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Up Topic American Welding Society Services / Certifications / Peening & Interpass Cleaning
- - By SammyShine (**) Date 10-03-2008 17:13
I'm writing a WPS. That has been tested and documented on a PQR. I have listed "As  Required" on Peening & Interpass Cleaning on the WPS.
Can someone please tell me what Peening could be used on a PQR?
Interpass Cleaning?

What I have listed on my PQR is:

Peening-Intermediate Weld Layers as required (I'm not really sure what this means-what is the purpose of peening?)
Interpass Cleaning- Wire Brush as required

What other methods could be used while testing?

I'm not a welder so I'm not sure that my questions are clear. I work in the office but I would like to know what it is I am typing when I'm filling out a WPS or PQR...not just fill in the blanks.
Parent - - By ctacker (****) Date 10-03-2008 17:26
this pretty much sums it up!
http://en.wikipedia.org/wiki/Peening

Any peening that is carried out on a weld should have been carried out on the weld procedure qualification test piece.
Parent - By SammyShine (**) Date 10-03-2008 19:05
Thanks for your reply.

Again, I'm trying to understand why I am writing these things on the PQR. The PQR states "Intermediate Weld Layers as required" so I am assuming this means the welder hammered the test piece between layers as he welded it?

Correct?
Parent - - By jwright650 (*****) Date 10-03-2008 18:57
Sammy,
Some may confuse using a pneumatic chipping hammer with peening...but if the user is deforming the weld surface to hide porosity or other discontinuities then yes, it would be called peening. However for light slag removal, these chipping hammers are acceptable. See AWS D1.1 C-5.27 regarding their explaination of acceptable/unacceptable peening.

In the design section of the code it also addresses peening in paragraph 2.20.6.6(3), and explanations given there as well.

Under interpass cleaning on my WPSs, I usually just state to remove slag....you can go so far as to specify how you want it done, or with what tools...ect....
Parent - - By SammyShine (**) Date 10-03-2008 19:11
Thank you for your reply.

Peening sounds like cheating. But I guess it's something that may have to be performed to compact a weld. So on a WPS,  I guess stating "as required" is OK. I will look at D1.1 C-5.27.

And cleaning can be done with a wire brush or chipping hammer for slight slag removal. Are there other methods?
Parent - - By ctacker (****) Date 10-03-2008 20:35
when welding a highly restrained weld, peening is also used to keep the weld from shrinking and introducing a crack into the weld.
Also some of our adapters on large earthmoving equipment call for the bottom toe to be peened using a rounded chisel to put a small groove around the weld, called toe peening.
Attachment: SKMBT_50008100312000.pdf (7k)
Parent - By 3.2 Inspector (***) Date 10-03-2008 20:58
Hmmmm...
Very informative :)

3.2
Parent - - By kipman (***) Date 10-04-2008 17:20
Tacker,
That toe peening sounds like quite a bit of work.  What sort of equipment did you use to do it?
Mankenberg
Parent - By SMTatham (**) Date 10-04-2008 17:34
Pneumatic hammer
Parent - - By ctacker (****) Date 10-04-2008 20:21
SMTathem has it right, we use a pnuematic hammer. works best if you put the trailing corner down and slide it along so its easier to guide. once you get the hang of it, it goes pretty fast! But for someone doing it the first time, It can turn into alot of work and make a guys arm feel like its gonna fall off!
Parent - - By kipman (***) Date 10-04-2008 20:29
Tacker,
We often use toe grinding to accomplish the same thing (fatigue improvement).  Do you know of any studies or other documents that talk about the fatigue performance of a structure using toe peening?
Mankenberg
Parent - - By ctacker (****) Date 10-04-2008 20:51
All I have are the specs, and we also have to stone grind the first 3 inches of the welds perpendicular to the weld joint. all the studies are proprietary information and because I don't have access to it, I cannot share that information, Sorry.
If I can get any information I will be gad to share it! That wikpedia link has some good info!

The jobs we are required to use the peening are castings welded to A514 plate and using E70T wire and the welds are highly restrained. peening is probably used after welding to help relieve the tensile stresses that develop in the weld metal and surrounding base metal on cooling. we also need to put temper beads on the upper toe next to the cast material. I'm still trying to figure all this out myself. hopefully someone else will have some input on the subject.
Regards, Carl
Parent - - By 803056 (*****) Date 10-05-2008 02:57 Edited 10-05-2008 03:00
Maybe I am misinterpreting something. If so, please forgive me.

A PQR is a record of what was done, not what might be done. Either the welder peened the weld or he didn't.

I see the same mistake made with other variables that are listed as ranges when the actual recorded values are what should be recorded. The groove angle was 48 degrees, not 45 to 60 degrees. The root face was 1/8 inch, not 0 to 3/16 inch. If the groove angle and root face varied that much it should be been tossed!

Travel speed, "as required". Bullstick! That's not even a range! That's like filling in box marked "Sex" on the employment application as - "would love some, thanks for asking".

Stringer or Weave: either - which was it? If the welder did use a few stringers and a few weave beads say so!

Post Weld Heat Treatment: Optional - No, either the test assembly was subject to PWHT or it wasn't!

I had one inspector ask me, "What book do I look in to find the values of voltage, amperage, and wire feed to list on my PQR?"

AHHHHHHHHHHHHHHHHHHHHHH! It feels so good when I stop banging my head against the concrete wall! :)

Off the subject: Henry, have you seen our mutual friend Brad K. lately? He and I had dinner a couple of weeks ago while I was in Pittsburgh!

