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Up Topic American Welding Society Services / Certifications / Fillet weld PQR question
- - By ctacker (****) Date 01-08-2012 03:23
I've been asked to qualify a procedure Using A514 material to A53 pipe (plate on the end of a pipe, similar to a base plate on Column) Using an ER110 Electrode (FCAW).
  
My understanding is I need to weld the plate to pipe, do 3 macro's and ALSO Since the ER110 and A514  is not listed in clause 3 , I need to weld a plate for 2 side bends and weld metal tension test. Is that correct?  (I have never been involved in a Fillet PQR )

I know I should be using a filler metal for the lower strength steel, but I was told the welds would have to be 3/4" fillets using ER70 , VS 5/16" fillets using the ER110.

At this point thats about all the info I have .

My next question would be, What plate would I use to match the A53? (Is there an A53 plate spec?)

Thanks in advance,
Carl
Parent - - By 803056 (*****) Date 01-09-2012 04:30
You've been around long enough to know what our next question is.

Al
Parent - - By ctacker (****) Date 01-09-2012 06:11
I forgot to mention D1.1
Parent - - By fschweighardt (***) Date 01-09-2012 13:18 Edited 01-09-2012 13:27
what edition?

Overall, you seem to have the basic requirement figured out.  I would get WRITTEN instructions from the capital "E" Engineer as to the joint requirements, etc.  One item that I have not noted elsewhere in the code is 4.12.3(4) mentions that test conditions should approximate actual production conditions as closely as possible, which makes sense.  I have not seen that paragraph anywhere else.

Have to look around a bit to see how you could get a piece of plate that meets A53 specs.  There are a couple of grades, and a few types, which refer to method of manufacture
Pipe
    
http://www.mcneilus.com/Specifications/SpecBook/WebPageSpecbookContents/P.13.htm

here is some summarized data.  as you can see, there is a good bit of difference in Grade A and B as far as UTS and a bit of difference in yield
Parent - - By ctacker (****) Date 01-09-2012 13:50
2010 Edition,
Thanks fschweighardt
Parent - - By 803056 (*****) Date 01-09-2012 14:40
You should be able to substitute any plate material found in Group 1, Table 3.1 for the A53.

It sounds like you are designing and fabricating to AISC requirements. If that is the case, the designer must consider the maximum unit stress permitted for each base metal, i.e., not to exceed 0.4 times the yield per table 2.3 (AWS D1.1-2010) or that permitted by AISC (if applicable).

The allowable unit stress of the base metal will become the limiting factor when the filler metal is grossly over matching the base metal as in this case.

The fillet weld deposited with the higher strength filler metal will sustain higher loads, but the weld will simply force the failure into the base metal either by failing along the toe through the cross section of the base metal if it is thin, or along the leg of the fillet weld if the base metal is thick.

Best regards - Al
Parent - - By ctacker (****) Date 01-09-2012 20:49
Thanks  Al,
I will pass this info on and see what comes of it, right now its still in the planning stages.
Parent - - By fschweighardt (***) Date 01-11-2012 01:24 Edited 01-11-2012 01:58
The math works just about right for the weld size reduction, and it looks like you could simulate the A53 with A36 plate.  I would have the Engineer sign off on the substitution.  The thing I wonder about is economics, How many of these do you have to do?  The WPS process will not be inexpensive, and the filler metal is pretty pricey also. 

What is your plate and pipe wall thickness? 

You have a 100KSI base plate, a .220 eff. throat 110KSI weld, which indicates that your pipe might be ~.500 and .700 36KSI material.  I think that with the joint configuration under discussion, you will have a .3125 x weld length of pipe doing all of the work. 

Lets say your pipe is 10" OD, then you have ~9.8in^2 of pipe that is effective.  You will have a very similar amount on the base plate, ~10.12 in^2.  Just for grins, you will have ~7.02 weld area (through throat). 

Do the multiplication, and you will see that if the base plate is given a relative value of 1, the weld will be 76% as strong as the base, and the pipe will be 35% as strong. 

If you used the full .75 fillet, you now miraculously have ~23.5" of weld area on the pipe and now could develop ~85% of the previous base strength, and if welded with 70KSI, the weld would develop ~120% of the previous base strength.

I would be shopping for a different base plate or a higher strength tube/pipe member or something

FYI these numbers are fast and dirty, so YMMV.
Parent - - By ctacker (****) Date 01-11-2012 06:21
I don't have much more info than whats posted. I was told the plans were stamped by an Engineer, now I am being told we will be making piles with the A514 being a helix like a drill bit.
Several hundred feet of weld involved.
I'm actually surprised they even asked about a procedure, I usually see a job about the time it hits production and get to see the "deer in the headlights" look when I start mentioning procedures and testing with the project managers.
Parent - By fschweighardt (***) Date 01-11-2012 13:08
I know the drill bit looking thing you will be building.  You have enough weld to where cutting labor cost is a big deal, so I get the notion of working with the 110KSI filler.  I am not sure the weld strengths have been looked at enough, but if the Engineer says its good, well its his a$$.  I might make a couple of FW break tests with the 5/16 110ksi andd one with 3/4 70ksi and show how easy the small welds will tear out of the low strength pipe
Parent - By fschweighardt (***) Date 01-11-2012 23:09
Bend tests will be interesting also, pretty sure all of the bend will be in the A53/A36 material.  Might have to go with a longtiudinal
Up Topic American Welding Society Services / Certifications / Fillet weld PQR question

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