considered, and perhaps buttress the argument. The F No. system however should be used as at least a supporting guideline. But in my opinion, even though this is critical to getting some third party approval, it is still just a guideline.

If you take a look at alloys in virtually any P No grouping you will find elemental variations greater than 10%. Yet the P No's are still grouped as such for perfomance quals, because their welding characterisitcs are similar. That is the criteria you need to work with.
Take Grade 91 and Grade 11 specifically. Cr content in these two alloys varies by what? 70%? 80%? And yet, they are the same P No. Becasue their welding characteristics are similar. In the end you will have some tough decisions given enough proprietaries and will have to rely on communication and feedback from your approving governing body. Not to mention your cutomers.

By MBSims

Date 10-22-2007 22:40

I think I know what you mean, but the P-Nos. are not the same for Grade 91 (P-No. 5B) and Grade 11 (P-No. 4). However, they are grouped together for the purposes of welder performance qualification ranges for base metal P-Nos. and filler metal F-Nos.

By js55

Date 10-25-2007 17:43

Thanks Marty. Sorry for the belated agreement. Grade 11 is P4.
I started my argument thinking in terms of Grade 22. When I shifted to Grade 11 to emphasize it even more I brain farted on the P No.
And thinking of this, have you ever tried explaining to the uninitiated, if you are dealing for example with SA-335, and others, how P11, P22, and P91 are also P4 or P5.
I think they did that on purpose to mess with our heads.
Who says code week ain't good for a laugh?

By 803056

Date 10-27-2007 12:22

I just finished reading this thread and find it interesting to say the least.

No mention of the nature of the base metals being welded has been offered or I may be simply missing it.

The application doesn't have to be for a pressure retaining system to require qualification per ASME Section IX. It may be a case where the purchaser is using Section IX as a means of obtaining a comfort level that the welders are qualified in a systematic manner. I'm not sure that I would have elected ASME Section IX if that is the sole purpose, but it is what it is.

I would simply categorize the base metals generically as carbon steel, high strength low alloy, nickel, copper, nickel copper, copper nickel, heat treatable aluminum, non-heat treatable aluminum, etc. I would not try to group them into P-numbers for the purpose of welder qualification.

Again, without a PQR, none was mentioned in the post, there is no way this application can be for pressure retaining systems. ASME Section IX would only be used as the mechanism or approach used to qualify the welders with regards to the number of bends, radiographic requirements, positions, etc.

Again, limited information offered, limited replies given.

It's good to see that we have our best minds working on this. I mean it as a complement gentlemen. I view you as our ASME experts as I'm sure everyone else does as well. Hope you are going to the welding show. If you are interested in getting together, drop me an e-mail.

Best regards - Al

By sim Date 11-01-2007 12:45

803056, with all due respect, these are heat-resisting steels and nickel based alloys, as mentioned. I appreciate that using ASME IX does not necessarily have to pertain to a pressurised system, but as you quite rightly point out, in my world of pressurised systems, I failed to specify that we are in fact talking about one (and a PQR of course). But despite this, I have to say; I think the replies are far from limited; this has been a good brainstorming session to say the least!

Getting back to the original question (with pressurised system addressed), I fear it would be very risky to assume that generic categorisation is OK. We have a grey area here for those (albeit few) producers of proprietary materials and fabricators alike. In our company, qualifying the welder performance on every proprietary combination is how it has always been done and things are it seems unnecessarily complicated. As fresh blood, we are just looking for ways to simplify things a little.

Many thanks to you guys. I will have more questions to air shortly.

Best Regards

Sim

By 803056

Date 11-01-2007 15:25

I completely agree. If you are designing or fabricating a pressurized system that has to be compliant with the ASME B&PV codes, you are bound by their requirements. Any WPS utilizing an unlisted base metal would have to be qualified and the welders qualified with the base metal listed by the WPS/PQR.

As I stated in my reply, some companies reference ASME Section IX as a rational basis of qualifying their welders. They are not fabricating vessels or systems that have to meet any specific codes, so they are not constrained by code requirements and have considerable latitude in design and fabrication. However, using ASME Section IX as a basis of welder qualification provides their customers with a certain level of comfort to know the welders are qualified by standardized tests and methods of evaluation.

Life does get complicated when the contractor elects to use an unlisted base metal or filler metal in a code compliant environment. The combinations of several unlisted base metals and unlisted filler metals could keep a welding engineer busy just managing the paperwork.

Best regards - Al