Best regards - Al
Parent - - By ctacker (****) Date 10-05-2008 03:21
I think I said "Any peening that is carried out on a weld should have been carried out on the weld procedure qualification test piece. "

I hope your post wasn't directed to me! I don't think I ever said anything along the lines that you stated in your post. although I have seen a few PQR's written the way you mentioned. But not on any I have anything to do with.
Parent - - By 803056 (*****) Date 10-05-2008 03:40
Hello Carl;

I was refering to the statement in the original post:

"What I have listed on my PQR is:

Peening-Intermediate Weld Layers as required (I'm not really sure what this means-what is the purpose of peening?)
Interpass Cleaning- Wire Brush as required"

The wording sounds like it was intended for a WPS rather than a PQR.

I added my comment after yours, and it indents. It wasn't directed as a response to you or anyone in particular.

Just a question, is there a way to add a response with out "indenting"?

Best regards - Al
Parent - By ctacker (****) Date 10-05-2008 18:00
I thought so Al, but I got an email saying you replied to my post. I don't think there is a way to get rid of indenting.
Regards, Carl
Parent - - By SammyShine (**) Date 10-06-2008 17:55
Hi... You were refering to my post.

And yes...what is listed on the PQR is as stated in the post. The person I sent the PQR to didn't have a problem with the way it's worded. But I can definately see your concern. What actually happened during the test: Peening on intermediate layers as the Welder felt needed. Do you think the PQR should have stated "Intermediate Layers" period no As Req?

On the Interpass Cleaning...Wire brush was used by the welder an needed.
again...do you feel it should just state "Wire Brush.

Your input will be greatly appreciated.
Parent - - By ctacker (****) Date 10-06-2008 18:33
Was the weld actually peened, or just needle-gunned to chip the slag? and why would the welder decide whether it was needed or not?
Parent - By SammyShine (**) Date 10-06-2008 18:58
I am not a welder but I assume that because the WPS stated "As Required" he did what he felt was best.
Parent - By kipman (***) Date 10-05-2008 14:21
I also see this sort of thing often, and every time it surprises me.  It is not a difficult concept.  A PQR is a RECORD - so you record what actually happened.
However, it the world wasn't this way they wouldn't need guys like us.
Mankenberg
Parent - - By kipman (***) Date 10-05-2008 14:23
Thanks Carl.  I really don't trust wikipedia however, because entries like that could be written by guys like me.
Mankenberg
Parent - By 803056 (*****) Date 10-05-2008 22:30
You're absolutely right Kip. After all, who visits their doctor unless they has something that ails them.

Best regards - Al
Parent - - By 803056 (*****) Date 10-07-2008 00:41
That looks interesting. I saved it so I can read it when I get a minute. At the moment my feet are so sore from walking around FabTech, I just had to sit a while before going out to dinner.

Best regards - Al
Parent - - By 803056 (*****) Date 10-07-2008 01:25 Edited 10-07-2008 04:50
Hello Sammy;

There are several reasons to peen a weld. In all cases it is a controlled process that needs to be defined and implemented by the welded as defined by the engineer. It isn't something the welder should do at will.

Some of the reasons include:
-Improving the fatigue life of a weld by placing the weld toe in compression and increasing the time required to initiate fatigue cracks at the weld toe.
-Reducing residual stress in the weld due to shrinkage when the weld solidifies and as it contracts as it cools to room temperature.
-To reduce the residual stress in the weld to minimize angular distortion.

There are usually code restrictions on what layers can and can't be peened and how or if the peened surface is to be ground to remove peening marks.

It has already been mentioned that the marks made by slag removal (tools) are not considered peening.

The welder should be given specific instruction on how the test piece is to be welded. The welder's job is to follow those instructions to the letter. The PQR should be an independent verification of what materials were used, joint details, etc. and all those essential (and in my opinion, all the nonessential variables) variable applicable to the process. The data collected by the test witness and recorded on the PQR serves as the foundation to write the production WPS.

Just because a reviewer doesn't shoot your PQR down in flames isn't an acid test that it was complete or correct. It just means the reviewer knew less than the person that wrote it.

I remember one of my PQRs, I forgot to list the shielding gas used with GTAW. I was asked when I was going to patent my new welding process. Live and learn! Mud on the face, foot in mouth! You get the picture!

Best regards - Al
Parent - By SammyShine (**) Date 10-21-2008 18:41
"Just because a reviewer doesn't shoot your PQR down in flames isn't an acid test that it was complete or correct. It just means the reviewer knew less than the person that wrote it. " quote from 803056

Oh, I know. It's just that there were areas that he did correct.

And please don't think that I am coming up with these procedure...SCARY STUFF. There is someone directing me...who knows about welding ...but not the paperwork side of it.
Parent - - By jrw159 (*****) Date 10-07-2008 15:07
Al,
  You lucky dog!! I would give anything to have sore feet from an experiance like that. :-)

Have fun!!

jrw159
Parent - - By freewelder (*) Date 10-17-2008 08:22 Edited 10-17-2008 08:33
This is just great. You get a non-technical person to write a WPS/PQR. Saves a lot of money doesn't it? No wonder welding engineers are out of work. But due credit must be given to Sammy for trying to learn. If Sammy learns enough, she or he may be a welding engineer too.

Ps. As a footnote, in my experience, peening in welding isn't done by the welder although the guy who does the peening may be a welder. This is because it has to be done when the weld is still red hot in its plastic phase. After the weld has cooled and solidified, it is too late to peen. The only requirement I have seen for this is in the repair of castings. The aim is to compact the weld into the groove.
Parent - By hogan (****) Date 10-17-2008 13:29
Thank god you are here!
Parent - By Metarinka (****) Date 10-17-2008 19:36
interesting paper, it all makes sense
Up Topic American Welding Society Services / Certifications / Peening & Interpass Cleaning

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